Copyright: Copyright ®1995 Dynamic Living Media
Citation: (From the PC/Internet Lexicon ®1995 DLM)


Computing Terms and Phrases

  Usage instructions

Numerical

  386 enhanced mode

A

  A Manufacturing Language (AML)

  absolute path

  accelerator key

  access time

  active

  active matrix

  adapter

  address

  Adobe

  Adobe Type Manager (ATM)

  Advanced Interactive Executive (AIX)

  Advanced Technology (AT)

  airplane rule

  algorithm

  all points addressable (APA)

  alpha test

  alphanumeric

  American Micro Devices (AMD)

  Amiga

  analog

  analog-to-digital converter (ADC)

  angle brackets

  annotation

  anti-aliasing

  app

  Apple

  applet

  application

  Application Program Function (APF)

  application program interface (API)

  application-specific integrated circuits (ASIC)

  application window

  archive

  archive bit

  argument

  arithmetic logic unit (ALU)

  artificial intelligence (AI)

  ASCII file

  Ashton-Tate

  assembly

  associate

  Association of Shareware Professionals (ASP)

  Atari

  attribute

  audit trail

  AUTOEXEC.BAT

  AutoCAD, Autodesk Inc.

  Automatic Process Planning (APP)

  Automatic Identification Manufacturers (AIM)

  Automatic Storage & Retrieval System (ASRS)

  avatar

B

  back door

  background

  backup

  backward compatible

  banner

  base-level synthesizer

  BASIC

  batch

  basic input/output system (BIOS)

  battery (CMOS battery)

  benchmark

  Berkeley

  Bernoulli disk

  beta test

  Betamax syndrome

  binary coded digit/decimal (BCD)

  bit

  bit bashing

  bit bucket

  bitblt

  bitmap

  blinkenlichten

  blit

  boat anchor

  bogon, bogosity

  bomb

  Boolean (logical) operators

  boot

  boot(able) disk

  boot record

  boot sector

  bootstrap

  Borland

  branch

  break

  bubble memory

  Bubblejet

  buffer

  bug

  bullet

  bulletproof

  bundle

  burn-in period

  bus

  button bar

  byte

C

  C, C++

  cache

  call

  Canadian Standards Association

  canonical

  caret

  careware, charityware

  carpal tunnel syndrome (CTS)

  carriage return (CR)

  cascade, cascading menus

  CASE tools

  Cathode Ray Tube (CRT)

  cell

  central processing unit (CPU)

  Centronics

  chain

  character mode

  characters per inch (CPI)

  check box

  checksum

  Chicago

  child

  chip

  chipset

  CKHDSK.EXE

  clean room engineering

  clip art

  clipboard

  clock

  clock doubled;clock tripled;clock quadrupled

  clone

  cluster

  CMOS battery

  Coalition For Advancement Of Industrial Technology (CAIT)

  code

  code page information (CPI)

  cold boot

  collapse

  color depth

  COM port

  combo box (combination box)

  command interpreter, COMMAND.COM

  command prompt

  Common Business Oriented Language (COBOL)

  Commodore C-64

  common dialog

  communications port

  Compact Disk-Interactive (CD-I)

  compact disk read-only memory (CD-ROM)

  compiler

  complementary metal-oxide semiconductor (CMOS)

  Complex Instruction Set Computing (CISC)

  composite monitor

  compressed volume

  Computer-Aided (Drafting and) Design (CAD/CADD)

  Computer-Aided Design/Computer Aided Manufacturing (CAD/CAM)

  Computer-Aided Engineering (CAE)

  Computer-Aided Engineering Design System (CAEDS)

  Computer-Aided Manufacturing (CAM)

  computer-assisted process planning (CAPP)

  computer-aided software engineering (CASE)

  computer-based training (CBT)

  Computer Graphics Adapter (CGA)

  Computer Integrated Manufacturing (CIM)

  ComputerVision

  computer vision syndrome (CVS)

  concatenate

  CONFIG.SYS

  connectivity

  console

  context, context-sensitive, context menu

  contiguous

  Control+Alt+Delete

  control code

  control menu

  Control Program for Microcomputers (CP/M)

  conventional memory

  convergence

  cooperative multitasking

  copy protection

  copyleft

  core, core dump

  Core Wars

  Corporation For Open Systems (COS)

  crash, crash recovery

  Cray, Cray Research

  Creative Labs Inc.

  crippleware

  cursor

  cybernetics

  cyberpunk

  cyberspace

  cycle

  cycles per second (CPS)

  cyclic redundancy check (CRC)

  cylinder

D

  daisy chain

  daisy wheel

  data compression

  database

  database management system (DBMS)

  data file

  daughterboard

  dBASE

  debug

  Decision Classification Information System (DCLASS)

  default

  defragment

  delimiter

  desktop

  desktop publishing (DTP)

  destination directory

  device contention

  device driver

  Dhrystones

  dialog box

  digital

  Digital Audio Tape (DAT)

  digital delay line (DDL)

  Digital Equipment Corporation (DEC)

  Digital Research Incorporated (DRI)

  digital signal processor (DSP)

  digital-to-analog converter (DAC)

  Digital Video Interactive (DVI)

  digitally-controlled amplifier (DCA)

  digitally-controlled filter (DCF)

  digitizer/digitizing tablet

  dingbat

  DIP switch

  direct access storage device (DASD)

  direct memory access (DMA)

  directory (folder)

  directory path

  directory structure (directory tree)

  dirty power

  disk cache

  disk compression

  disk operating system (DOS)

  Distribution Media Format (DMF)

  document

  document window

  Document Content Architecture (DCA)

  dongle, dongle disk

  Doom

  DOS Protected Mode Interface (DPMI)

  dot pitch

  dot matrix printer

  double-click

  double-density

  downloadable font

  drag and drop

  drop-down menu

  dump

  Dvorak keyboard

  Dynamic Data Exchange (DDE)

  dynamic link library (DLL)

  dynamic random access memory (DRAM)

E

  Easter egg

  edge connector

  egg

  eight-dot-three

  Electronic Industries Association (EIA)

  electromagnetic enterference (EMI)

  electromagnetism (EM)

  ELIZA

  embed

  embedded command

  EMM386.EXE

  emulator, emulation

  Encapsulated PostScript (EPS)

  encryption

  end of block (EOB)

  end of field (EOF)

  end user

  Enhanced Expanded Memory Specification (EEMS)

  Enhanced Graphics Adapter (EGA)

  Enhanced Integrated Drive Electronics (EIDE, ATA, ATAPI)

  enhanced mode

  Enhanced Small Device Interface (ESDI)

  environment variable

  erasable, programmable read-only memory (EPROM)

  ergonomics

  errorlevel

  escape sequence

  execution, execution time

  expand, EXPAND.EXE

  expanded memory

  Expanded Memory Adapter (XMA)

  expanded memory manager (EMM)

  Expanded Memory Specification (EMS)

  expansion slot

  export

  Extended Graphics Array (XGA)

  Extended Industry Standard Architecture (EISA)

  extended-level synthesizer

  extended memory (XMS)

  Extended Technology (XT)

  extension

  external cache

  extra-low frequency electromagnetic radiation (ELF)

  extract

F

  facsimile (FAX)

  Fairchild

  Fast Fourier Transformation (FFT)

  FAX/modem

  Fear, Uncertainty and Doubt (FUD)

  femto-

  fifth generation computer

  file allocation table (FAT)

  file

  file control block (FCB)

  file handle

  file management

  file shuttle cable, File Shuttle Express

  filter

  firmware

  first-in-first-out (FIFO)

  first generation computer

  fixed disk

  fixed point

  flag

  Flash BIOS

  Flash ROM

  flat file database

  flicker

  floating point arithmetic

  floating point unit (FPU)

  floppy disk

  floptical drive

  FM synthesis

  fnord

  focus

  font

  footer

  footprint

  foreground

  format

  Formula Translation (FORTRAN)

  forward compatible

  fourth generation computer

  fourth generation language

  fractal

  fragmentation

  Free Software Foundation (FSF)

  freeware

  freeze, deadlock

  front end

  full path

  function key, fkey

G

  gallium arsenide

  gas plasma display (PDM)

  General Markup Language (GML)

  General Protection Fault (GPF)

  General Purpose Interface Bus (GPIB)

  gigabyte (Gb)

  glitch

  GNU Public License (GPL)

  graphic user interface (GUI)

  Graphical Environment Manager (GEM)

  Graphics Device Interface (GDI)

  Graphics Interchange Format (GIF)

  graphics mode

  grep

  greyscale

  groupware

H

  hack

  hacker

  handle

  hardcard

  hardwired

  head crash

  header

  heap

  heat sink

  Hercules Graphics Card or Hercules Graphics Adapter (HGA)

  Hewlett Packard (HP)

  Hewlett Packard Graphics Language (HPGL)

  Hewlett Packard Interface Bus (HPIB)

  hexadecimal, hex

  high-density (HD)

  high-level language (HLL)

  high memory area (HMA)

  High-Performance File System (HPFS)

  high-risk environment

  High Sierra

  HIMEM.SYS

  history

  host drive

  hotkey

  hotspot

  hue

  hybrid synthesis

  hypertext

I

  IBM-compatible

  icon

  image

  import

  Indeo

  Industry Standard Architecture (ISA)

  inkjet (Bubblejet)

  initialize, init, INI

  input device

  input/output (i/o)

  install

  integrate

  integrated circuit (IC)

  Integrated Drive Electronics (IDE)

  Intel

  interactive

  interactive computer graphics (ICG)

  Interactive Presentation Graphics (IPG)

  interactive video systems (IVS)

  interface

  interlacing

  interleave

  internal cache

  interrupt

  interrupt request line (IRQ)

  INTUIT

  IRQ conflict

J

  jaggies

  Jargon File. the

  jiffy

  joystick

  jump

  jumper

  justification

K

  kernel

  key disk

  keyword search

  kilobyte (K)

  kludge, kluge

  knowledge engineering (KE)

L

  label, LABEL.EXE

  laptop

  large scale integration (LSI)

  laser printer

  lasso

  launch

  last in-first out (LIFO)

  LHArc

  license

  light-emitting diode (LED)

  light pen

  line art

  lines per inch

  linker

  lint

  Linux

  liquid crystal display (LCD)

  List Processor

  locked file

  logical drive

  logical inferences per second (LIPS)

  Logical operators

  long filename (LFN)

  lost chain

  lost cluster

  Lotus

  Lotus/Intel/Microsoft (LIM/EMS)

M

  Macintosh

  macro

  mag tape

  magneto-optical storage

  mainframe

  Mandelbrot set

  Manufacturing Automation Protocol (MAP)

  master boot record

  math coprocessor

  maximize

  mean time between failures (MTBF)

  Media Control Interface (MCI)

  megabyte

  megahertz

  memory

  memory manager

  memory resident

  menu

  menu bar

  metafile

  metal oxide semiconductor (MOS)

  MicroChannel Architecture (MCA)

  microprocessor

  Microsoft

  MIDI adapter

  minimize

  mirror

  minicomputer

  mnemonics

  moby

  mode

  Modified Frequency Modulation (MFM)

  Modula

  monochrome

  Monochrome Display Adapter (MDA)

  motherboard

  Motion Pictures Experts Group (MPEG)

  Motorola

  mount

  mouse elbow, mouse shoulder

  Multi-Synch

  multitasking

  multithreading

N

  naming convention

  nano-

  National Computer Graphics Alliance (NCGA)

  National Software Testing Laboratories (NSTL)

  National Television Standards Committee (NTSC)

  natural language

  Netware

  neural network

  NeXT, NEXTSTEP

  nibble

  non-interlaced

  non-maskable interrupt (NMI)

  non-volatile RAM (NRAM)

  non-Windows application

  North American Presentation-Level Protocol Syntax (NAPLPS)

  Norton, Norton Desktop, Norton Utilities, etc.

  notebook

  Novell

  null modem cable, null modem

O

  Object Linking and Embedding (OLE)

  object-oriented

  object-oriented graphics

  object-oriented interface (OOI)

  optical character recognition (OCR)

  operating system (OS)

  Operating System/2

  original/other equipment manufacturer (OEM)

  orphan

  overlay

P

  pack, packed

  Page Description Language (PDL)

  page

  paging

  palette

  palmtop computer

  parallel port

  parallel processing

  parameter

  parent

  parse

  partition

  Pascal

  passive matrix

  paste

  patch

  path

  peek

  pel

  Pentium, Pentium Pro

  peripheral card, peripheral device

  permanent swap file

  Peipheral Component Interconnect (PCI)

  personal information manager (PIM)

  physical drive

  pico-

  pin grid array

  piracy

  pit

  pixel

  PKZIP

  Plasma Display Matrix (PDM)

  platform

  platter

  plotter

  Plug and Play (PnP)

  poke

  poll

  pop-up program

  port

  Portable Document Format (PDF)

  portrait, landscape

  power conditioner

  power on self-test (POST)

  PostScript (PS)

  PowerPC

  pre-emptive multitasking

  print resolution

  printed circuit board (PCB)

  printer font

  Professional Graphics Adapter (PGA)

  program

  Program Design Language (PDL)

  program group

  Program Information File (PIF)

  Programmable Logic Controller (PLC)

  programmable read-only memory (PROM)

  Programmed Data Processor model 10,11,20 (PDP-10)

  Programmed Inquiry Learning Or Teaching (PILOT)

  Programming In Logic (PROLOG)

  prompt

  propellerhead

  property sheet

  proprietary

  protected memory

  public domain

  pull-down menu

  pulse code modulation (PCM)

Q

  quarter-inch cartridge tape (QIC)

  Quarterdeck

  Quarterdeck Expanded Memory Manager (QEMM)

  Qualitas

  query by example (QBE)

  queue

  quick format

  Quicken

  QWERTY or Sholes keyboard; Dvorak keyboard

R

  radio button

  Radio Frequency Interference (RFI)

  RAMdisk

  Random Access Memory (RAM)

  raster

  raytrace

  read-ahead

  readme files

  Read-Only Memory (ROM)

  Read/Write Memory (RWM)

  real mode (Windows)

  real mode (DOS)

  record

  Reduced Instruction Set Code (RISC)

  refresh rate

  register

  registry

  relational database

  relative path

  removable cartridge drive

  repetitive strain injury (RSI)

  restore, restore button

  resolution

  Revisable-Form Text Document Content Architecture (RFTDCA)

  revision

  revolutions per minute

  rewritable optical storage

  robotics

  role-playing game (RPG)

  root

  routine

  Run Length Limited (RLL)

  runtime library

S

  sample

  scalable font

  scanner

  screen capture/screen grabber

  screen resolution

  screen saver, screen blanker

  script

  scroll, scroll buffer

  second generation computer

  sector

  seek time

  self-extracting archive (SFX)

  semaphore

  semiconductor

  serial port

  serif

  setup

  shade

  Shadow RAM

  share

  shareware

  (cut-)sheet feeder

  shell

  Sholes keyboard

  shortcut

  shortcut key

  shunt

  Situation Normal-all F***ed Up

  Small Computer Systems Interface (SCSI)

  smoke test

  sneakernet

  softfont

  software

  Software Publishers Association (SPA)

  Sound Blaster

  source code

  source directory

  spawn

  spreadsheet

  stack

  Stacker, STAC Electronics

  Standard Device Level Protocol (SDLP)

  standard mode

  static RAM (SRAM)

  String Oriented Symbolic Language (SNOBOL)

  Structured Query Language (SQL)

  studlycaps

  subnotebook

  subtractive synthesis

  Sun Microsystems

  Super VGA (SVGA)

  supercomputer

  superconductor

  swap file

  syntax

  synthesizer

  synthesis

  system clock

  SYSTEM.DAT, USER.DAT

  system disk

  System Request (SYSRQ)

T

  tab, tabstop

  table

  Tagged Image File Format (TIFF)

  Tandy

  tape backup unit

  target directory

  task

  task switching

  template

  temporary file; tempfile

  terminal

  Terminate/Stay Resident (TSR)

  TeX, LaTeX

  Texas Instruments (TI)

  Texas Instruments Graphic Achitecture (TIGA)

  text editor

  text file

  text mode

  text processor

  thin film transistor (TFT)

  third generation computer

  three-fingered salute

  three-state check box

  thumbnail

  thunk

  tile

  time bomb

  time slice

  toggle

  tone

  toner

  toolbar, tooltips

  trace

  track

  trackball

  tractor feed

  transistor

  trap

  tree

  trojan horse

  TrueType

  Turing machine

  turnkey

  typeface

U

  ultra-large scale integration (ULSI)

  Ultra-VGA

  Unicode

  undocumented feature

  uninterruptible power supply (UPS)

  unpack

  upgrade, update

  upward compatible

  upper memory area (UMA), upper memory block (UMB)

  USER.DAT

  user resources (USER.EXE)

  user supported software

  utility

V

  value-added reseller (VAR)

  vanilla

  vaporware

  VAX

  vector graphics

  Vendor-Independent Mail (VIM)

  version

  VESA Local Bus (VLB)

  vi

  VIC-20

  Video Electronics Standards Association (VESA)

  Video Graphics Array

  Video RAM (VRAM)

  virtual

  virtual disk

  virtual machine (VM)

  virtual memory

  virtual reality (VR)

  virtual storage access method (VSAM)

  virus

  VisiCalc

  Visual Basic

  volatile memory

  volume

  Von Neuman architecture

W

  wait state

  wallpaper

  warm boot

  Warp

  wetware

  what you see is what you get (WYSIWYG)

  Whetstones

  widow

  wildcard

  Winchester drive

  Windows NT

  Windows for Workgroups (WFWG)

  wire frame

  wizard

  wizard mode

  Wolfenstein

  word

  WordPerfect

  word processor

  word processing

  word wrap

  working directorysheet

  worksheet

  write once-read many (WORM)

  write precompensation (WPC/WPCOM)

  write-protect

X

  x-axis y-axis; x-y coordinates

  xBase

  XENIX

  X-Windows

Y

Z

  zap

  zero file

  Zero Insertion Force (ZIF) socket

  zero wait state

  Zork


Computing Acronyms

  Usage instructions

Numerical

  1GC

  2GC

  3GC

  386MAX

  4GC

  4GL

  5GC

  680x0

  8088

  8086

  80x87

  80186

  80286

  80386

  80486

  80586

  8514/A

A

  AAAI

  ABACUS

  ABET

  ABM

  AC

  ACM

  ADA

  ADC

  ADCAP

  ADF

  ADIH

  AFA

  AFP

  AI

  AIM

  AISP

  AIX

  ALGOL

  ALU

  AMD

  AML

  ANSI

  APA

  APF

  API

  APL

  APP

  APPC

  APSE

  APT-AC

  ASIC

  ASM

  ASP

  ASRS

  ASTM

  ATA

  ATAPI

  ATM

B

  BAD

  BASIC

  BCD

  BIOS

C

  C

  C++

  CAD

  CADD

  CAD/CAM

  CAE

  CAEDS

  CAGD

  CAIT

  CALS

  CAM

  CAMI

  CAPE

  CAPP

  CARIC

  CASA/SME

  CASE

  CAST

  CAT

  CATIA

  CBDS 2

  CBIOS

  CBM

  CBT

  CD

  CD-I

  CD-ROM

  CEO

  CGA

  CHGSC

  CIB

  CIM

  CISC

  CMOS

  COBOL

  COS

  CPI

  CP/M

  CPS

  CPU

  CR

  CRC

  crlf

  CRS

  CRT

  CSA

  CTS

  CULPRIT

  CV

  CVS

D

  DAC

  DASD

  DAT

  DBMS

  DCA

  DCF

  DCLASS

  DDE

  DDL

  DEC

  DIF

  DISSOS

  DIP

  DLL

  DM

  DMA

  DMF

  DOS

  DPMI

  DRAM

  DR-DOS

  DRI

  DS/DD

  DS/HD

  DSP

  DTP

  DVI

E

  EAROM

  ECC

  ECMA

  EDP

  EMS

  EEMS

  EGA

  EIA

  EIDE

  EISA

  ELF

  EM

  EMACS

  EMI

  EMM

  EMS

  EOB

  EOF

  EPA

  EPROM

  EPS

  ESPROLOG

  ESDI

F

  FASST

  FAT

  FAX

  FCC

  FFT

  FFTDCA

  FIFO

  FIPS

  FLASH BIOS

  FLASH ROM

  FMS

  FORTRAN

  FRANZ LISP

  FPU

  FSF

  FTC

  FUD

G

  GAA

  GCP

  GDI

  GEM

  GIF

  GML

  GNU

  GNU-C

  GPF

  GPIB

  GPL

  grep

  GUI

H

  HCI

  HGC, HGA

  HLL

  HLLAPI

  HMA

  HP

  HPGL

  HPIB

I

  I/O

  IBM

  IBM PC/AT

  IBM PC/XT

  IBM 3270 PC

  IC

  ICAM

  ICCA

  ICCP

  ICG

  IDE

  INI

  init

  INTERLISP

  IOCS

  IPG

  IRQ

  ISA

  ISAM

  IT

  IVDT

  IVS

J

  JPEG

K

  KB

  KE

  KLIPS

L

  LAN

  LCD

  LED

  LFN

  LHA

  LIFO

  LIM (LIM/EMS)

  LIPS

  LISP

  LPI

  LSI

M

  MACLISP

  MAP

  MBR

  MCA

  MCI

  MDA

  MFLOPS

  MFM

  MHz

  MIDI

  MIPS

  MIT

  MOS

  MPEG

  MPR II

  MS

  MSS

  MTBF

N

  NAPLPS

  NCGA

  NMI

  NSTL

  NTSC

O

  O/S

  OCR

  ODBC

  OED

  OEM

  OLE

  OOI

  ORACLE

  OS

  OS/2

P

  P-5

  P-6

  PAL, SECAM

  PC

  PC/AT

  PC/XT

  PCB

  PCI

  PCM

  PD

  PDF

  PDL

  PDM

  PDP-10/11/20

  PE

  PFKEY

  PGA

  PIF

  PILOT

  PKZIP

  PLC

  PL1

  PNG

  POM

  POS

  PnP

  POST

  PS

  PPM

  PROLOG

  PROM

  PSL

  PTP

Q

  QBE

  QEMM

  QIC

  QMF

R

  R/W

  RADAR

  RAM

  REXX

  RFI

  RFTDCA

  RIA

  RISC

  RLL

  RO

  ROM

  ROM-BIOS

  RPG

  RPG11

  RPM

  RS-232

  RSN

  RT

  RTIC

  RWM

S

  SAGE

  SAS

  SB, SB16

  SCSI

  SDLP

  SECAM

  SFT

  SFX

  SIMM

  SIPP

  SME

  SNAFU

  SNOBOL

  SPA

  SPOOL

  SQL

  SRAM

  SRVAM

  SSCAD

  ST506, ST412

  SVGA

  SYSRQ

T

  TECHMOD

  TeX, LaTeX

  TFT

  TI34010

  TI, TI-99/4A

  TIFF

  TIGA

  TOF

  TMRC

  TSR

  TWAIN

U

  UMA

  ULSI

  UMB

  UPS

  UVGA

  UNIX

V

  VAR

  VAX

  VB

  VDI

  VDM

  VDT

  VCR

  VESA

  VGA

  vi

  VIM

  VLSI

  VLB

  VM

  VMS

  VRAM

  VSAM

W

  WFW/WFWG

  WG

  WIP

  WO

  WORM

  WPC/WPCOM

  WP

  WPI

  WYGINS

  WYSIWYG

X

  XGA

  XMA

  XMS

  XT

Y

Z

  ZIF


enhanced mode, standard mode, real mode
386 enhanced mode

Obsolete term since the release of Windows 95, which runs in 386 enhanced mode only.  Beginning with Windows 3.0 and continuing with 3.1/3.11, Windows was capable of running several programs simultaneously, sharing the workload between all running programs (Windows 3.1 only), and accessing hardware functions without the need to work through DOS providing the appropriate software was loaded when Windows was booted.  These new abilities comprise the enhanced part of Windows operation and usually the only mode people ever use.

See also: standard mode, real mode (Windows), multitasking, IBM PC/XT, 80286, boot, Windows for Workgroups, real mode (DOS)


386MAX
386MAX (Qualitas)

386MAX is a memory management package for IBM-compatibles which is the most popular product produced by Qualitas.  Generally considered the second-rank product behind QEMM.

See also: QEMM,memory manager,IBM-compatible


Motorola 680x0-series microprocessor
680x0

Probably the most famous example of Betamax syndrome in computerdom is Motorola's microprocessor line which began with the 68000.  This was the first serious competitor to Intel's domination of the 16-bit CPU marketplace with the 80286 chip, a far more advanced design and implementation that showed its superiority on every computer that used it.  The original 68000 was used on Commodore's Amiga, Atari's ST series and Apple's Macintosh, all three of which outperformed comparably-equipped IBM-compatibles by a wide margin.  NeXT also opted for the Motorola processor, starting production with the 68030 and 68040 series processors.

It featured a 32-bit internal architecture and communicated with other hardware through a 16-bit bus, was never bound down by the 640K memory limit of DOS, was designed for expandability (later 68040 chips featured math coprocessors) and was easier to program than the Intel chips, making it ideally suited for the development of graphical user interfaces.

Motorola has kept pace with Intel, releasing newer, faster, more capable versions of the 68000 which still retain the ability to run most software designed for the original 68000 chip.

See also: Motorola, Betamax syndrome, bit, bus, microprocessor, 80x86, Amiga, Atari, Macintosh, NeXT, conventional memory, Intel, graphical user interface (GUI)


80x86
The 80x86 Chip Chart

80x86 is a generic term used to refer to the part number designation for the Intel line of microprocessors used as CPUs in IBM-compatible computers and other electronics.  The same numbers have been used by other manufacturers, including Cyrix, AMD, Texas Instruments and others to describe their versions of chips with virtually identical characteristics and performance.

The following is a table of the most popular chips in the series and their relative capabilities.  Select the chip number to see more information or simply scroll through this topic to see information about all chips on this list.

8088	8086	8087	80186
80286	80287	80386SX	80386DX
80387	80386SL	80486DX	80486DX2
80487DX	80486SX	80486DLC	80586, 80686
P-5	P-6	P-24

8088: First IBM-PC CPU chip; operated at a speed of 3.5MHz on an 8-bit bus.  Engineered to address a maximum of 1Mb of memory; can address up to 32Mb with expanded memory cards.  Also known (slang) as the PC chip.

8086: Next generation IBM-PC/XT (Extended Technology) CPU; operated at speeds of 4.77MHz to 10MHz depending on the model and manufacturer (some clone chips were somewhat faster).  First chip to offer two-speed operation; the faster speed is known as "turbo", and this two-speed capability continues up to the 486.  Also known (slang) as the XT chip.

8087: Math coprocessor chip for 8088/8086 CPUs, and also usable on systems up to and including many 80386's which contained sockets for these chips.  Floating point math processor offered a significant performance increase for CAD and spreadsheet operations and made these applications barely livable.  Usually cost more than the CPU itself.

80186: First IBM-PC/AT (Advanced Technology) CPU; operated at speeds of 6MHz to 12MHz on a 16-bit bus.  Intel's limp response to Motorola's 68000 microprocessor; short-lived in the marketplace since the 286 was released soon afterward and 186 motherboards were prone to buggy behavior and early failure.  Introduced extended memory; the ability to add memory above 1Mb and address it through the use of software memory managers .  Also known (slang) as the 186.

80286: First serious IBM-PC/AT CPU.  The chip that truly set the AT standard.  Operated at speeds of 6MHz to 30MHz on a 16-bit bus.  Permitted the same extended memory capability as the 286.

80287: Math coprocessor chip for the 80286 series.  Beginning with the 80287, the coprocessor had to be speed-matched to the CPU chip, meaning that an 80287 16MHz would not ordinarily be usable when matched with an 80286 12MHz CPU.  These coprocessors were also usable on many 386 motherboards as inexpensive alternatives to true 80387 math coprocessors.  Usually cost as much as the CPU itself.

80386SX: Next in line after the 80286; operated at speeds of 16MHz to 33MHz on a 16-bit bus.  Originally introduced on IBM's Personal System/2 computers.  Introduced the facilty for Shadow RAM (the ability to map ROM memory into RAM for higher system performance).  The chip that made GUI's on IBM-compatibles possible years after everyone using the Motorola 68000 had them.  Also known (slang) as the 386 or 386SX.

80386DX: Offered twice the potential power of the SX and made Windows a viable operating system.  Also allowed for two types of memory at two different speeds, specifically for "cache" memory to accelerate most-used functions such as screen display rewrites and disk access.  Operated at speeds of 20MHz to 33MHz (Intel models) and up to 40MHz (AMD clone chips) on a 32-bit bus.  The chip that made OS/2 a viable operating system for the IBM-compatible.  Also known (slang) as the 386DX or 386; still used in some home electronics (e.g. microwave ovens); no longer manufactured for PCs by Intel as of 1994.

80386SL: The L was usually said to refer to Laptop, but in reality it stands for Low power consumption; designed for laptop computers.  Functionally identical to the 80386SX.

80387: Math coprocessor chip for the 80386 CPU series.  These made fractals, raytracing and other high-quality graphics and animation livable on IBM-compatibles.  Beginning with the 80387, the coprocessor had to be not merely speed-matched to the CPU chip but bus matched as well, meaning that an 80387DX 20MHz coprocessor (32-bit bus) would not ordinarily be usable when matched with an 80386SX 20MHz (16-bit bus) CPU.  Usually cost slightly less than the CPU.

80486DX: The original 486 chip; true 32-bit operation, includes a built-in math coprocessor.  Operated at speeds ranging from 20MHz to 50MHz.  Significant speed improvements over the 386 are due in part to the coprocessor and also in part to an ultra-fast 8K cache housed in the CPU itself which processed the most frequently accessed instructions at speeds much higher than RAM memory.  The chip that made Windows 95 possible and OS/2 livable.  Early models of 486DX chips were known for excessive heat and early failure, and most 486DX chips require cooling devices of their own for reliable operation.

80486DX2,3 or 4: A 486 CPU chip with supposedly a more durable construction to allow its processing speed to be tied to a system clock running at double or triple its normal rated speed.  (DX4-100 chips are not DX-25 chips quadrupled in speed, but rather are DX-33 chips tripled in speed).

80486SX: A chip that was never supposed to exist.  Operated at speeds of 25Mz to 50MHz.  Originally created by clone manufacturers (not Intel), this is a 486 chip without the math coprocessing circuitry.  Intel responded by offering their own 486SX chips which were essentially 486DX chips whose math coprocessors had been short-circuited at the factory.  Made 486 computers at 386 prices a reality.

80487DX: The chip that never existed, and a very ugly tale.  (See crippleware for details)

80486DLC, 80486SLC, 80486DRX2 etc.: 80486 clone chips manufactured by Texas Instruments, Cyrix, AMD and others.  Various performance and compatibility specifications.  "LC" usually stands for "low consumption" (of power) and while these chips were designed for laptop and notebook computers, many found their way into home computers as well.

80586, 80686: Not acknowledged by Intel to be true model numbers for this series of chip, since Intel failed to trademark the numbers.  Used by some clone chip manufacturers and sellers to describe their Pentium-level CPUs.  See P-5, P-6, Pentium, Pentium Pro.

P-5 (Pentium): Original name for the Pentium microprocessor, successor to the 80486.  In addition to the 486's features Pentium offered speeds ranging from 60MHz to 133MHz, a 64-bit memory data bus and a larger internal cache (16K) than the 486.  The first production runs of 60MHz chips were the ones with the famous math flaws; no other speed of Pentium chip was affected.  Early models of Pentiums were also known for excessive heat and early failure.  Among its other  performance-enhancing features are branch prediction, which tries to guess program instructions and pre-execute them to save time (just in case the prediction is right), and superscalar construction with the equivalent of over three million transistors.

P-6 (Pentium Pro): Just released at this writing as the Pentium Pro, supposed to be the successor to the Pentium but provides an improvement in performance more in line with a hopped-up Pentium than a new generation of microprocessor.

P-24: Pentium Overdrive chip designed to operate on 32-bit bus motherboards (specifically upgradeable 486 motherboards) to improve performance.  Supposed to be direct plug-in replacements for the 486 but do not provide nearly the improvement in performance of a Pentium chip on a Pentium-oriented 64-bit motherboard.


8514/A

IBM standard for video display; used primarily for low-end CAD applications.  Not widely used now but emulated on most newer monitors since many manufacturers released video drivers compatible with the specification.

See also: Super VGA, CAD, emulation, device driver


ABACUS

A programming language


ABET
Accreditation Board For Engineering and Technology (ABET)

Organization responsible for accreditation of manufacturing-related curriculum and skill standards.


accelerator key

Accelerator keys are special keys used in programs which are used to access its most-used functions with just a keystroke.  For example, many helpfiles with alphabetical menus such as this one use accelerator keys so, for example, you could press G to automatically jump to topics beginning with G.  Accelerator keys differ from hotkeys in that only one key needs to be pressed to make the desired jump.  Hotkeys usually require two or three keys to be pressed simultaneously.

See also: hotkey


access time
access time (seek time)

The time required for a device to produce output after it receives a request for data at a specific address or physical location.  Usually used to refer to memory chips or hard disks.  Hard disk access times are measured in milliseconds (thousandths of a second) while memory access times are usually measured in nanoseconds (billionths of a second).  Chip access times are usually several hundred times smaller (and thus faster) than disk access times.

Seek time is usually used specifically to refer to access times for disk-based media.

See also: memory, chip, hard disk


ACM
Associaton for Computer Machinery (ACM)

Professional organization formed in the late 1940s for the development and promotion of computing standards.


active

Refers to the state of a given item in the computing environment, whether a program, window, icon, file or other object.  Windows is a multitasking operating system, and DOS can be a task switching environment, but neither can have two active input areas, or places you can click or type, at the same time.  This means only one window, program, icon or other object is available for use at one time.  The only exception is if you select a group of items to be worked on at the same time, in which case all items in that group become active at the same time.

See also: focus, multitasking, task switching


Ada

Computer language used by military for programming missiles; still in use; the language itself is freely available in various forms.  A Pascal-descended language that has been made mandatory for Department of Defense software projects by the Pentagon.  Hackers are nearly unanimous in observing that, technically.  Named for Augusta Ada Lovelace, the daughter of Lord Byron, who became the world's first programmer while cooperating with Charles Babbage on the design of his mechanical computing engines in the mid-1800s.  [Source: The Jargon File 3.0.0]

See also: Pascal, hacker


adapter

Two primary meanings in regard to computing; an additional meaning applies to personal computers.

Adapter usually refers to hardware used by a peripheral device to "adapt" it to the system on which it is installed.  Adapter card is used interchangeably with peripheral card to refer to circuit boards installed in computers to connect peripheral devices.

Devices used to convert one type of connection to another type are also referred to as adapters.  For example, adapters exist to convert the standard IBM-compatible keyboard plug type to a smaller plug type for use with a notebook computer, or for converting nine-pin serial port plugs and sockets to 23-pin and vice versa.

Adapter can also refer to a power supply adapter transformer used for hardware attached to a computer.  Many speaker systems used by home PCs require "power packs" or "adapters" (sometimes called wall pack adapters by manufacturers) to supply power in place of batteries.

See also: peripheral device, Shadow RAM, IBM-compatible, serial port


ADCAP

Advanced Capabilities


address

In general computing, address refers to a specific location in memory, and is usually defined in hexadecimal notation.  For example, Windows displays the address, or memory location, of the conflict whenever a General Protection Fault occurs.

See also: General Protection Fault (GPF), hexadecimal


Adobe

Adobe Systems Inc. has been a longtime player at several levels in personal computing, as a developer of software for the end user and in the establishment of standards for file formats on several platforms.  They are perhaps best known for developing the PostScript language used in desktop publishing and for transporting documents cross-platform, and more recently for introducing the Portable Document Format, a hypertext-capable document format usable on all major computing platforms.  They have also been major players in still graphics as producers of the industry standard Photoshop software for manipulating graphical images, and their Type 1 scalable font format is still in use on all platforms either as the primary font type or as a substitute for TrueType.

See also: PostScript, Page Description Language (PDL), Page Description Language (PDF), Adobe Type Manager, TrueType, scalable font, platform


Adobe Type Manager (ATM)

This is a software product developed by Adobe for IBM-compatible, UNIX and Macintosh computers that permits a type of scalable font that conforms to the Adobe Postscript Type 1 specification to be used on that system by one or all programs capable of using scalable fonts.  Next to TrueType, it is the most common scalable font format in use today, but lags far behind TrueType's popularity thanks to TrueType being the Windows standard.

See also: Adobe, font, scalable font, TrueType, typeface, Postscript, IBM-compatible


AFA
Advanced Function Array (AFA)

Ultra-high resolution graphics standard for IBM monitors in the mid-1980s, rarely seen now.

See also: PGA, 8514/A


AFP
Advanced Function Printing (AFP)

IBM printing capability with variable font, size, density and spacing.

See also: font


AIX
Advanced Interactive Executive (AIX)

IBM UNIX-based operating system for RT PC, one of the six most popular flavors of UNIX operating systems.

See also: UNIX, operating system


APPC
Advanced Program-to-Program Communications (APPC)

IBM protocol for peer communications between diverse network systems.


airplane rule

"Complexity increases the possibility of failure; a twin-engine airplane has twice as many engine problems as a single-engine airplane."  The Murphy's Law of programming, and the apparent current mindset of the computer industry, noted particularly by the fact that average complexity in software is increasing at approximately twice the rate of the average processor's power.

See also: central processing unit (CPU), Von Neumann architecture


ALGOL

Programming language; an acronym for ALGOrithmic Language.


algorithm

A predetermined set of instructions for solving mathematical problem in a given number of steps.  Algorithms function by applying a step-by-step procedure that insures a specific outcome or solution a specific problem.  An essential aspect of computer programming.


APA
all points addressable (APA)

Seldom-used alternative term for "bitmapped" graphics; individual pixel display and manipulation.

See also: pixel, bitmap


alpha test

Usually refers to an initial testing phase of a software package or program in which the programmer knows the software is incomplete but submits it to others for testing anyway to get advance information on possible bugs.

See also: beta test, software, program, airplane rule


alphanumeric

Generally refers to a sequence of characters, usually a code of some sort or a field of data, which can contain both digits and alphabet.  The data on a name and address label is alphanumeric, because it contains both alphabetical characters and numbers.


AC
alternating current (AC)

A method of transmitting electricity in which the two halves of the circuit alternate between positive and negative electrical charge between 45 and  60 times per second; used mainly in North America.


AML
A Manufacturing Language (AML)

IBM-developed programming language for robotics applications.

See also: robotics


AAAI
American Association For Artificial Intelligence (AAAI)

Organization formed in 1981 to further research into artificial intelligence.

See also: artificial intelligence


American Micro Devices
American Micro Devices (AMD)

Usually referred to simply as AMD, this manufacturer has been Intel's biggest competitor in the CPU chip manufacturing market for PCs for a decade.  AMD first came to prominence by marketing a low-cost "clone" of Intel's 8086 chip, the heart of the IBM PC/XT computer, and have since managed to keep up with Intel chip for chip, now offering alternatives to Pentium chips.  Although they produce other products, AMD is primarily known as a CPU manufacturer.

AMD's clean room engineering produces a chip that behaves in exactly the same way as the Intel processor when used on an 80x86/DOS platform, and with the benefit of having a model from which to work (Intel's), AMD has usually been able to produce CPUs that outperform Intel's while offering a very high degree of compatibility.  Unfortunately, in 1994 the courts found that AMD had not in fact clean room engineered their 486DX chips but instead had stolen Intel code outright, and they were forced to re-engineer, resulting in a temporary market shortage of 486 chips late in the year.

Other well-known manufacturers of "clone" CPUs are Texas Instruments and Cyrix.

See also: Intel, central processing unit (CPU), 80x86 IBM PC/XT, clone, Pentium, platform, IBM-compatible, clean room engineering


American National Standards Institute (ANSI)

This organization is responsible for approving US standards in many areas, including computers and communications.  Standards approved by this organization are often called ANSI standards (e.g., ANSI C is the version of the C language approved by ANSI).  ANSI is a member of ISO.  [Source: NNSC]

ANSI standard protocols are used in telecommunications to define standard character sets for low-resolution graphics and menuing in terminal software.

See also: International Organization for Standardization (ISO), escape sequences, C


ASTM
American Society Of Testing And Methods (ASTM)

Organization responsible for ASTM specifications.


American Standard Code for Information Interchange (ASCII)

A standard character-to-number encoding widely used in the computer industry.  Originally the numerical control (NC) tape punch format with odd parity (odd number of holes per tape row) used when paper tape was the common method used for storing computer information.  Now used mainly to define the set of characters used in most computers as keyboard-enterable characters (a total of 256)


Amiga

The successor to the Commodore C-64, the Amiga was Commodore's flagship computer until they concentrated on becoming primarily IBM clone manufacturers early in the 1990s.  The Amiga was based on Motorola's 68000-series chip and offered a graphical user interface as well as command-line operation (AmigaDOS), making it more versatile in that respect than the Macintosh or Atari ST, but never a serious contender to Mac's supremacy in the 68000-based PC class.  It was a superb graphics and game computer with capabilities which were never fully exploited in the marketplace and suffered unfortunate operating system bugs.  It was the first popular PC brand capable of multitasking.

The Amiga still maintains a loyal following of users.  It is primarily used today in commercial video production.

See also: C-64, Macintosh, Atari, 680x0, multitasking, graphical user interface (GUI), clone, multitasking


analog

In computing terms, any thing or event which is not expressible in terms of integers, i.e. 0's and 1's, or fixed states, i.e. on/off.

See also: digital, toggle


ADIH
analog display interface hardware (ADIH)

Interestingly, the monochrome screens common to early PCs were usually digital; almost all new monitors use an analog signal.

See also: analog, digital, monochrome


ADC
analog-to-digital converter (ADC)

An electronic device used to convert kinetic signals such as light, sound or touch into binary information.

See also: digital-to-analog converter, binary


angle brackets

Refers to the < and > characters.  These brackets are used to surround formatting commands in commonly-used languages such as SGML and HTML.

See also: format


annotation

Annotations are usually personal notes or comments attached to a Windows helpfile.  For example, a note could be added to this helpfile by clicking Edit and selecting Annotate.  Windows displays a Notepad-like text box where you can type and save your notes.  The next time you view the helpfile, that note is visible in the helpfile as a paper clip you can click to view the annotation.  Create a test annotation now to see how this works.


antialiasing
anti-aliasing

Angled lines drawn by computer graphics often look jagged because of the way pixels are laid out on the screen.  Anti-aliasing is a method of reducing that jagginess by varying the shades of the colors around the edges of a particular graphical object to create a smoother blend with the background and thus a less jagged appearance.  Usually done with fonts to improve readability and reduce reader stress.

See also: pixel, bitmap, jaggies


APF
Application Program Function (APF)

IBM interface component to PACS application programs


APL
A Programming Language (APL)

General purpose language for desktop publishing work, scientific computing and teaching mathematics.


APP
APP, app

Automatic Process Planning: self-generating process planning software system.

Also app: an appreviation for application, or program designed for data creation or processing.

See also: application, software, program, utility


Apple Computers

Sunnyvale, California-based Apple Computers are best known today as manufacturers of the Apple Macintosh PC, a graphically-based, integrated PC with a proprietary operating system.  For more than a decade it has been considered "the" alternative to IBM-compatible/Microsoft PC computing.

See also: proprietary, Macintosh, graphical user interface (GUI), Amiga, Atari, Microsoft, Commodore C-64, IBM-compatible, PowerPC

Trivia:

Apple began as the American dream: two young whiz-kid hackers named Steve Jobs and Steve Wozniak who essentially built the first Apple computers in a basement.  The Apple ][ went on to become the first popular home computer and a market leader until the introduction of Commodore's C-64, thanks to the low price and high performance of these computers, which came standard with an unheard-of 32K of memory.


applet

A mini-application...sort of.  Applet is a term usually reserved for self-contained programs that run within programs; programs that could run as stand-alone applications but instead use another program to launch.  Examples of applets are the programs which are launched from icons within Windows' Control Panel, and the Microsoft Draw and the Windows 95 Add/Remove Programs wizard.

See also: program, application, icon, wizard


application

A program that performs a function directly for a user.  FTP, mail and TELNET clients are examples of network applications.  Spreadsheets, word processors and games are examples of personal applications.

See also: program, app, applet, utility


application program interface (API)

Tool used by programmers to access specific operating system functions and peripheral devices.  Customarily, programmers follow an API specification set down by the developer of the operating system he/she is writing for.

See also: operating system


ASIC
Application-Specific Integrated Circuits (ASIC)

ROM chips dedicated to pre-defined applications, such as MPEG decoder chips built into a video card.

See also: integrate, integrated circuit, MPEG, read-only memory (ROM), chip


APSE

Application Program Support Environment


archive

Strictly speaking, an archive is a backup copy of data.  Archiving is the process of creating that backup.  Archive is also used as slang for compressed archive, meaning that the data has been reduced in size using mathematical algorithms for purposes to reduce storage requirements or telecommunications transmission time.  The backup set or tape cartridge created with normal backup software is an archive, as is a ZIP file.  Technically, even installation disks for programs are archives since they are backups of the original factory set, although that is not how they are usually viewed by users.

See also: backup, data compression, algorithm, PKZIP


archive bit

One of the bits in a file's attribute byte; used mainly to store a file's backup status; i.e.  the bit is set to 1 if the file has been backed up and to 0 if the file has not been backed up.  DOS and Windows automatically restore a file's archive bit to the NOT SET state (meaning not backed up) when changes are made to it unless specifically instructed not to do so.

See also: attribute, backup, bit


arithmetic logic unit (ALU)

The heart of a modern microprocessor, the ALU performs the various forms of basic math (addition, subtraction, multiplication, division and exponentiation, etc.) needed by most computer operations.  Logic relates to the logical method the ALU uses to fetch, name and identify specific data.

See also: central processing unit (CPU), floating point unit (FPU)


AI
artificial intelligence (AI)

The use of human knowledge by computers for problem solving.  Also refers to the science of developing "thinking machines" which behave in a human fashion.

See also: neural network, fifth generation computer, Turing machine


Ashton-Tate dBASE

Ashton-Tate is the American firm responsible for dBASE, the most popular database management system in existence still for IBM-compatibles even though a Windows version was not released until 1994.  Dbase is also used as novice slang for any database management system.

See also: database, Structured Query Language (SQL), IBM-compatible


ASM
assembly (ASM)

Programming language which allows for the maximum possible interaction between software and hardware with the fewest intermediary processes.  Assembler creates the fastest possible programs with the greatest possible flexibility since it does not depend on interpreter programs to manage a set of available instructions, but this speed comes at the expense of being extremely difficult to master and obsolete as soon as a new CPU chip design takes over the marketplace.  Assembly is known as a high level language since its programming instructions depend more closely on the actual capabilities of the chips themselves than other languages.

The .ASM extension is usually used to indicate source code for Assembly language programs.

Also: ASM: American Society Of Metals and Association For Systems Management.

See also: source code, high level language, BASIC, central processing unit (CPU), runtime


ASP
Association of Shareware Professionals (ASP)

An industry organization devoted to promoting and supporting authors of software who distribute their products via the shareware concept.  Extremely popular in the early 1990s; recently fallen out of popular favor due to their strict distribution and membership policies.  (e.g. ID software, the publishers of Doom and Wolfenstein, were denied membership due to technicalities).  Similar organizations: ASAD and STAR.  ASP is often used as a "Good Housekeeping Seal of Approval" for shareware software.

See also: shareware, user supported software, freeware


associate

A Windows term used to describe the process of tying files with specific names to a particular program so that the program launches automatically when the file is double-clicked.  Associations are made using Explorer (Windows 95) or File Manager (Win3.1/Win95) File menus.  For example, this helpfile is not specifically a runnable program.  It requires a program called WINHELP.EXE to run.

When Windows is first installed, it creates a default set of associations so that double-clicking many types of files - such as this helpfile - automatically loads the file into the program designed to use it.  This helpfile can also be loaded into other programs, but it will have to be loaded manually.  You can only associate a specific type of file to one particular program.

See also: Object Linking and Embedding (OLE), Dynamic Data Exchange  (DDE), extension


AISP
Association for Information Systems Professionals (AISP)

Trade association for systems analysts.


Atari
Atari (extended topic)

A California computer manufacturer (yes, a computer manufacturer) taken over in the early 1980s by the Tramiel family who had been at the helm of Commodore during the heyday of the Commodore C-64 and for a time during the development of the Amiga.

The company was, and still is, known primarily as manufacturers of computer games, such as the arcade machines Centipede, Battle Zone and Missile Command, and the home game machine Atari 2600 which was the first popular cartridge-based game console.

Atari is better known in Europe as manufacturers of the Atari ST, STe and TT lines of personal computers, which were top-ranked products behind the IBM-compatible and ahead of Macintosh in Europe for many years.  Many people felt the ST/STe/TT line could have been the great hope for inexpensive, high-performance GUI-based home computing, but it was not to be.

These elegant, compact machines featured an implementation of DRI's GEM interface, an enormous range of high quality software (particularly considering the size of the user base), built-in MIDI and digital sound capabilities as early as 1985 when the first STs were released, and the lowest retail prices of any comparably-powered PCs until the release of the TT line.

Some believe price was the eventual undoing of Atari, particularly in North America.  Many developers claimed Atari users were less willing to pay for quality software than users on other platforms, although this point is a matter of much dispute.

According to insiders, Atari instead fell victim to top-level management mistakes, and the ST/STe/TT line died a quiet death in the early 1990s.  Today Atari is best known as manufacturer of the 64-bit Jaguar game system, a fact lamented by many ex-users including this writer. [ - Cub Lea]

See also: Commodore C-64, Macintosh, Amiga, 68000, GEM, IBM-compatible


attribute

Generally speaking, a particular characteristic of a file or piece of data.  Used most common to describe the state of a disk file.  DOS and Windows use byte 11 of the file's directory entry and store a file's alterability (read/write), hidden or visible, system status and archive bit.

See also: archive bit, file, bit


audit trail

Used mostly in networking; a log of information used to trace activities or transactions in regard to a database.  Stems from bookkeeping terminology; a trail used to trace the source of problems or specific activities.

See also: database


AutoCAD, Autodesk
AutoCAD, Autodesk Inc.

AutoCAD, produced by Autodesk Inc., is considered industrywide to be the standard for vector graphic design, and has a price to match its reputation (basic AutoCAD packages for professional use have always run in the thousands of dollars).

Used for everything from high-end drafting and design to engineering, animation, simulations and both still and three-dimensional graphic arts, it is an extremely versatile and exceptionally well-supported product which appears likely to remain the industry standard through the end of the century.

See also: computer-assisted (drafting and) design (CAD), raytrace, vector graphics


autoexec
AUTOEXEC.BAT

A file used on DOS-based personal computer operating systems to configure system and software settings and parameters at boot-up.  See also: CONFIG.SYS, operating system, disk operating system (DOS)


ABM
Automated Banking Machine (ABM)

A computer-driven kiosk terminal designed for financial transactions not requiring interaction with a bank employee.


ADF
automatic description files (ADF)

Configuration files used with IBM's PS/2 family of computers.

See also: program information file (PIF)


AIM
Automatic Identification Manufacturers (AIM)

A not-for-profit trade association


APT-AC
Automatic Programming Tool-Advanced Contouring (APT-AC)

Popular numerical control (NC) programming language in manufacturing.

See also: NC


ASRS
Automatic Storage and Retrieval System (ASRS)

Computer controlled, high density, rapid retrieval storage system.


avatar

"Maker and destroyer of worlds"; term used to describe the root on some UNIX systems.

See also: root, UNIX


back door

A hole in the security of a system deliberately left in place by designers or maintainers.  The motivation for such holes is not always sinister; some operating systems, for example, come out of the box with privileged accounts intended for use by field service technicians or the vendor's maintenance programmers.  [Source: The Jargon File 3.0.0]

See also: hacker


background and foreground

Usually refers to how the computer is handling a specific program or process.  Multitasking operating systems such as Windows have to have a way of prioritizing the many tasks they perform, so they assign certain levels of processor access to each running program on a system.  Foreground applications, which are the applications the user is usually most interested in, are those with windows open and up-front, and they get the lion's share of the processor's computing power.  Background operations divide up the remaining processor time according to parameters set by the user or the program itself.

Background can also mean backdrop, as in a graphic or picture used to decorate a program or the Windows desktop itself.

See also: parameter, multitasking, wallpaper


backup

Strictly speaking, backup refers to an archived copy of a file or set of files, regardless of where this archive is stored.  Practically, backup also refers to the process of creating archived copies of data, and is used as one word, "backup", rather than two, as in "When are you going to backup that hard disk?"

The high vulnerability of magnetic and optical media to damage makes regular backups a critical part of routine file management for all computer users, since the data created on a computer is usually much more valuable and difficult to replace than the programs used to create that data.

Ideally, all important data should be backed up twice, and one copy of the backup stored a safe distance from the location of the computer to protect against loss of backup media in the event of theft or damage to the computer.

See also: archive, hard disk, tape backup, WORM


backward compatible, forward/upward compatible

Refers to engineering which allows users of a given product to continue to function with hardware or software intended for older versions of the product.  DOS is a backward-compatible operating system, in that the newest versions of DOS will (in theory if not in practice) run any properly written DOS program created for the earliest versions of DOS.

Forward compatibility generally refers to the expectation by a manufacturer that their product will comply with future specifications for a given system or part of a system.  It's rarely if ever something to bank on, and not something most consultants advise as an investment.

Upward compatibility refers to the ability of a product to perform just as well with higher-end versions of related products, or for a software product to generate data that can be imported into higher-end products in the same line or higher-end competitive products made by other manufacturers.  Once again, this is usually a believe-it-when-you-see-it claim.

See also: disk operating system (DOS), operating system, vaporware


banner

Usually refers to a graphical item, usually a fancy line often with text, used in desktop publishing.  Banners are usually placed at the top of the page and either extend from one margin to the other or are the only design element at the top of the page.

Also: the title page added to printouts by most print spoolers Typically includes user or account ID information in very large character-graphics capitals.

Also: Printing of long paper streamers with text and/or graphics on computer printers using hundreds of normal sized letter characters to form much larger characters.

See also: desktop publishing, spool


base-level synthesizer

A term for the most primitive type of sound synthesizer.  A base-level synth for Windows can play at least six notes on at least three different instruments (each instrument has its own channel) and at least three notes on three percussion instruments simultaneously.

See also: synthesizer, extended-level synthesizer


BIOS
Basic Input Output System (BIOS)

The software and hardware which govern a PC's data input-output functions.  These are usually controlled by specific chips in the computer which store semi-permanent information about the system's configuration.  Many BIOS functions are also managed by software in more advanced operating systems capable of taking over these duties.  Pertains to all data coming into and going out of the CPU, including data from disks, RAM, video, audio and any other forms.

See also: read-only memory (ROM), random access memory (RAM), central processing unit (CPU)


batch

A collection of commands.  Batch is also known as the rudimentary programming language on a command line operating system in which groups of typed commands can be combined into a text file.  This text file, when executed as if it were a program, executes the commands on the list in the order presented.

See also: macro, command interpreter, text file, operating system, prompt, program, execution


battery (CMOS battery)

On a PC, refers to a small cylindrical or disk-shaped battery usually located at the back of the motherboard or connected to the motherboard by a short cable.  This battery is used to preserve time, date and hardware configuration while the computer is powered down.  Believed by many industry watchers to be one of the dumbest design components of the IBM-compatible, since memory chips to hold this information can be created which do not require battery back-up to store their information.

See also: metal oxide semiconductor, motherboard, IBM-compatible


BASIC
Beginner's All-purpose Symbolic Instruction Code (BASIC)

A popular, problem solving, algebra-like, programming language.  Many variations; currently the most popular is Microsoft Visual Basic designed for the Windows operating environment.

See also: high level language, Visual Basic, source code


benchmark

Can refer to either a standard level of performance used to compare the relative performance of two similar pieces of software or hardware, or a piece of software designed to measure performance.  Benchmarking software is used to test the quality of a PC's software configuration and hardware components.

See also: MIPS, MFLOPS, Whetstones, Dhrystones


Berkeley

University of California at Berkeley.  Also refers to BSD (Berkeley Software Distribution), a flavor of the UNIX operating system available in both free and commercial versions.

See also: UNIX, freeware


Bernoulli disk

A flexible disk storage system that rivals hard disks for data capacity and access speed and based aerodynamics principles discovered by Daniel Bernoulli 1700s.  Best known is Iomega's Bernoulli Box, which uses removable 8-inch or 5.25" disk cartridges and is used primarily as a faster and higher-capacity alternative to tape backup units.

See also: hard disk, magneto-optical storage


Betamax syndrome

A slang expression stemming from the failure of the superior Sony Betamax videotape format to successfully capture market share from VHS, resulting in the vast majority of the consuming public being stuck with an inferior product.  Betamax syndrome can refer to both the tragedy of this type of situation and to the shoddy marketing techniques which often cause it.  Apple's reluctance to make it easy for clone Mac's to be created is an example of Betamax syndrome, as is the poor novice-level interface in OS/2 which contributed to Windows' overwhelming market superiority.

See also: clone, OS/2, interface


beta test

Testing phase of a software package or program in which the programmer believes the product is either complete or nearly complete and submits it for testing, usually to a substantial number of people working in different environments, to find out how it performs in real life.  Final adjustments are made based on user feedback before the product is actually released.

See also: alpha test


Bézier curves
Bézier

Bézier is a type of curve which is created using a mathematical formula.  It derives its name from French mathematician Pierre Bézier, and is used frequently in paint programs such as Paintbrush.  The curved lines created by using the curve tool in Paintbrush are Bézier curves, and the method Paintbrush uses to create these curves (manipulating a chosen point on the curve) is used by all such curve-creation tools.  This method allows for the quick creation of natural-looking shapes in an artificial environment, and is most commonly seen in vector graphics such as Windows' TrueType fonts, raytraced computer animation and CAD drawings.

See also: computer-assisted (drafting and) design (CAD), raytrace, vector graphics


binary

Base-2, a counting system using only 0 and 1 as digits.  The simplest numbering system.  (The standard counting or numbering system is Base-10).  Binary coding is the heart of all modern computing, since all computing consists of measuring or changing the state of a given position from 1 to 0 or vice versa.

Binary is also used as a relative term to distinguish between plain typewriter-style text and non-text data using the full ASCII character set.

See also: bit, byte, nibble, word, boolean, ASCII


Binary Coded Digit (BCD)
binary coded digit/binary coded decimal (BCD)

A type of positional value code in which each decimal digit is binary coded into 4-bit words.  Sometimes referred to as the 8421 code, from the value assigned to each of four bit positions (8-4-2-1).

Also: Binary Coded Decimal: System of combining binary bits in row to designate numerals and letters

See also: bit, byte, nibble, word


bit

Binary digit (also, less commonly, Built-In Testing): A bit is the smallest amount of data you can have on a computer.  A bit can be either a 0 or a 1. It's like a switch...one switch...that can be on or off.

Trivia

The term byte was coined by Werner Buchholz in 1956 during the early design phase for the IBM Stretch computer; originally it was described as 1 to 6 bits (typical I/O equipment of the period used 6-bit chunks of information).  The move to an 8-bit byte happened in late 1956, and this size was later adopted and promulgated as a standard by the System/360.  The word was coined by mutating the word "bite" so it would not be accidentally misspelled as bit.  [Trivial source: The Jargon File 3.0.0]

See also: byte,word, nibble, toggle


bit bashing

Any of several kinds of low-level programming characterized by manipulation of bit, flag, nybble, and other smaller-than-character-sized pieces of data; these include low-level device control, encryption algorithms, checksum and error-correcting codes, hash functions, some flavors of graphics programming, and assembler/compiler code generation.  [Source: The Jargon File 3.0.0]

See also: assembler, bit, flag, nibble, algorithm, checksum, encryption, compiler


bitblt

Any of a family of closely related algorithms for moving and copying rectangles of bits between main and display memory on a bit-mapped device, or between two areas of either main or display memory. [Source: The Jargon File 3.0.0]  Short for bit block transfer.

See also: bitmap, bit, blit, algorithm


bit bucket

The universal data sink (originally, the mythical receptacle used to catch bits when they fall off the end of a register during a shift instruction).  Discarded, lost, or destroyed data is said to have "gone to the bit bucket".  [Source: The Jargon File 3.0.0]


bitmap

Used to indicate a type of graphical data which depends on screen resolution, where the graphic is mapped to specific pixels on the screen.  Vector graphics do not depend on screen resolution for proper display; generally speaking, bitmaps do.  Most low-end and mid-line computer graphics are of the bitmapped variety.

See also: pixel, line art, vector graphics


blinkenlichten

ACHTUNG!  ALLES LOOKENSPEEPERS!

Das computermachine ist nicht fuer gefingerpoken und mittengrabben.  Ist easy schnappen der springenwerk, blowenfusen und poppencorken mit spitzensparken.  Ist nicht fuer gewerken bei das dumpkopfen.  Das rubbernecken sichtseeren keepen das cotten-pickenen hans in das pockets muss; relaxen und watchen das blinkenlichten.

[Trivial source: The Jargon File 3.0.0]

(Zie alzo: das seighnen vich seyen: Ist Nicht Eur Komputer, Hanzen Opf!)


blit

To copy a large array of bits from one part of a computer's memory to another part, particularly when the memory is being used to determine what is shown on a display screen.  Used heavily in graphics-intensive programming such as games development.  [Source: The Jargon File 3.0.0]

See also: bit, bit bashing


boat anchor

Like doorstop but more severe; implies that the offending hardware is irreparably dead or hopelessly useless.

See also: third generation computer


bogosity
bogon, bogosity

The degree to which something is bogus (insincere, lacks honesty, integrity or intrinsic worth).  Variations on bogosity are often passed around in hacker slang. A bogon is a standard measuring unit of bogosity.

See also: vaporware, hacker


bomb

Same as crash, probably used just as often.  Atari ST computers actually showed one or more small cherry bomb icons with lit fuses when a program crashed; the number of bombs indicated the cause of the problem.  Because the word itself sounds less violent than crash, it tends to be used more often to describe program crashes that do not halt the entire system.

See also: crash


Boolean (logical) operators

Named for George Boole, a 19th century British mathematician, Boolean operators in computing are operators which permit either/or (true or false) responses.  They are the simplest operators in programming, and are used both in software and in logic circuits as switches.  Boolean operators can be variable, and can permit item 1 AND item 2 to produce a response, item 1 OR item 2, or item 1 NOT item 2.


bootstrap
boot (bootstrap)

Boot is actually short for an ancient computer term (if any computing term could truly be called ancient) called bootstrapping.  When a boot is happening, the computer or program is running its own internal software -- pulling itself up by its own bootstraps, so to speak -- to prepare itself to work for you.  Also refers to code that launches a program.  For example, WIN.COM is a bootstrap program for Windows, or the boot program for Windows.

See also: boot disk, boot sector


boot(able) disk

Bootable disks, also known as boot disks, are floppy disks, hard disks or - more recently - CDs that can be used to start a system.  All disk-based operating systems, including DOS and Windows, require a bootable disk in order to start.  Bootable disks usually differ from normal floppy or hard disks in that they have a boot sector that tells the computer to start the operating system from this drive and a copy of the operating system files required to get the system up and running with at least basic functionality.  Bootable floppies are used today primarily as emergency recovery disks in case the hard disk refuses to boot on its own; almost all hard disks identified as Drive C are bootable on modern PCs.

See also: disk operating system (DOS), boot sector, operating system, system disk


boot sector

The first sector at the start of any disk, which contains essential information about the disk's structure and, if needed, how the operating system should be started.

See also: boot disk, sector


Borland

American software giant responsible for a number of extremely popular programs, among them the Quattro Pro spreadsheet, Paradox database, and the most popular C and Pascal programming packages in use for Windows and DOS.

See also: Pascal, spreadsheet, database


branch

Two meanings.  From a user's perspective, a branch is a segment of a directory tree, and represents a specific directory and any subdirectories it contains.  A subdirectory of this directory and ITS directories can also be a branch.  In programming, branch is used to signify that a program is expected to execute code in another part of the program when the branch command is encountered.  Branching refers to the process of creating code that moves from one set of instructions to one of several sets depending on the circumstances the program encounters.

See also: execute, directory, source code, tree


break

Usually refers to a temporary pause in a program so that it may debugged, or a halt to the program itself.  The Pause/Break key doesn't actually accomplish these feats on its own; in most cases the user is required to press Control-Break.

See also: debug, Control+Alt+Delete


BAD
broken as designed (BAD)

derogatory term used to describe buggy hardware or software.

See also: bug


bubble memory

Magnetic media suspended in crystal film, a form of NRAM (non-volatile RAM).  Can contain up to 500K, run slowly compared to DRAM.  Used for applications where mechanical disk drives are unacceptable.

See also: non-volatile RAM (NRAM), dynamic random access memory (DRAM), CMOS


buffer

A block of memory used by an operating system for temporary data storage.  In IBM-compatibles, these blocks (there are usually 15 to 40) are located near the top of conventional memory.

Also: any block of memory used for temporary storage in any device.

See also: conventional memory, clipboard, RAMdisk, IBM-compatible


bug

Unwanted or unexpected response from a piece of hardware or software.  Stems from an incident with an early Mark I computer at Harvard University in the 1940's.  U.S.  Navy officer Grace Murray Hopper found the remains of a moth blocking an electrical switch and disrupting the operations of the computer.  Since then, the process of filtering out unwanted program responses has been known as "debugging".

See also: debug


bullet

Bullets are:

•	Characters used to indicate an items in a formatted list.

•	Not usually used in numbered lists

•	Usually different from dingbats in that they are simple block or circle characters

•	Can also be dingbats at the discretion of the user

•	Used in this definition as an illustration

See also: dingbat, word processing


bulletproof

Used to describe the resistance of a program, operating system, or piece of hardware to glitches.  Generally means that the user has never seen it behave in any abnormal fashion that can be traced back to the hardware or software in question.

See also: bug, mean time between failures, system fault tolerance (system fault tolerance (SFT)), glitch


bundle

A computer marketing term that refers either to a package of separate products offered as part of a larger package or the act of creating such a package.  Bundling is standard practice in the industry as a competitive measure, and even operating systems now come as software bundles.  For example, Windows 3.1 came not just as an operating system, but bundled with a paint program, a word processor and a card game.  In turn, computer retailers bundle Window 3.1 or Windows 95 with their computers when they are sold to the public.

See also: OEM, VAR


burn-in period

A factory test designed to catch systems with marginal components before they reach the end user.  Usually a torture test designed to force borderline components to fail.

See also: smoke test


bus

The actual circuit traces or cabling used for data transfer among the various components of a computer system.  Buses are measured in terms of their bit width, or the number of signals they can carry simultaneously, and this is a major factor in the overall performance of a computer system.  PC's and XT's using the 8088 and 8086 chips respectively had 8-bit data buses, the norm for all PCs until the mid-1980s when the Motorola 68000 used on early Macs, Amigas and Atari's, and the 80286 AT CPU offered 16 bit bus width.  80386 and 80486 provide a 32-bit bus, and newer Pentium chips have a full 64-bit bus width.  In other words, there are 64 actual traces, or physical connections, between the Pentium and its components, which you can count as contact points on the edges of peripheral cards designed for these computers.

See also: 8088, 8086, 80286, 680x0, central processing unit (CPU), bit, Motorola, Pentium, trace


button bar

Literally, a bar of buttons.  The row of buttons at the top of this help window, which contains Contents, Search, Back and Print, is a type of button bar.  Button bars can be of this text type or iconic, meaning they contain icons, usually smaller than Program Manager or Explorer icons.  Iconic bars are also known as toolbars.

See also: toolbar, icon


byte

Bits organized together into a "word" to hold a symbol letter/number.  On most PC's, Eight zero's or one's; eight "bits" of information (not to be confused with "nibble".  (Byte is a flexible term; some computers use byte sizes as high as 36 bits.)  A byte is eight bits, or a combination of eight on-off switches.  It sounds pretty meaningless until you see bytes as similar to LED letters and numbers.  Think of each segment is a bit, and the combination of these segments, on or off, make up all the letters and numbers in your computer's alphabet.

See also: bit, nibble, word


C
C/C++

Computer programming language known for transportability; used on virtually all platforms and considered the standard for high-performance cross-platform computing.  C has several variants; the most commonly used today is C++.  Free versions of C++, known as GNU C, are available from the Free Software Foundation.

Trivia

The name of a programming language designed by Dennis Ritchie during the early 1970s and immediately used to reimplement UNIX; so called because many features derived from an earlier compiler named `B' in commemoration of its parent, BCPL.  Before Bjarne Stroustrup settled the question by designing C++, there was a humorous debate over whether C's successor should be named "D" or "P".  C became immensely popular outside Bell Labs after about 1980 and is now the dominant language in systems and microcomputer applications programming.  [Trivial source: The Jargon File 3.0.0]

See also: Free Software Foundation (FSF), platform, HLL, UNIX


cache
Software cache (extended topic)

There are two main types of caches in use on most modern PCs: hardware caches and software caches.  (Hardware caches are covered in the internal and external cache topic.)

A software cache reserves a block of memory reserved for use outside the normal function of the operating system.  Caching is used primarily as a method of dedicating areas of memory to specific functions as a means of speeding up the operation of the whole system or specific parts of it.  Caches usually operate transparently, meaning that the operator never notices them in use except insofar as they improve or degrade system performance.

In most cases, a cache is an intermediate temporary storage dump for data destined for a specific output device.

Print caches store data destined for the printer and feed that data to the printer port during times when the system is not otherwise in use, a handy feature with operating systems such as Windows 3.1 that dedicate the whole system to input/output when jobs such as printing and disk writes have been requested.  Disk caches store data destined for the hard disk or floppy disk and wait for free system time just like print caches, allowing the operator to return to work without waiting for the system to write data.

Read-ahead caching is often used on hard disks to accelerate their performance as well.  Blocks of data from the CD are read into memory or written to the hard disk where they can be accessed much more quickly when needed.

Caches are not always beneficial to the system; the amount of improvement or degradation of performance they provide depends on how they are used and the amount of memory available on the system for other tasks.

See also: internal and external cache, memory, hard disk, floppy disk


CAGD

Computer-Aided Geometric Design.

See also: wire frame, CAD


CAIT

Coalition For Advancement Of Industrial Technology: Congressional lobbying group encouraging industrial research.

Also Computer Aided Inspection and Test: system in which the computer assist with tasks like finite element analysis and design.


call

Could be considered "call to service" or "call in outside help".  A call is a request made by a program or operator for services provided by another.  The act of running one program from within another is known as "calling" a program.  Programs can also call routines encoded inside that program for specific functions.

See also: branchbranch, routineroutine, program, execute


Canadian Standards Association (CSA)

A non-profit Canadian organization dedicated to product testing for safety.  Best known internationally for their electrical and electronics standards for product safety which are used as a "Good Housekeeping Seal of Approval" for many American-made products and consumer electronics designed for sale in countries using AC electrical circuits.

See also: alternating current, International Organization for Standardizaton (ISO)


canonical

"According to religious law"; usually used to describe the authoritative nature of a document or list, most often with tongue in cheek, as in "Of course you know, PC/Internet Lexicon is the canonical source for file extensions for DOS and Windows."

See also: extension


CAPE

Computer Aided Production Engineering


caret

Two meanings.  Most commonly refers to the upward-pointing arrow symbol ^ above the 6 key on the typewriter keypad, usually accessible by typing Shift+6.  The caret is used by many programs to indicate the start of a control code (non-text) sequence of characters.

Also refers to a mark used in computer software to indicate the point at which text may be inserted.  In most programs either a flashing underscore, block or vertical line.  Also referred to in this context as a cursor, but since the mouse arrow is also referred to as a cursor, caret is often used to distinguish between the two types.

See also: control codes, cursor


careware, charityware

A form of software distribution in which the author makes their work freely available to all but requests a donation either to their chosen charity or the charity of choice of the user.

See also: shareware, freeware, user supported software


carpal tunnel syndrome (CTS)

A painful nerve disorder suffered by people who work with computers.  CTS gets its name from the narrow tunnel in the wrist connecting ligament and bone.  The median nerve, which carries impulses from the brain to the hand, and the tendons that open and close the hand are found in the carpal tunnel.  When undue pressure is put on the tendons, they can swell and compress the median nerve, causing numbness, weakness, tingling, and burning in the fingers and hands.  Usually caused by poor keyboard posture, lack of support for hands and wrists, and believed to be made worse by deficiencies of specific nutrients, most notably Vitamin B-6.  Once a true positive diagnosis is made, there is no known long-term solution other than surgery to the affected ligament to relieve the pressure and remove tissue.

As early as 1992, the US National Institute for Occupational Safety and Health was claiming that thousands of Americans were already afflicted.  It was only in 1994 that the term became widely known.  Some experts believe that CTS is severely overdiagnosed, and that most of those who have been diagnosed with CTS actually have a less severe and reversible, but no less uncomfortable, disorder known as tendosynovitis.

See also: ergonomics, mouse shoulder, computer vision syndrome, repetitive strain injury (RSI)


carriage return (CR)

Stems from typewriter terminology.  The assembly which holds the roller and paper guides is known as the carriage, and it must be returned to its home position on a new line for each new line of text to be typed.  In computing, a carriage return is a character typed by pressing the Enter key in an editing window which performs the same funcion.


cascade, cascading menus

In most cases, cascade refers to the way Windows lays out its windows.  When Windows overlays other windows so that you can see their titles but not necessarily the contents of any but the top window, the windows are said to be cascaded.  The effect is based on the idea of holding a hand of playing cards so that you see all their suits and values but none of the values except for the top card in your hand.

Cascading menus are a different matter.  They refer to menus that extend outward from other menus.  If you've seen a drop-down Windows menu with an arrow on it, clicked that menu item and seen a whole new level of menu choices, you have an idea of what a cascading menu looks like in Windows.

See also: tile, drop-down menu


CAST

Computer Aided Storage and Transportation


CRT
cathode ray tube (CRT)

The display tube used for computer generated graphics and/or text; also used in televisions.  So named because the device is a vacuum tube with one or  three electron "guns" that fire cathode "rays" at the phosphorescent coating inside the front of the tube.


CBIOS

Compatibility BIOS

See also: BIOS


CBM

Commodore Business Machines

See also: Amiga, Commodore C-64, VIC-20


CD
CD (compact disk; change directory)

Acronym for a form of single-sided digital media capable of storing 600-plus megabytes of information; high-capacity, short shelf life due to the frequent instability of the material used to create the digital image on the disk.  There was one standard format up until about 1990; currently there are several compact disk formats with varying capacities up to 4Gb.

Also: CD or ChDir: DOS command for changing from one directory to another.

See also: directory, CD-ROM


cell

Used in spreadsheet and HTML table formatting to indicate an individual element of the data table.

See also: spreadsheet, format


CPU
central processing unit (CPU)

The heart any computer, comprising arithmetic, control, and logic elements.  In Macintosh's the CPU is usually a Motorola 68000-series (e.g. a 68040); in IBM-compatibles there are several possible brands, usually referred to as xxx86 chips (e.g. AMD 80486-DX 80MHz, Intel 80486-SX 25MHz, Cyrix 80486-DC 33MHz, etc.)

See also: Macintosh, 680x0, 80x86, SX/DX,Intel, AMD


Centronics

The unofficial standard for parallel port data transmission in IBM-compatibles.  Developed by the Centronics Data Computer Corporation in the 1970s, it transmits data eight bits at a time as opposed to serial communications which can only transmit one.  While much faster than serial cable communications as a means of low-cost data transfer for two computers in close proximity, the Centronics parallel standard suffers from frequent electromagnetic interference errors when cable lengths of greater than 10 feet are used.

Centronics are also responsible for the parallel connector design used with most PC printers, and the "C" in the RS-232C parallel port designation, and the term "Centronics" can also refer to the plug or cable type used to connect most PC printers.

See also: RS-232C, serial port, parallel port, file shuttle cable, IBM-compatible


chain

Two primary meanings.  Chain usually refers to the segments of data which make up a file that is not laid out on a disk end-to-end, but rather broken up into sections and stored in different areas of a disk.  Less often, chain refers to the process of linking several commands together, such as chaining commands in a batch file or macro.

See also: contiguous, fragment, batch, macro, lost chain, daisy chain


check box

A small square box used in graphical operating systems for selecting options.  When checked, these boxes can appear greyed, blacked out, checked or crossed depending upon how they are designed and how many options they offer (most offer two options only: checked and unchecked). Unlike radio buttons, when provided in a list, none or several may be selected.

See also: radio button, three-state check box


checksum

A computed value which is dependent upon the contents of a packet.  This value is sent along with the packet when it is transmitted.  The receiving system computes a new checksum based upon the received data and compares this value with the one sent with the packet.  If the two values are the same, the receiver has a high degree of confidence that the data was received correctly.  [Source: NNSC]

Also used in normal computing for determining the integrity of a file; files whose checksums do not match the expected figure as set when the file was first created or installed are considered to be altered.  This makes checksums useful for determining potential virus infections and which files to include in a backup.

See also: virus, CRC, backup


CHGSC

Change Screen: the ChgSc key (usually found on terminals or workstation keyboards) moves the session from one defined screen profile to another.

See also: terminal


Chicago

This was the name used by Microsoft for the beta test (pre-release) version of Windows 95 and for in-house development of the new operating system.  The new software needed a working title, and this was the term used.  Microsoft traditionally chooses city names (Cairo and Daytona are the other two best-known examples) as working project names, and remnants of the "Chicago" name are still found in many areas of the operating system.

See also: beta test, Microsoft, operating system


chip

A computer chip is actually only a small fragment of what most people think of as a chip.  The chip itself is a small wafer of silicon fractions of an inch in size housed in plastic or ceramic material and surrounded by a grid of wires or connector pins that allow it to interact with other components.

See also: integrated circuit, printed circuit board, gallium arsenide


chipset

Two or more large-scale integrated circuits used to perform a set of functions in a PC which must be present together in order to work.  Usually refers to the chips on a motherboard used by the hardware for memory and bus management.

See also: large-scale integration (LSI),  very large scale integration (VLSI), ultra-large scale integration (ULSI), integrated circuit, motherboard, memory, bus


CHKDSK.EXE

A DOS program used for cleaning up hard disk errors, essential for most Windows 3.1 users.  DOS file management requires opened files to be closed by the operating system when a program ends so that their beginning and endpoints can be recorded in the file allocation table (FAT).  Unfortunately, when the system is turned off without closing all programs or after a fatal crash of Windows, these files are usually not closed properly.  When this occurs, stray data is left on the disk which could interfere with the integrity of other files or, at the very least, take up unwanted space.  CHKDSK.EXE is the program designed to correct such problems as well as several other errors in file and directory structure.

CHKDSK.EXE does not detect or correct errors in the magnetic media of a disk itself.  In DOS 6.0 and higher this job is reserved for Scandisk, which also includes CHKDSK.EXE's features.

See also: file allocation table (FAT), file, lost chain, lost clusters, directory structure


CBDS 2
Circuit Board Design System/2 (CBDS/2)

IBM's printed circuit board system; developed. by Bell Northern Research.

See also: printed circuit board


clean room engineering

A manufacturing method used in both hardware and software engineering in which a product is copied by examining its functions and attempting to duplicate them rather than copying the methods used to create such functions.

The idea is essentially to work with a "clean room", or no product, and built a product that behaves exactly the same way as the product being copied.  Since ideas cannot be copyrighted, clean room engineering neatly solves the problem of copyright infringement on products where the design is patented but not its behavior.

See also: emulator, clone


clip art

Graphic images used by word processing and desktop publishing.  Stems from the days when newspapers kept libraries of images and graphic art which were clipped with scissors for insertion into advertisements.  The preferred format is line art as opposed to the much more common bitmap format.

See also: word processing, desktop publishing, line art, bitmap


clipboard

A strange concept to most novices.  A clipboard is a special area set aside in memory designed to hold data which can be moved between applications.  Data copied to the clipboard remains available for pasting into any other program capable of handling that kind of data until such time as something new is copied onto the clipboard.  There are programs designed to allow the clipboard to stack and save copied data for later retrieval and use, but these are not standard features with Windows.  You get one clipboard buffer for one item only.

See also: paste, buffer


clock doubled;clock tripled;clock quadrupled
clock doubled, clock tripled, clock quadrupled

Generally refers to CPU chips designed to run at higher clock speeds, and thus process data faster than the previous generation chip.  DX2 chips are called clock doubled.  For example, a 486-DX4 100MHz CPU chip is essentially a clock-tripled (not quadrupled) 33MHz chip with a faster clock and, it is hoped, a more robust design to allow for the higher operating temperatures which this sort of modification produces.

Clock doubling was popular as far back as the 286.  Many hackers discovered that the clock crystal, which governed the timing of the CPU, could be replaced on many motherboards with a faster crystal which forced the CPU to run at a much higher speed than its model number suggested.  Many users were successfully able to turn 286-12MHz machines into 286-18MHz or even 286-25MHz machines simply by the replacement of a $5.00 clock crystal.  Unfortunately, this modification also pushed many motherboards and CPUs beyond their design limits and resulted in many disasters.  It is believed by many industry watchers that the clock-doubling trend noted most often with 486 chips tended to have the same effect on this series of chip, resulting in extraordinarily high operating temperatures, particularly among earlier models, and many early chip failures.

See also: central processing unit (CPU), 80286, 80486, mean time between failures, heat sink, cycle


clone

The term originated in genetics to indicate an exact genetic copy of a specific organism, but it has since passed into common usage as slang for identical copy.  In computing it has specific meaning.  When discussing hardware, it means hardware that precisely mimics the capabilities of a specific make and model of hardware which has become a standard but (usually) without violating copyright or patent laws.

The most common use for clone in computing is when referring to an entire computer.  Originally the common term was IBM clone, meant to indicate that the computer was 100 percent compatible with IBM's specifications for that particular type of computer.

Clone can also refer to software that mimics a common piece of more expensive or better-known software, although the term is usually reserved for software which mimics all of the original program's features.

See also: IBM-compatible


cluster

A group of sectors on a hard disk or floppy disk.  Floppy disk clusters are usually two sectors (one on each side of the disk) but because hard disks can include several actual disks or platters, the cluster size of a hard disk is usually the size of a sector times the number of platters times two.  Newer, more sophisticated hard disk formatting techniques now allow most hard disks to have two-sector clusters regardless of the number of platters.

See also: sector, floppy disk, hard disk, platter, lost cluster


cold boot

To start, or boot, a computer from a power-off state; physically "cold".  This is usually the last resort when restarting a computer, as most functions can be reset using a warm boot in less time and with less potential loss of data.

See also: boot, warm boot


collapse

Term used when discussing directory navigation using a program such as Explorer or File Manager.  Collapsing refers to hiding "branches" of subdirectories to clean up the view of the tree structure.

See also: directory, tree, branch


color depth

The total number of colors available for viewing on a video display is known as the system's color depth.  Windows 3.1 usually installs with a standard depth of 16 colors (although it may appear that there are more than 16, only 16 are be displayed onscreen at once at this depth) and Windows 95 will try to install with a depth of 256 colors.

Most modern SVGA-compatible monitors can offer color depths as high as 16 million colors.  This depth is possible because of the large number of gradations in electrical signals which can be sent to the monitor: a total of 256 gradations for each of the red, blue and green electron guns in the monitor.  Most systems will appear quite lifelike at 256 colors, and most standard video hardware will produce flicker, which leads to eye strain, at color depths higher than this.

See also: resolution, Super VGA, cathode ray tube (CRT), flicker


combo box (combination box

A dialog box that contains both text boxes and list boxes "in combination".  It provides an entry field into which a user can type, like a text box, and a list of options from which to choose, like a list box.  The File Open and File Save dialogs in Windows are examples of combo boxes.

See also: dialog box


command interpreter (COMMAND.COM)
command interpreter, COMMAND.COM

A command interpreter is the interface between the user and the operating system in a command-line environment such as DOS where specific commands must be typed rather than options selected by clicking.  A command interpreter takes typewritten instructions and converts them to instructions which the operating system can understand and use to tell the chips what to do.

COMMAND.COM is the program that handles command interpretation for DOS.

See also: disk operating system (DOS), operating system, command prompt, chip


Commodore C-64

Until the IBM-compatible came into its own as an affordable home computer, Commodore's C-64 series of personal computers were the most popular personal computers in history, and until very recently were the single biggest-selling make and model of computer ever, despite being out of manufacture for nearly a decade.

The C-64 featured a then-enormous 64K of memory, and Commodore's massive marketing effort insured an enormous amount of support from software and hardware developers.  As its popularity grew it gained a graphically-based operating shell called GEOS which is still implemented in some PC software, mouse and modem support, superb game play for products of this era, and literally tens of thousands of programs were available for it.  Considered by some to be the first true family PC, it fell out of market favor with the release of the Macintosh, Atari ST and Commodore's own Amiga line and reductions in the relative cost of IBM-compatibles in the mid-1980s.

See also: Amiga, Macintosh, Atari, graphical user interface (GUI)


COBOL
Common Business-Oriented Language (COBOL)

The first major common business application programming language.  Still in use.

See also: SNOBOL, FORTRAN


common dialog

Common dialogs refer to dialog boxes used by many different programs.  The identical File Open and File Save boxes used by Notepad and Paintbrush are examples of common dialogs.

See also: dialog box


CD-I
Compact Disk-Interactive (CD-I)

Phillips international's CD-ROM product designed for interactive entertainment.  Rumors say this poorly-supported product may find new life on the Internet as new computers are able to handle this disk format without the expensive hardware originally needed.

See also: CD, CD-ROM, DVI


CD-ROM
compact disk read-only memory (CD-ROM)

Optical disk used as data storage medium.  High storage (600Mb-plus per CD is possible now; several gigabytes will be common in a few years), short shelf life (the recorded surface begins to decay within a year or two).

See also: pit, CD, read-only, memory


compiler

A program  that translates high level programming languages into binary computer code.  This type of software actually builds programs from text instructions where an interpreter executes the instructions one by one.

See also: runtime library, high level language, binary, program, source code, execution


CMOS
complementary metal-oxide semiconductor (CMOS)

Type of electronic circuitry.  This circuitry is used in IBM-compatible computers for storage of critical information about the system's configuration.

See also: metal-oxide semiconductor, Non-volatile RAM,IBM-compatible


CISC (Complex Instruction Set Computing)
Complex Instruction Set Computing (CISC)

Pronounced "sisk", the basis for most PC microprocessing chips.  Complex instruction sets developed from the need for new models of old chips to be backward-compatible, even though chips with fewer instructions function at much higher performance levels.

See also: RISC, chip, central processing unit (CPU), backward compatible


composite monitor

Monitor that accepts standard TV-style video signals.  Seldom used on PCs now; older PCs such as some Atari's, Amiga's and IBM-compatibles used to accept composite video signal but the picture quality is generally too poor on affordable models to be practical for consumer use.

See also: Atari, Amiga, National Television Standards Committee (NTSC), IBM-compatible


CEO
Comprehensive Electronic Office (CEO)

Data General's business automation software; also Chief Executive Officer (head of a company)


compressed volume

A file that "represents" a disk when using disk compression software such as Stacker or Doublespace/Drivespace.  It's not an actual disk, or even a partition, but a section of a partition used to mimic a real disk or partition for the purpose of allowing a whole disk to be compressed and accessed as if it were a normal, uncompressed disk.

See also: Stacker, partition, data compression


CATIA
Computer Aided 3-D Interactive Application (CATIA)

IBM-marketed Dessault CAD software with solid and wire frame capability.

See also: CAD, raytrace


CAD
Computer Aided (Drafting and) Design (CAD, CADD)

Design development, analysis or modification through the use of computers.  A method of graphic design that primarily uses line drawings as opposed to painting on the screen for producing graphic output.

CAD is the generic term used to describe all such design.  CADD is often used to describe CAD with additional features of use to engineers and draftspeople, but the almost ubiquitous use of these features in CAD programs has blurred the line considerably.

See also: CAD/CAM, wire frame, raytracing, CAM


CAD/CAM
Computer Aided Design/Computer Aided Manufacturing (CAD/CAM)

Usually refers to design, drafting, and NC programming systems, both two- and three-dimensional but generally three-dimensional.  (Two dimensional CAD is often referred to as drawing or drafting.)  Newer animated 3-D CAD systems are sometimes referred to as 4-D CAD due to the addition of the dimension of time.

Also: CADAM: an interactive CAD/CAM system developed by Lockheed Inc. or IBM CAD/CAM.

See also: CAD, CAM, vector graphics, numerical control (NC)


CAE
Computer-Aided Engineering (CAE)

Computer assistance with tasks such as finite element analysis, design and development, or simulation of product performance prior to manufacturing.

See also: CAD, CAM, CAD/CAM


CAEDS
Computer-Aided Engineering Design System (CAEDS)

IBM integrated design system for solving stress/heat/design problems in engineering.

See also: CAD/CAM, integrate


CALS
Computer-Aided Logistics Support (CALS)

Department of Defense program to apply communications and technologies in logistics.


CAM
Computer-Aided Manufacturing (CAM)

Development of manufactured end product through computer assistance.

See also: robotics, CAD, CAD/CAM


CAMI
Computer-Aided Manufacturing International (CAMI)

International consortium of companies doing CAM research and development work.

See also: CAM, CAD/CAM


computer-aided software engineering (CASE)

CASE refers to tools for programmers, analysts, and systems engineers for planning and documentation of their work, logging of system support, and design and analysis of systems.  Modern CASE tools are usually integrated packages which are considered essential for all consultants, but prior to the late 1980s CASE tools tended to be extremely expensive mainframe-only software.

Also: CASE: Common Application Service Elements

See also: integrate, mainframe


CAPP
computer-assisted process planning (CAPP)

Software that assists with the creation of process plans.


CASA/SME
Computer and Automated Systems Association (CASA/SME)

An SME affiliate specializing in CIM technology.

See also: SME, CIM


CBT
computer-based training (CBT)

Educational software (and occasionally hardware) designed for educational purposes using a computer.  Examples: this helpfile, "Where in the World is Carmen Sandiego?", hypertext systems, animated computer video.  Synonymous with computer-assisted training (CAT).

See also: hypertext, interactive


CGA
Computer Graphics Adapter (CGA)

Describes both the type of circuit board  or video card needed for CGA compatibility, and the type of software emulation needed to view it.  Few colors, low resolution, obsolete.

See also: emulation, Hercules, EGA, VGA, printed circuit board


CIB
computer-integrated business (CIB)

Business having all functions integrated through a common database.

See also: integrate, database


CIM
Computer Integrated Manufacturing (CIM)

Common databasing of all manufacturing-related information.

See also: integrate, SME, numerical control (NC)


computer vision syndrome
computer vision syndrome (CVS)

A disorder common to people who work over long periods with computers and video display terminals (VDT's).  It is characterized by headaches, blurred vision or reduced color sensitivity, double vision, "shadowing" of colors and other visual anomalies.  This is usually a temporary disorder which can be treated in most cases by reduced exposure to CRT displays, a change in the lighting of the work area or a reduction in the brilliance or contrast of the display used by the individual.  Workplace ergonomics experts suggest that computer monitors should be no brighter and have no more contrast than a sheet of printed paper held up next to the monitor, and that backlighting (light reflected from the back of the monitor) should make up 50 percent of the total lighting for the work area.

One of the most common warnings of CVS or impending CVS is a tendency to see mental pictures of a computer screen or computer graphics in dreams or prior to falling asleep.

See also: ergonomics, repetitive strain injury (RSI), CRT


CARIC
Computerized Automation and Robotics Information Center (CARIC)

SME phone access reference library for manufacturing processes and applications.

See also: robotics, SME


concatenate

A term generally used in programming in place of "join".  Concatenating files or strings of data or text is the process of joining them together in sequence.  A fifty-cent word often used in documentation for programs where simpler terms would be more appropriate.


CONFIG.SYS

A file used on DOS-compatible personal computers to  to configure system and software settings and parameters at boot-up, mainly concerning hardware/software interfacing.

See also: AUTOEXEC.BAT, parameter, disk operating system (DOS)


connectivity

Generally refers to the ability of machines or computers to connect to other machines or computers or the state of such a connection.  Connectivity can also refer to the ability to connect or state of connection between the user and the machine or computer.

See also: interface


console

The operator's station of a mainframe computer.  Unlike a terminal, a console allows direct manipulation of the contents of the computer.

Also: the combination of screen and keyboard on a PC.

See also: terminal, mainframe


context, context menu
context, context-sensitive, context menu

Terms used in a wide range of circumstances to refer to the situation involved.

For example, context-sensitive help refers to a help tool that opens topics depending on where you are in the program, so that pressing the F1 key or help button always shows you the help associated with the particular part of the program you are working in.

Context menus are similar, in that they offer you a list of menu choices depending on where you are in a particular program, but it's important to make a distinction here.  True context menus in Windows are activated by holding the mouse cursor over a certain area of the screen and clicking the right mouse button, while context-sensitive menus are menus that change depending on the part of the program you're working in.

See also: syntax, menu, cursor


context sensitive

Used to refer to any computing environment in which the display changes dynamically depending on how the environment is used.  Windows uses context-sensitive menus for many programs.  These menus change depending on what aspect of the program you are working with.  Windows Help is also context sensitive in many cases, allowing the user to use the same F1 or Help command to access help about the specific area of the program they are working with, without having to search for the information.

See also: context menu


contiguous

Adjacent.  Usually refers to the arrangement of data clusters on a hard disk that make up a file.  Discontiguous files take longer to access because data must be accessed from more than one section of the hard disk.

See also: fragmentation, defragment, cluster, hard disk


Control+Alt+Delete, three-fingered salute

Any time a Windows or DOS program stops responding and the system has become unusable, the usual procedure is to press these three keys.  In DOS, this will automatically force a warm boot of the system.  In Windows, this will bring up a dialog offering you the choice to wait for a change in the system or press these three keys to reboot the system.

See also: warm boot


control codes

Control codes are special commands or formatting instructions for a printer, file or modem, such as commands for stopping transmission of a file via modem, creating a carriage return in a textfile, or a page break in a printed file.  The term comes from early PCs when such commands had to be entered manually, usually by pressing the Ctrl key and another key together.

See also: format, carriage return, embedded command, escape sequence


control menu

The menu with options for manipulating windows which most Windows programs make available to you.  The control menu is activated in Windows 3.1/3.11 by clicking the small square in the top left-hand corner of the current window (the control menu box).  In Windows 95, a tiny icon appears in the top left corner to activate the control menu.  This menu usually allows you to Restore, Move, Size, Miinimize, Maximize or Close the current window.  Many programs offer other options from the control menu.

See also: restore, minimize


Control Program for Microcomputers (CP/M)

An early microcomputer operating system written by hacker Gary Kildall for 8080- and Z80-based machines, very popular in the late 1970s but virtually wiped out by MS-DOS after the release of the IBM PC in 1981.  Legend has it that Kildall's company blew its chance to write the OS for the IBM PC because Kildall decided to spend a day IBM's reps wanted to meet with him enjoying the perfect flying weather in his private plane.  Many of CP/M's features and conventions strongly resemble those of early DEC operating systems such as TOPS-10, OS/8, RSTS, and RSX-11.  [Source: The Jargon File 3.0.0]

See also: hacker, operating system, CP/M, Digital Equipment Corp. (DEC)


conventional memory

Intel 8086 and 8088 microprocessor chips can address a maximum of 1024K physical memory, and this limit was set as the upper limit of conventional memory for IBM-compatibles.  The lower 640k is designed specifically for use by DOS.  The remaining 384K is intended to be used for hardware configuration and temporary data buffers, but it is just as often used as a place to store device drivers and memory-resident programs as a means of freeing up more of the first 640K for running DOS programs.

See also: 8088, 8086, memory, Expanded Memory Specification (EMS), extended memory (XMS), upper memory area (UMA), memory resident, device driver


convergence

Refers to the ability of a color picture tube's three electron guns to focus the three colored beams on a single point on the screen.  Poor convergence distorts colors and makes images appear fuzzy, increasing visual stress.  Only correctible using internal adjustments on most monitors, which makes adjusting convergence a dangerous and potentially lethal proposition for most users, since voltages in monitor circuits can be as high as 600 volts.

See also: computer vision syndrome


copyleft

The copyright notice used by GNU and other Free Software Foundation software.  It permits free and complete reuse and reproduction rights to all users without cost, but also contains some cryptic and often misunderstood terminology that many interpreted to mean that anyone distributing GNU software or anything based on GNU code must also distribute the code to all users whether they had a need or desire for it or not.  This led to the GNU public license being referred to in some circles as the "GNU public virus".

See also: Free Software Foundation (FSF)


copy protection

A method of encoding data so that it cannot be duplicated as a method of preventing unauthorized use of the software.  Considered by most experienced users as a troublesome and often stupid method of maximizing revenues to software producers, as the vast majority of users of unlicensed software would not or could not pay for the software whether it was protected or not.

See also: key disk, dongle


core, core dump

Core is synonymous with RAM.  Dates from the days of ferrite-core memory; now archaic but still used on occasion, in particular to signify printouts of the contents of memory to printer, screen or disk ("core dumps").

See also: dump, random access memory (RAM)


Core Wars

A game between assembly language programs in a simulated machine, where the objective is to kill your opponent's program by overwriting it.  Popularized by A. K. Dewdney's column in "Scientific American" magazine, this was actually devised by Victor Vyssotsky, Robert Morris Sr., and Dennis Ritchie in the early 1960s.  Their original game was called Darwin and ran on a PDP-1 at Bell Labs).  [Source: The Jargon File 3.0.0]

Core Wars survives as a popular teaching tool for various languages (versions exist for Pascal, Modula and other languages) and available in many guises on different platforms.

See also: core, Pascal, Modula


COS

Corporation For Open Systems; also, mathematical (programming): cosine.


CPI

Characters per inch: printing format parameter that determines font size of a printout

Also: Computer To PBX Interface: a DEC device capable of 24 communication channels per link with a 750 ft. range)

Also: code page information; relates to key mappings and font layout for foreign-language displays on PCs.  The "code page" is the area of memory, usually about 4K, that contains this information.

See also: parameter, Digital Equipment Corp. (DEC)


CRS

Cursor select, a special key used on some terminals.  In host sessions, this key chooses the data fields for processing.

Also: Canada Remote Systems: a large Canadian online service provider)

See also: terminal


crash
crash, crash recovery

A sudden, usually drastic failure of a program, operating system or piece of computer hardware.

Crash recovery refers either to the act of recovering from a crash or the facilities of a particular piece of software or hardware for dealing with a crash.  For example, Windows 95 offers enhanced crash recovery over Windows 3.1 because it often allows the user to save data in their program before closing a program which has crashed an area of memory.

See also: bomb, operating system, General Protection Fault


Cray
Cray Research

Cray is considered synonymous with supercomputer, but specifically refers to computers made by Cray Research, a company co-founded by Seymour Cray, a noted computer designer.  Legendary for both their unequalled power (they are usually the computer of choice for high-end applications where raw power is the watchword and cost is no object; Cray's typically start at $250,000 for low-end units) and for the exploits, real and rumored, of Cray's co-founder.

See also: supercomputer


Creative Labs, Inc. Sound Blaster
Creative Labs Inc., Sound Blaster

Manufactured by Creative Labs, the Sound Blaster set the standard for digital sound on the IBM-compatible, and despite its Yamaha-licensed FM synthesis being almost a decate behind modern synthesis methods, it continues to be the standard which other manufacturers must meet when developing for the IBM-compatible.  Sound Blaster peripheral cards provide the ability to use CD-ROM drives as players for music CDs, recording and playback of digitized sound samples, internal (and, on some models, external) MIDI music compatibility and a built-in synthesizer capable of FM-type synthesis.

See also: synthesis, sample, IBM-compatible, musical instrument digital interface (MIDI)


crippleware

Software or hardware that has some important functionality deliberately removed, so as to entice potential users to pay for a working version, or which has been deliberately crippled, and can be upgraded to a more expensive model by a trivial change (e.g., cutting a jumper or connecting a cable).

Crippleware usually refers to fully-functional software distributed freely which cannot have all of its features activated until the user pays for a license and receives a serial number designed to activate the crippled features.  Loosely speaking, PC/Internet Lexicon could be termed crippleware.

See the extended topic for some examples of crippleware.

See also: jumper, 486, math coprocessor, heat sink, upgrade


An excellent example of crippleware is Intel's 486SX chip, which is a standard 486DX chip with the co-processor dyked out (in some early versions it was present but disabled).  To upgrade, you buy a complete 486DX chip with working co-processor (its identity thinly veiled by a different pinout) and plug it into the board's expansion socket.  It then disables the SX, which becomes a fancy power sink.  Don't you love Intel?  [Source: The Jargon File 3.0.0]

Another famous crippleware story concerns a Canadian manufacturer who supplied computers in the late 1970s with single hard disks.  An additional hard disk cost another $5,000 at the time.  When the upgrade fee was paid, a factory technician was sent to the site to open the computer's case and plug in the second hard disk which was already sitting -- ready to run and unused -- inside the computer's case.


crlf

A carriage return followed by a line feed.  Both characters are required to create proper "line breaks" on IBM-compatibles, while only the line feed character is needed with UNIX.

See also: UNIX, carriage return, IBM-compatible


crunch

Process, as in "numbers crunching" (numbers processing)


CULPRIT

A lesser-known programming language


cursor

Strictly speaking, it's the horizontal or vertical line (or, in some DOS and Windows programs, the vertical block) that indicates the current "focus" or active location of the screen where text may be entered, commands may be given or menu items typed in.  The mouse arrow is also considered to be a cursor.

See also: caret, menu


CV

Abbreviation for ComputerVision: major manufacturer of CAD/CAM systems, not to be confused with CVS (computer vision syndrome)

See also: CAD/CAM


cybernetics

Strictly speaking, cybernetics is the study of comparative machine functions and natural living processes.  It is the core scientific discipline behind robotics and artificial intelligence.

See also: neural network, robotics, artificial intelligence


cyberpunk

Believed to have been coined either science fiction writer Bruce Bethke and/or editor Gardner Dozois A subgenre of science fiction launched in 1982 by William Gibson's epoch-making novel "Neuromancer", although its roots go back through Vernor Vinge's "True Names" Gibson's near-total ignorance of computers and the present-day hacker culture enabled him to speculate about the role of computers and hackers in the future in ways hackers have since found both irritatingly naive and tremendously stimulating.  Gibson's work was widely imitated, in particular by the short-lived but innovative "Max Headroom" TV series.

Also, cultural: Since 1990 or so, popular culture has included a movement or fashion trend that calls itself cyberpunk, associated especially with the rave/techno subculture.  More attitude than substance according to most cognoscenti.  [Source: The Jargon File 3.0.0]

See also: cyberspace, hacker, virtual reality


cyberspace

Several related meanings: any simulated environment involving two or more people in different geographical locations.

Also: the entire computer cosmosphere including Internet, video games and any other environment which synthesizes or simulates reality or an alternate reality.

Also: the void into which lost data disappears, most frequently used to refer to the final resting place for lost email and news.

Also: a totally synthetic/virtual reality experience as proposed by many science fiction writers.

See also: virtual reality, bit bucket


cycle

The basic unit of computation.  One can describe an instruction as taking so many "clock cycles".  Often the computer can access its memory once on every clock cycle, and so one speaks also of "memory cycles".  [Source: The Jargon File 3.0.0]

See also: memory, system clock, memory


CPS
cycles per second (CPS)

Refers to operating frequency of computer buses (how many times data cycles through the specific part of the system, not just the CPU); also Characters Per Second (easurement of transmission speed of data [characters are bytes of data]; usually refers to modem transmission or printer output.

See also: bus, central processing unit (CPU), modem, cycle


cyclic redundancy check (CRC)

A number derived from a set of data that will be transmitted.  By recalculating the CRC at the remote end and comparing it to the value originally transmitted, the receiving node can detect some types of transmission errors.  [Source: MALAMUD]  CRCs are also used on stand-alone computers to check the integrity of individual files, usually as a method of virus detection.

See also: CRC, checksum, virus


cylinder

A cylinder is a "ring" of data on a hard disk.  Hard disks can have hundreds of tracks, which are magnetic regions similar to the rings seen in the cross-section of a tree trunk.  Hard disks may use several stacked metal platters, not just a single disk, and a cylinder refers to all tracks in the same location on all platters in the hard disk.

See also: track, sector, cluster, hard disk, platter


daisy chain

Usually refers to a method of connecting peripheral devices such as hard disks, in which a the cable runs from the first device to the second, from the second to the third, and so on, rather than having all devices connected to the same central device.  The disadvantage of daisy chaining is that there can be timing delays in the system if the basic architecture of the system is not configured with this possibility in mind.  MIDI is one type of daisy chaining technology that suffers from such a problem.

See also: MIDI, SCSI


daisy wheel
daisy wheel printer

So named because the print head looks like a flower, a daisy wheel is a disk with several dozen flanges, each having a letter or other character at its tip, which is used by a printer or electronic typewriter to print fully-formed characters, rather than series of dots as used by dot-matrix printers.  Daisy wheel printers are still used for creating high-quality, high-volume text-only printouts (they cannot do graphics) in situations where laser printers are not suitable or too expensive for the task, such as the printing of multipart forms.  Being impact printers, daisy wheel printers can make impressions on several sheets at once although dot matrix printers are often more suited to this task.

See also: inkjet printer, laser printer, dot matrix printer


database

A structured collection of information, usually on a related subject, maintained as a unified whole which may be accessed in a variety of ways by the user.

See also: database management system (DBMS), table Structured Query Language (SQL), dBASE/xBase, ORACLE


DBMS
database management system (DBMS)

The software builds and manages database information.  Examples of PC DBMS' are Microsoft Access, Borland Paradox and Ashton-Tate dBASE.

See also: database Structured Query Language (SQL), dBASE/xBase, ORACLE, spreadsheet


Data compression

Data compression is the process of reducing the storage requirements of data through the use of algorithms and mathematical formulae while still leaving the data useful.  Compressed data is uncompressed using software designed for the task when the data is needed by the system.

Data compression is used primarily to reduce disk space requirements for data so that it can be archived in less physical space, but more recently the growth of the Internet has made reduced transmission time at least as important.

Two classes of compression

There are two basic classes of data compression: lossy and lossless.  Lossy compression reduces the level of detail in the data being compressed and provides no facility for restoring that lost detail at a later date.  It is used primarily with audio and video data where some loss of detail can be tolerated for the sake of reduced space requirement or transmission time.  JPEG, GIF and MPEG are examples of lossy compression.

Lossless compression stores all information about the data being compressed so that it can be restored to its complete, unaltered original form at a later date.  PKZIP, Doublespace/Stacker and compressed backup sets are examples of lossless compression.

Several types of compression

Compression can either be performed on individual files, multiple files (also known as archiving) or whole areas of a disk or other storage medium (also known as disk compression).

Data compression often refers to a method of compressing data for transmission over telecommunications circuits such as modems.  Most modems have data compression software encoded directly into their chips, and the use of this software, which is usually recommended for modem communications, allows modems to send and receive data at much higher than their advertised baud rate.  Using data compression, a 28.8kbaud modem can send and receive even files which have already been compressed at a rate of up to 35 kbaud, and send and receive text at up to 115kbaud.

See also: archive, disk compression, Stacker, algorithm, JPEG, MPEG, Graphics Interchange Format (GIF), PKZIP


data file

Strictly speaking, any file on a computer is a data file.  Practically, however, data file is usually reserved to describe any file on a computer which is not an actual program or executable code.

See also: file, program


daughterboard

Circuit board which attaches to the motherboard of a computer to either enhance the computer's functionality or add new capabilities to it.  Daughterboards can either be extensions of the main circuit board or cards for connecting peripheral devices.

See also: motherboard, printed circuit board, peripheral card


DCA

Digital Communications Association

Also: Document Content Architecture: description of hierarchy and structure of document contents (IBM's word processing definition architecture)

Also: Digitally-Controlled Amplifier, a signal amplifier that acts on a digital waveform before it is converted into an analog signal that can be transmitted through a speaker or monitor.  Multiple DCAs are used on synthesizers and sound cards.


DCF

Document Composition Facility

Also: Disk Copy Fast: an extremely popular IBM-compatible floppy disk copy program

Also: Digitally-Controlled Filter: a type of signal modifier used on audio and video signals to alter them prior to conversion into an analog signal that can be transmitted through a speaker or monitor.

See also: document, IBM-compatible


DCLASS

Decision Classification Information System: Brigham-Young University's hierarchical information tree storage and retrieval system.

See also: database


debug

The act of tracing and correcting errors or unwanted output in a process or program.

Also: DEBUG.EXE, a DOS program designed for accessing the operating system, programs and hardware directly from the command line for purposes of alteration and investigation.  Specialized programs designed for this purpose are also referred to as debuggers.

See also: bug, operating system, command prompt


default

In a situation where more than one option is available, any option which is preselected is known as a default.


defragment

Over time, files which are changed or added to, or data which is added to the system, becomes fragmented, meaning that files may be split into sections spread over several areas of a hard disk.  Accessing a fragmented file takes longer than accessing a contiguous file, or one which is laid out end to end on only one area of the hard disk.  Defragmentation is the process of reorganizing a disk (almost always a hard disk) so that all files are contiguous.  Defragmentation also usually involves reordering directory data so that it sits at the front of the disk where it can be accessed more quickly and with less stress on drive mechanisms, and can also involve moving all files to the front of the disk where they can be accessed with less drive head movement.

Defragmentation is routine maintenance for home and business PCs which should be done at least three times annually to insure that the system runs at peak performance.  Defragmentation can also prolong the useful life of some hard disks by reducing the workload on the drive head mechanisms.

See also: file, contiguous


delimiter

A delimiter is a special, "reserved" character used to denote the beginning and/or the end of a field of data.  Delimiters are used in databases and for purposes of converting one database type to another.  The most commonly used character is a comma, but in systems such as address databases that may require commas, another character such as a tilde (^) may be be used because the delimiter character must not be used in the actual data itself.

See also: record, database


desktop

In a graphical operating environment (GUI) such as Windows or OS/2, the combination of elements that make up the visible display, including windows, icons, background graphics, and any custom features added to the display by the user, are referred to as the desktop.  Virtual desktops are also possible with GUI's, and these permit work areas or display areas which extend off the sides of the visible screen to be included in the activities performed by the system.

See also: graphical user interface (GUI), OS/2, icon, virtual


desktop publishing (DTP)

A generic term used to refer to any kind of word processing or document formatting work designed for publication which can be done practically on a desktop.  Typing a newsletter on a manual typewriter for a local club is DTP, as is developing a popular international publication for consumer use on a high-end PC or workstation.

See also: word processor, document, format, thumbnail


device contention

Refers to the way two hardware devices might "contend" for the same IRQ and the way Windows handles this competition.  When two devices request the same IRQ, Windows assigns a higher priority to one or the other device, usually based on a setting defined by the user.  Without the ability to assign priorities, both devices may try to access the same IRQ at the same time and totally freeze the system.

See also: IRQ, IRQ conflict, peripheral device


device driver

These are programs (DOS or Windows) which enable a specific piece of hardware to communicate with the operating system.  Without a device driver installed and running in active memory, the software cannot communicate with the hardware device.  Many standard device drivers are included directly with the operating system on older operating systems such as DOS and Windows 3.1; Windows 95 has its own unique device drivers for virtually every part of the hardware including the floppy disks.

See also: upper memory area (UMA), operating system


DIF
Device Input Format (DIF)

A once-popular type of graphical file format seldom used any more.

See also: Tagged Image File Format (TIFF), Graphics Interchange Format (GIF), JPEG, PNG


Dhrystones

A standard unit of measurement of a computer's operational speed in processes not involving floating-point mathematical operations Originally developed in 1984 to test the performance of Ada programs under various conditions, it is now used as a general benchmarking test for hardware performance in many diagnostics packages.

See also: Whetstones, MIPS, MFLOPS, benchmark


dialog box

Simply put, a box that carries on a dialog with the user.  A term used mainly with Windows but also relevant to DOS.  Dialog boxes can be as simple as a box that pops up and says "Touch your toes and press OK when you're done" or as complex as the File Open and File Save dialog boxes used by many Windows programs.

See also: common dialog


digital

Any thing or event which is expressible in terms of integers or fixed states; i.e. 0's and 1's, on/off.

See also: binary, analog


Digital Audio Tape (DAT)

A type of cassette tape storage system that stores binary information rather than variable analog signals.  Because binary information is absolute (it's either a 1 or a 0, not something in between) DAT is ideal for storing large amounts of information in a small space such as audio data, the purpose for which it is most used.

DAT is also used for tape backup in some situations.  One DAT cassette can store 1.3 gigabytes of data, the equivalent of two CDs.

See also: backup, binary, tape backup unit, CD


DDL
digital delay line (DDL)

A DDL uses memory to store information and delay its output; used to time processes properly, most popularly known for the audio echo effects it creates with live or recorded music.

See also: digital-to-analog converter, analog-to-digital converter


DEC
Digital Equipment Corporation (DEC)

American high-tech giant primarily known as a manufacturer of high-end business computer systems used in networks.  DEC has been responsible for a large number of computing firsts over several decades, including the legendary PDP-series minicomputers on which an enormous number of important computing developments first appeared.

See also: minicomputer, PDP-x


DRI
Digital Research Incorporated (DRI)

Manufacturers of DR-DOS and GEM.

(See also: DR-DOS, GEM, Atari


DSP
digital signal processing (DSP)

DSP chips take the load off the CPU by performing calculations on data before passing instructions on to the CPU.  They are also programmable, meaning that a DSP can be instructed by software to perform any or many of several tasks at once.  This makes possible devices such as video interface cards which are also TV tuners, sound cards which act as answering machines and recording devices, and effects modules whose tasks can be altered at the whim of the operator.

See also: central processing unit (CPU), interface, multitasking


DAC
digital-to-analog converter (DAC)

A device used to convert signals such as CD binary data into analog signal such as pre-amplified sound; used in virtually all consumer-level computer-based products.

See also: CD, analog-to-digital converter


Digital Video Interactive (DVI)
Digital Video Interactive (DVI), Indeo

This technology combines moving and still pictures, audio and graphics and permits interaction with the system.  Conceived by Larry Ryan of the David Sarnoff Research Center (RCA Laboratories) in 1983 and developed by General Electric, Intel now produces the DVI technology.  Optimum performance requires an actual DVI board in the computer.

The software version of DVI is known as Indeo, and it is included with many video-based Windows products as a means of accessing DVI video without the actual hardware.

See also: CD-I, MCI


digitizing tablet

A tablet is a hardware device used mainly in graphic design and CAD applications.  It consists of a flat surface which is used as a drawing area, and the user can either use it to trace drawings laid on the tablet's surface and have them appear on the screen, or draw directly onto the tablet rather than using a mouse.  Far more precise and comfortable than a mouse in most cases, although younger users who have grown up with mice from an early age do not seem to have the same dependence on a tablet as older users raised on flat paper drawing.

See also: scanner, TWAIN, CAD


dingbat

A graphical character meant to be used as a decorative item or attention-getter or bullet in word processing and desktop publishing.  Dingbats are usually of a similar size to the text they are set next to.  Dingbat fonts are available on most operating systems; the most popular Windows dingbat font is known as Wingdings.

See also: font, bullet, word processing, desktop publishing


DASD
direct access storage device (DASD)

Permanent memory storage area, usually magnetic tape or disk.

See also: mag tape


DMA
direct memory access (DMA)

A type of computer controller, usually a dedicated chip.  These chips help to distribute functions to activities such as reading/writing to disk and ports rather than routing all information directly through the CPU.

See also: central processing unit (CPU), memory


directory (folder)

Directories technically don't exist in real terms on your hard disk.  There is no fixed amount of space designed to hold files.  Instead, a directory is a data block which is used to allows files to be grouped together under a common heading for easy search and retrieval, and when directories are shown on the disk they appear to be specific data areas because the directory/folder model is a model most users can understand.  On Macintosh's, Atari's and more recently, in Windows 95, directories are commonly referred to as folders.  Windows veterans have been slow to adopt this new convention, choosing instead to reserve folder for the name of the mini-icon that represents a directory.  For all practical purposes though, folder and directory are now interchangeable.

See also: file, directory structure, working directory, file allocation table, Macintosh, Atari


directory structure (directory tree)
directory tree structure (directory tree)

Term used to describe the way directories and files are laid out on a specific disk.  (Tree structure refers to the way files are laid out on all IBM-compatibles.)

See also: tree, branch, root, expand, collapse


dirty power

Electrical current containing spikes, drop-outs, average voltage significantly higher or lower than normal, and line noise (interference in the basic pulse of AC electrical current), all of which contribute to erratic performance or hazardous operating conditions in a computer or other electrical device.  Particularly problematical in areas with antiquated electrical trunks and industrial environments which maintain on-site generation and/or create substantial electromagnetic fields.

See also: line surge, power conditioner, uninterruptible power supply


disk cache

A disk cache is sleight-of-hand software designed to speed up a system's performance.  It stores information in a reserved area of RAM memory prior to writing to the floppy or hard disk, allowing the system to remain in use until there is enough of a break in the action for the cache to "flush" its information to the disk or device specified.  The most common disk cache is SMARTDRV.EXE used with DOS and Windows, and it provides a dramatic improvement in overall system performance when used with disk-intensive applications.

Disk caches can also be used to read data in advance of need to provide still more improvement in performance.  CD-ROM drives in particular benefit from this type of disk caching.

See also: read-ahead, random access memory (RAM), buffer


disk compression

A type of data compression designed to increase the usable storage space on a floppy disk (but usually used only on hard disks) by turning the entire disk or a large section of it into a single compressed file.  Disk compression runs transparently, meaning that the user never sees it operating other than during routine disk maintenance.

Disk compression can increase the usable storage space on a hard disk by up to two times, but at a cost.  The file compression usually results in slower overall system performance and any additional processing on a hard disk reduces its reliability no matter how bulletproof the programming might be.

STAC Electronics' Stacker and Microsoft's DoubleSpace and DriveSpace are the two most commonly used disk compression software on the PC.

See also: data compression, Stacker, bulletproof


DOS
disk operating system (DOS)

Refers to any such system, not necessarily the IBM-compatible DOS', although it is generally used to indicate IBM, Novell or Microsoft's general-purpose, low function, disk memory oriented operating system.  Has come to be synonymous with MS-DOS, or Microsoft DOS, the product that built the Redmond, Washington software giant into the world's largest software publisher.

See also: operating system, Microsoft, IBM-compatible


DISSOS

Distributed Office Systems: a framework for integrating multiple workstations and office systems.

See also: integrate, network


DM

Delta modulation


DMF

Data Manager Function: IBM PACS disk/storage resident data structures and organizations

Also: Distribution Media Format: a floppy disk format that allows 1.44Mb 3.5" disks to be filled with 1.68Mb of data for purposes of more efficient distribution.  The floppy disk version of Windows 95 uses the DMF format.

See also: format, floppy disk


document

Although document originally referred to actual printable documents using text or formatted text, document has more recently become synonymous with a data file - any data file - created by an application.

See also: data file, application, document window


document window, application window

Most graphical operating systems that use windows have two types of windows: an application window and a document window.  The application window is like the "shell" window which holds all other windows used in the program.  Any program capable of loading more than two files at once and allowing you to switch between them uses what are known as document windows.  These document windows cannot overlap onto the desktop; they must be completely contained within the application window.

See also: document, application, shell, graphical user interface (GUI)


dongle, dongle disk

A piece of hardware security or a copy protection device designed to prevent unauthorized use of a piece of software.  This device is usually a packaged IC which is supplied with the software and must be connected to the computer while the program is running.  Despised by most users due to their tendency to interfere with other software and make life difficult, particularly for owners of multiple computers needing to use the same program on both a desktop and laptop computer.

Can also refer to a key disk.

See also: key disk, copy protection

Trivia

In early 1992, advertising copy from Rainbow Technologies (a manufacturer of dongles) included a claim that the word derived from "Don Gall", allegedly the inventor of the device.  The company's receptionist will cheerfully tell you that the story is a myth invented for the ad copy.  Nevertheless, I expect it to haunt my life as a lexicographer for at least the next ten years. --- ESR] [Trivial source: The Jargon File 3.0.0]


Doom, Wolfenstein

Two breakthrough games from shareware games producers ID Software (formerly associated with Apogee) which used revolutionary 3-D virtual perspectives and unparalleled violence and gore for a widely available computer game.  Castle Wolfenstein, known to most simply as Wolfenstein, set the standard which Doom surpassed and reset, and turned ID into the single most successful shareware publishing house in history.  Probably the two most popular video games released since Pacman and Donkey Kong, and perhaps the most popular ever.  Both have been cited on numerous occasions as factors in firings, divorce suits, negligence actions and software censorship and content labelling discussions.

See also: virtual reality


DOS Protected Mode Interface (DPMI)

A method of memory management that allows multiple programs, or multiple processes within a single program, to run safely in DOS (a single-tasking operating system) without crashing the whole system if one process develops a fault.  It allows the system to effectively multitask DOS programs using extended memory, and - where necessary or useful - the hard disk as a swapfile for access to virtual memory.  DPMI is the industry standard specification followed by programs wishing to make use of these features, and all PCs except those with the earliest 8088 processors can take advantage of it.  Popular programs which make use of DPMI are PKZIP/PKUNZIP and many arcade-style games.

See also: extended memory, multitasking, virtual memory, protected memory, 8088, text mode/graphics mode


dot matrix printer

The most common type of personal computer printer until about 1994.  Dot matrix printers are characterized by a print head made up of usually nine or 24 pins laid out in a matrix.  The pressure of some or all of these pins on a typewriter-style film ribbon makes the impression on the paper and produces the printout.  Dot matrix printers are notorious for being slower and much noisier than inkjet and laser printers but have the benefits of high reliability, low cost, the ability to print multi-part forms, and ease of maintenance. It is not uncommon for dot matrix printers to be used daily for five years or longer in a clean environment and require nothing except the occasional ribbon change.

Dot matrix printers are a type of device known as an impact printer because the pins must impact the ribbon onto the paper to produce a visible result.  They differ in functionality from daisy wheel printers, which create much crisper text, in their ability to print graphics.

See also: inkjet printer, laser printer, daisy wheel printer


dot pitch

The amount of space between the dots, or small windows, of phosphor at the front of a picture tube.  A .28mm dot pitch means that there are .28 millimetres of unused space between each dot on the screen.

See also: resolution


double-click

Double-clicking refers to the act of pressing an releasing a mouse button twice in rapid succession.  The computer is usually designed to respond in one way to a single click and another way if it sees a second click soon after the first.  Double-clicking is almost always used to launch a document or program, while single-clicking merely selects the item for some other action.

See also: launch


double-density
double-density, high density, DS/DD, DS/HD, SS/DD

The three surviving floppy drive density identifications common to IBM-compatible computers, soon to become two since single-sided double-density (SS/DD) is almost never used now that double-sided drives can be purchased used for as little as $5.00.

The density refers to the amount of data that can be packed onto the surface of the disk.  Floppy disks originally started out as single-sided, single-density disks since the recording media and heads had a tendency to "bleed" onto nearby tracks and could not reliably write on both sides of a disk.  Eight-inch floppies originally allowed only forty tracks of data; modern 3.5" floppies allow up to 82 tracks on both sides of the disk thanks to improvements in the precision of disk drives, reduced costs for two-head floppy drives and improvements in the magnetic media used in manufacturing the disks.

DS/HD stands for high density, which allows up to twenty sectors per track over the usual nine or ten on a 3.5" floppy.

The same acronyms are used to describe format and density for 5.25" disks as well, but the storage capacities differ on these disks.

See also: floppy disk, sector, format


downloadable fonts, softfonts
downloadable font, softfont

Softfonts are literally software fonts which are sent to the printer prior to printing a document.  These differ from hardware fonts in that they can reside on a hard disk and do not need to be included with the printer or on a plug-in font data card designed for the printer.  Usually used with inkjet and laser printers.

See also: laser printer, inkjet printer, font,


drag and drop

Dragging and dropping is the common term for an action carried out by the mouse which involves moving an item, selection or object from one part of the screen to the other.  A drag operation requires the user to click and hold a mouse button while moving the item to the appropriate position on the screen.  When the item is situated in the appropriate location, it is then dropped onto that location by releasing the mouse button.

See also: graphical user interface (GUI), object-oriented interface (OOI)


DR-DOS

Digital Research Inc.'s DOS operating system; had some popularity in the late 1980s but never gained popularity.  Later purchased by Novell and now sold with considerable changes and enhancements as Novell DOS.  Infamous for incompatibility problems.

See also: disk operating system (DOS), Novell, operating system


drop-down menu (pull-down menu)

Drop-down menu and pull-down menu are virtually synonymous.  One of the many types of menus available in Windows and other GUI's.  Drop-down menus are menus which are invisible until a word or item is selected.  When that item is selected, a new list of choices appears to "drop down" from the original choice.  Click File from the top menu bar of this help tool for an example of what a drop-down menu looks like.

See also: menu, graphical user interface (GUI)


DIF
dual inline package, DIP switch

In everyday usage, DIPs are usually thought of collections of several tiny on/off switches mounted on a frame that looks like a computer chip housing.  They are usually designed to be set once to match a device to its host hardware.

Strictly speaking, DIP actually refers to any integrated circuit with two sets of connectors on either side of the chip housing, whether there are four pins or a hundred and four.  Old-style RAM chips are DIPs.  The earliest IBM-compatible CPU's, the 8088 and 8086 chips, also came packaged as DIP ICs.  DIPs are the common centipede-like components most people associate with computer chips.

See also: chip, integrated circuit, 8088/8086, IBM-compatible


dump

When a copy of the contents of a particular file or area of memory is made to another type of storage, this is referred to as a dump.  There are two common types of dumps used.  A screen dump is essentially a copy of the screen's contents saved to a file or sent to the printer.  A memory dump (or core dump) is a copy of the contents of memory or a part of a computer's memory.

See also: screen grabber, core, memory


Dynamic Data Exchange (DDE)

This is a form of information exchange in multitasking operating systems such as Microsoft Windows and OS/2 that allows information and resources to be exchanged between two or more programs that support the protocol.  For example, it's what allows a program such as a word processor to automatically update an address book when an address inserted into a letter document.  Both programs must be configured properly for DDE to function.

See also: Object Linking and Embedding (OLE), OS/2,


dynamic link library (DLL)

A DLL is a collection, or library of code, or instructions, used as an additional resource to a particular program.  DLL's are designed to add functionality to programs which cannot or cannot easily be added to the program file itself.  A significant advantage of DLLs is that they can be used by more than one program.  DOS overlay files were usually written for use by one program and one program only, but the functions in a DLL can be used by any program capable of accessing its functions.

See also: Dynamic Data Exchange  (DDE), Object Linking and Embedding (OLE), overlay


DRAM
dynamic random access memory (DRAM)

This type of memory's contents can change from instant to instant and loses its contents when power is cut off, as opposed to ROM memory which is fixed and unchanging.  For the technically-minded, DRAM uses capacitors as actual memory storage.  DRAM is the standard type of RAM used in personal computers.

DRAM can also refer to the memory chips themselves, especially when discussing chip types.  SIMMs, the type of modules used to package nearly all DRAM today, are rarely referred to by retailers as DRAM; instead, DRAM is used to refer to the centipede-like DIP memory chips used in older PCs.

See also: random access memory (RAM), static RAM, Non-volatile RAM, SIMM/SIPP, DIP


Easter egg, egg

Usually refers to a message hidden in a program by the programmer or publisher, usually for purposes of ego gratification, which is not accessible using documented commands.  Can include text, graphics and occasionally sound.  Loved by computer addicts due to their arcane nature; hated by industry-watchers due to the tendency of some programmers to hide elaborate eggs which consume inordinately large amounts of disk space for a feature which most users will never know about.  Stems from "Easter egg hunt".  For an example of an Easter egg, type about: Mozilla in Netscape's Location: box.  An Easter egg is also hidden in the Windows Help customization utility available from the Extras button above.

See also: undocumented feature


ECC

Error Checking And Correction


ECMA

European Computer Manufacturers Association


eight-dot-three

Slang term used to refer to the way DOS and Windows named their files prior to Windows 95: using up to eight characters for the file name, a period or dot, and up to three characters for an extension.

See also: naming convention, syntax, extension, LFN


EII

Electronic Industries Institute


EAROM
electrically alterable read-only memory (EAROM)

A type of computer memory combining characteristics of RAM and ROM; permanent but erasable through the application of current to part of the circuit.

See also: random access memory (RAM), read-only memory (ROM)


EMI
electromagnetic interference (EMI)

Stray or unwanted electrical energy within computer circuitry.

See also: extra-low frequency radiation (ELF), radio frequency interference (RFI)


electromagnetism (EM)

When used in context of computing, EM usually refers to electromagnetic radiation, such as that created by power conversion circuits and power lines.  May also refer to specific areas of the EM spectrum.

See also: extra-low frequency radiation (ELF), radio frequency interference (RFI)


EDP
electronic data processing (EDP)

A catch-all term/acronym encompassing the broad field of electronics, computers and related activities.


EIA
Electronic Industries Association (EIA)

Usually refers to NC tape punch format with even parity (8 holes per row on 1" tape, from the days when computer data was stored on punched paper tape)

See also: numerical control (NC)


ELIZA

This term comes from the famous ELIZA program by Joseph Weizenbaum, which simulated a Rogerian psychoanalyst by rephrasing many of the patient's statements as questions and posing them to the patient.  It worked by simple pattern recognition and substitution of key words into canned phrases.  It was so convincing, however, that there are many anecdotes about people becoming very emotionally caught up in dealing with ELIZA.  All this was due to people's tendency to attach to words meanings which the computer never put there.  The ELIZA effect refers to the tendency of humans to attach associations to terms from prior experience.  For example, there is nothing magic about the symbol + that makes it well-suited to indicate addition; it's just that people associate it with addition.  [Source: The Jargon File 3.0.0]

Burned into popular culture by Firesign Theatre, whose "Dr. Memory" computer character on the 1971 album "I Think We're All Bozos on This Bus" was apparently based on FT member David Ossman's experience seeing ELIZA function on a PDP-6 computer in the 1960s.

See also: artificial intelligence, PDP-10, keyword search


EMACS

From Editing MACroS, the loved/despised programmable text editor which contains a complete LISP language, originally written by Richard Stallman at MIT and used mainly by programmers; versions are available on every computer platform.

See also: LISP, MIT, text editor,


embed

Embedding is the process of inserting a file or the contents of a file into another file.  For example, graphics objects in most Windows word processing documents are usually embedded into the document.  An object embedded into a Windows program can usually be edited without exiting the program in which the person is working.  The program used to create the object is called up when the embedded object is double-clicked, and when editing is done the editing is instantly visible in the document that contains the object.

See also: Object Linking and Embedding (OLE), Dynamic Data Exchange  (DDE)


embedded command

Embedded commands are codes (usually control codes used to format the document) which are inserted into a file to control parameters on a hardware device, usually a printer or a plotter.  Embedded commands are used to change a printer's typeface or font size, line length and other characteristics.  Largely obsolete.

See also: escape sequence, control code


emulator, emulation

Emulator is used to refer to any software or hardware which is designed to mimic the function of other hardware or software, particularly when the emulation is of the "they said it couldn't be done" variety.  Emulator usually refers to a program or peripheral card which expands the capabilities of a computer to encompass other computers or operating systems.  Examples of emulators are Mac-in-DOS, a card which allows a Macintosh to perform as if it is a 486DX series IBM-compatible; and Executor, a PC program that allows IBM-compatibles to run Mac software.  Emulators based on software generally do not run at top speed; emulators based on hardware tend to run faster than the devices they are emulating.

Emulation is usually used to refer to the act of mimicking any hardware or software function regardless of the difficulty.  For example, all 386 and higher PCs are easily capable of using onboard memory as expanded memory, but because a separate memory card is not being used, expanded memory created with software memory managers is referred to as expanded memory emulation.

Emulator is not to be confused with the EMUlator, a digital musical sampling instrument used in music and film production.

See also: peripheral card, operating system, Macintosh, memory manager, clean room engineering, sample, IBM-compatible


encryption

Refers to the manipulation of a file or packet's data in order to prevent anyone but the intended recipient from reading or using that data.  There are many types of data encryption, and data encryption comprises the basis of network security.

See also: PKZIP


EOB
end of block (EOB)

Character representing end of line/block of information in NC program tape; still in use in some disk-based operating systems.

See also: disk operating system (DOS), numerical control (NC)


end user

The person you see when you look in the mirror.  Many industry watchers are upset by the use of the term "user" to describe a computer owner.  According to some, it connotes aspects of drug use, and represents a tendency within the industry to treat the consumer as an addict in need of a fix or a better high.

See also: FUD


EGA
Enhanced Graphics Adapter (EGA)

The IBM enhanced PC graphics adapter card was the standard for several years in the mid to late 1980s.  It allowed 256 colors at low resolutions, 16 colors at high resolutions.  Obsolete.  EGA's top end is identical to the Microsoft Windows standard VGA display resolution of 16 colors at 640x480 pixels.

Hacker slang: "Enhanced Graphics Ain't", signifying the disappointment that EGA lagged far behind comparable display resolutions available on other PC platforms.  In spite of the complaints, it was EGA that first gave the IBM-compatible a serious shot at being a true home entertainment center, not just a workhorse.

See also: CGA, VGA, pixel, resolution


Enhanced Integrated Drive Electronics (EIDE, ATA, ATAPI)

Developed by Western Digital, EIDE became the consumer standard for hard disk manufacture in early 1995.  This relatively new standard permits as many as four hard disks up to 8.4Gb in size and also allows the connection of CD-ROM and tape drives to the hard disk controller, Plug-and-Play compatibility and up to 13Mb/sec data transfer rates.  Also less commonly referred to as AT Attachment or ATA Packet Interface.

See also: integrate, CD-ROM, IDE, Plug-and-Play


ESDI
Enhanced Small Device Interface (ESDI)

A standard for devices such as hard disks and video cards that is no longer in popular use.  Expected to be the "next big thing" in high-speed data transfer, it fell flat in the marketplace.

See also: RLL, EISA, IDE, VLB


environment variable

An environment variable is a character or a string of characters inserted into memory by DOS or Windows and used by the operating system as a means of "policing" certain activities.

Environment variables are simple methods of allowing programs to respond to specific situations and let other parts of the system (including the original program) know what is happening.  Environment variables are commonly used to tell DOS and Windows where to store temporary files, which options to turn on or off for hardware devices such as CD-ROM drives and sound cards, and to tell specific programs where to look for needed files.  Environment variables are set using the SET command (for example SET TEMP=C:\TEMP tells DOS and Windows to store temporary files in the C:\TEMP directory when they have no specific location set aside for storage).  The existence or non-existence of specific characters in specific spots in memory can be used by programmers to determine any number of things.  For example, a program might show you a list of files from which you can choose, and "stuff" the name of the file you choose into an environment variable for use later.

See also: temporary file


EOF

End Of Field: refers to the end of a given field of data.

Also: End of File, a character or text abbreviation tagged onto the end of a file to alert some programs to cease processing at this point.


EPA

Extended Performance Architecture (also Environmental Protection Agency [US])


EPROM
erasable, programmable read-only memory (EPROM)

Computer memory which can be erased and reprogrammed with ultraviolet light; allows chips to be reused for various purposes.  Generally expensive.

See also: read-only memory (ROM), random access memory (RAM), chip, EAROM


ergonomics

Strictly speaking, ergonomics is the study of biotechnology.  Practically, ergonomics relates to anything concerning the combination of safety, comfort and productivity of a person in a particular environment.  Ergonomics as it concerns computers has lately become equated with the effort to stem the rising incidence of repetitive strain injury and other afflictions associated with long-term intensive use of a computer through the use of exercise, posture, furnishings and workplace layout.

See also: carpal tunnel syndrome, computer vision syndrome, mouse shoulder, repetitive strain injury (RSI)


errorlevel

Strictly speaking, refers to the level of error produced by a program or command which cannot be executed as requested.  Used in programming to define possible variables.  DOS has 256 errorlevels, meaning that a decision can be made based on any of up to 256 corresponding errors or non-errors.

Errorlevels are usually used in "if/if not" statements in low level languages.  In plain English, a simple menu might say to DOS:

choice Run (1)123.EXE (Lotus), (2)WP.EXE (WordPerfect), (3)XL.EXE, (4)DOOM.EXE, or (5)SCANDISK.EXE? /c:12345  (I want you to look for five specific files.  Return an errorlevel of 1 for the FIRST file, 2 for the SECOND file, and so on.)

if errorlevel 1 if not errorlevel 2 123.EXE  (If the errorlevel is 2, meaning that I pressed 1 and not 2,3,4 or 5, then I want you to start the FIRST program on the menu.)

if errorlevel 2 if not errorlevel 3 WP.EXE  (If I press 2, then return an errorlevel of 2 and start WordPerfect)

…etc.

See also: environment variable, boolean, execution


escape sequence

A sequence of characters designed to perform a certain function from the keyboard (or using a keyboard-like command input method) which cannot be performed directly from the keyboard itself.  An escape character is used to begin and end the sequence of characters, thus leading to the name.

Escape sequences are used with printers for sending control codes (special printer formatting commands) in the middle of documents, and for creating graphical effects on a DOS screen such as colored or flashing text.  In the case of onscreen effects using escape sequences, a special device driver, known as an ANSI driver, must be present in the system to allow the effects to be visible.

See also: American National Standards Institute (ANSI), control codes, device driver, format


ES
ESPROLOG

Extended Self-contained PROLOG: an artificial intelligence development language based on PROLOG.

See also: PROLOG, artificial intelligence


execution, execution time
execution, execution time, executable

Execution refers to the process of carrying out the specific instructions within a program or a specific command entered at the keyboard.

PC Glossary also refers to the term execution time, which can mean either the time required to fetch, decode, and execute an instruction, the specific moment when a program is being executed, or the time it takes for a program to run from start to finish.

Executable is a commonly-used synonym for program or runnable file.

See also: program


expand, EXPAND.EXE

Two meanings.  When navigating directories, expand refers to displaying additional sublevels or branches of the directory tree.  When working with compressed archives, expand is used interchangeable with uncompress to refer to the process of restoring compressed files to their original size and state.

EXPAND.EXE is a program supplied with DOS and Windows designed to expand files processed with COMPRESS.EXE, the program used to reduce the size of files for distribution on Microsoft and many other types of installation disks.

See also: branch, tree, data compression, archive, install


Expanded memory (EMS)

Expanded memory is memory which resides outside of conventional memory but can be mapped into one or more conventional memory areas, using a 64K page "frame" located between the 640K DOS limit and the 1Mb "conventional" limit.  This frame moves 32K (but more commonly 16K) blocks of memory in and out of conventional memory for use by the program, essentially "cheating" the system.

Greater flexibility for slow PCs

Expanded memory was designed to allow older 8088 and 8086 PCs to make use of more than one megabyte of memory.  Extended memory was introduced as a new standard with the 80286 CPU, but EMS stuck around due to its popularity and is still used by many programs, most notably Lotus 1-2-3 for DOS.

The Expanded Memory Specification

The EMS stands for Expanded Memory Specification.  This specification was first set down by a consortium consisting of Lotus, Intel and Microsoft and is still referred to as the LIM-EMS specification.  Early versions used 16K and 32K page frames; the 4.0 spec still in use allows a 64K page frame.

The Enhanced Expanded Memory Specification (EEMS) was refined by Ashton-Tate, AST and Quadram to allow more access to memory than the original specification, which was limited to 32Mb.

Expanded versus extended memory

EMS memory offers the option of configuring some or all of the available memory as additional memory for programs that can make use of it; extended memory uses all available system memory but is also considerably faster than expanded memory.

See also: expanded memory manager, Lotus/Intel/Microsoft (LIM), extended memory (XMS), page, conventional memory


XMA
Expanded Memory Adapter (XMA)

IBM expanded memory function board for 3270-series PC's; obsolete.  These boards were capable of holding additional DRAM for use as expanded memory.

See also: dynamic random-access memory (DRAM), IBM 3270/PC, extended memory (XMS), expanded memory


EMM
expanded memory manager (EMM), EMM386.EXE

DOS device driver software which allows several programs to use expanded page memory in turn.  Allows several programs to be loaded into memory at once, provided all can fit their necessary components into the base 640K of DOS memory.  The EMM installed on most systems is the memory manager included with MS-DOS 5.0 and higher and Windows 3.1 and higher: EMM386.EXE.

See also: QEMM, 386MAX, expanded memory, device driver


expansion slot
expansion slot, edge connector

This is a physical slot on the motherboard of a computer which allows it to accept and adapt to devices made by other manufacturers.  Expansion slots are an essential feature of modern motherboards.  Most computers have between six and eight such slots.  There are several varieties of expansion slots, including 8-bit slots (usually for modems and older components, a holdover from the early days), 16-bit slots, 32-bit EISA or VLB slots, and 64-bit PCI slots.

Edge connectors are the hardware connectors that fit into standard PC expansion slots.  Typically the connector is part of the circuit board itself, and has plated contacts on each side where the card connects with the computer's circuits.  These connectors are very durable and are usually gold-plated for corrosion resistance.

See also: motherboard, daughterboard, peripheral device, IDE, EIDE, EISA, VLB, PCI,bus


EBCDIC
Extended Binary Coded Decimal Interchange Code (EBCDIC)

Originally a tape format using pattern of eight binary bits per character.  EBCDIC is the standard used on mainframe computers and minicomputers, which is why it has found popularity on the Internet.  ASCII is the standard code used on PCs.

See also: ASCII, bit, byte, mainframe, minicomputer


Extended Graphics Array (XGA)

Video standard developed by IBM as the successor to VGA.  One of many graphics standards introduced by IBM which didn't quite make it.

See also: 8514/A, PGA, VGA, UVGA, Texas Instruments Graphic Architecture (TIGA)


Extended Industry Standard Architecture (EISA)

When IBM introduced MicroChannel Architecture as the new standard for peripheral devices for its 80386-based Personal System/2 computers, the industry responded with resounding disinterest.  MCA has the unforgivable shortcoming of not permitting older-style 8-bit and 16-bit ISA devices to be combined with 32-bit MCA devices.

A consortium led by Compaq developed the EISA specification as an alternative for "clone" systems, and for many years it was the de facto 32-bit standard for IBM-compatible peripheral devices.  It was never widely accepted due to its cost, and the availability of inexpensive VESA Local Bus hardware has relegated EISA to the standards boneyard.  MCA, incidentally, still survives and is in use even on newer 486-series IBM PCs.

See also: ISA, bus, peripheral device, clone, 80386, VESA Local Bus, MicroChannel Architecture


extended-level synthesizer

The current standard for sound cards and synthesizers connected to computers, extended-level synths allow a minimum of 16 notes on nine melodic instruments assigned to nine channels, plus 16 notes on eight percussive instruments on one channel simultaneously.  Sound Blaster 16 and compatible cards are all extended-level compatible.

See also: Sound Blaster, base-level synthesizer, synthesizer


extended memory, XMS, HIMEM.SYS

Extended memory refers to all available memory beyond the first megabyte in 80286 and newer computers.  Unlike expanded memory, it cannot be partially allocated; it will use up all memory available, which is usually advantageous in any case.

Extended memory requires a memory manager such as QEMM or HIMEM.SYS included with most brands of DOS.

XMS is extended memory that meets the Extended Memory Specification and is used by a wide range of programs including Windows and  OS/2.  XMS memory is also faster than EMS since it does not need to be "paged" in and out of memory in 64K chunks.  XMS was developed by Lotus, Intel, Microsoft, and AST Research.

See also: expanded memory, page, Lotus/Intel/Microsoft (LIM), QEMM, disk operating system (DOS), 80286, conventional memory, memory manager


extension

Refers to the final characters in a filename after the period.  DOS and Windows prior to Windows 95 were limited to filenames of up to eleven characters, up to eight of which appeared before the period and up to three of which appeared after.  The characters after the period, or dot, are referred to as the extension and are usually used to indicate what the file is used for.

For example, plain text files without special formatting usually have .TXT extensions.  Programs have .EXE extensions, and in DOS can also have .COM extensions.  File extensions are used as an organizational tool, and in Windows to help the operating systems automatically load certain types of files into their related programs.

Windows 95 no longer limits files to eleven characters but still makes use of three-character file extensions for auto-loading documents.

See also: associate, eight-dot-three, document


external, internal cache

These are types of cache memory.  External and internal relate to the location of this memory hardware in relation to the CPU.  External caches are usually chips or modules located on the motherboard; internal caches are located within the CPU's housing itself.  Most internal caches are 16K or less; external caches tend to range from 64K to 256K in size; the smaller sized caches being used on 80386 motherboards and the larger sizes on fast 486 and Pentium machines.  Most well-configured systems give video and BIOS routines priority access to the cache.

Internal caches cannot be increased in size, although they can be disabled.  External caches can be increased in size in many cases, although in most cases the motherboard comes optimally preconfigured with a specific amount of cache memory.

Internal and external cache memory operate at many times the speed of normal DRAM, unlike software caches which use reserved areas of DRAM.

See also: cache, memory, central processing unit (CPU), motherboard, static RAM, dynamic random access memory (DRAM), BIOS


extract

Although it can have a number of fairly obvious meanings,  it most often refers to the process of uncompressing files contained within a compressed archive file, such as an individual file in a backup tape or disk set, or uncompressing files in a compressed archive file obtained from a BBS, online service or Internet site.

See also: data compression, archive, pack/unpack, backup, tape backup, Internet


ELF
extremely low frequency electromagnetic radiation (ELF)

Electrical lines pulsing at 45 or 60 cycles per second are an example of ELF radiation. also the Earth has its own pulse of about six cycles per second.  Used in context of measuring radiation and interference in electrical circuits, particularly computer monitors and power lines; also in ergonomics and workplace safety.

Although there has been considerable debate over whether ELF radiation poses any threat to public health and safety, the World Health Organization has been quite clear about their position on the matter:

"Exposure to ELF (extremely low frequency) electric fields can alter cellular physiological and behavioral events...At present, studies serve as a warning that unnecessary  exposure to electric fields should be avoided.

"It is recommended that efforts be made to limit exposure, particularly for members of the general population, to levels as low as can be reasonably achieved."

- Environmental Health Criteria: 35, Extremely Low Frequency (ELF) Fields, World Health Organization, Geneva, 1984, pp. 18 and 88. -

See also: electromagnetic radiation (EM), radio frequency interference (RFI), MPR II


facsimile (FAX)

An ancient form of communication in computing terms, traceable to 1842 when Scottish inventor Alexander Bain developed a machine for transmitting simple images over short-distance telephone connections.  Facsimile transmission is, as it might seem, transmission of a facsimile of the original document over a phone line or other networked data connection.

Most modern FAX transfer is done with stand-alone FAX units which are essentially baby photocopiers.  They include scanners for creating digital images of the documents to be transmitted and printing facilities for creating hard copies of the documents received.

This trend is expected to be reversed by the end of 1996 as virtually all new modems come equipped with facilities for sending and receiving FAX and more and more document processing is being done on computers rather than by hand or with typewriters.

See also: scanner, FAX/modem


Fairchild

Usually used to refer to the Fairchild Instruments Palo Alto development group.  Fairchild Instruments is an American high-tech firm better known in 1960s and 1970s for the manufacture of mainframes and high-end business and military computers, and now an aerospace giant.

See also: mainframe


FASST

An as-yet little-used specification that allows easy interfacing of hardware devices with different operating systems.  FASST is based somewhat on the SCSI standard.  Released in 1988 by Western Digital and Columbia Data Products.  Most useful in networks for allowing computers with different operating systems to access the same data.

See also: SDLP, SCSI, EIDE


FCC

Federal Communications Commission.  The US government body that oversees and regulates all telecommunications on American soil and in American airspace.


Fear, Uncertainty and Doubt (FUD)

Defined by Gene Amdahl after he left IBM to found his own company: "FUD is the fear, uncertainty, and doubt that IBM sales people instill in the minds of potential customers who might be considering Amdahl products."  The idea, of course, was to persuade them to go with safe IBM gear rather than with competitors' equipment. The acronym is frequently referred to as "the FUD factor". [Source: The Jargon File 3.0.0]  Thought by many industry-watchers to be the common emotional currency of the computer industry.

See also: GPF


femto

One quadrillionth, or a millionth of a billionth.  A femtosecond is 1/1,000,000,000,000,000 of a second.  Femto is from the Danish femien, for fifteen (note the fifteen zeros).


FFT
Fast Fourier Transformation (FFT)

A method of data manipulation used in sound and graphics.


FFTDCA

Final-Form Text Document Content Architecture: the IBM Displaywrite/370 text format.


fifth generation computer

Fifth generation computers, which are not in common use yet, are computers that use multiple CPUs or CPUs capable of processing more than one set of instructions at one time.  Current computers, even though they offer multitasking operating systems, are only capable of processing one set of instructions at one time.  Early examples of fifth generation computers are already in use; some Pentium machines use twin Pentium chips which operate simultaneously, although most software is not set up to take advantage of this extra horsepower.  There is an additional effect that comes from having multiple processors: the ability to have them communicate and combine their knowledge.  Fifth generation computers will provide the ability to allow for full speech recognition and problem-solving in ways unheard-of with current computers.

See also: fourth generation language, Pentium, multitasking, central processing unit (CPU), first generation computer, second generation computer, third generation computer, fourth generation computer


file

A contiguous block of data with a beginning and and end that is stored on a disk as a single unit and has an assigned name.

See also: directory, document


FAT
file allocation table (FAT)

In essence, a table of contents for hard disks and floppy disks.  Each hard disk or floppy disk has at least one; most contain two identical copies for security and backup.  FATs are also used by individual programs.  Most World Wide Web browsers save large caches of recently-accessed data in a special directory, and this data is usually organized by the use of a FAT.

See also: directory, file, backup, cache


file control block (FCB)

File control blocks, rarely needed with modern software, have been traditionally used to store information about a file's name, location and status.  FCB's are obsolete, and when this information is needed it is provided by a two-byte file handle that identifies each file in use by a program.

See also: handle, share, locked file


file management

The act of manipulating files on a medium such as a hard disk for the purpose of maintenance, enhanced efficiency or configuration.  Since usable  data on a PC is all stored in the form of files, file management represents the most elementary level of system maintenance for all PCs.

See also: file, directory, tree, directory structure, branch, file allocation table (FAT)


file shuttle cable

An inexpensive cable designed for rapid transmission of data between two computers in close proximity.  Generally less than ten feet in length for maximum reliability.  Most often used to transfer the contents of one computer's hard disk to the hard disk of a new system during an upgrade.  Named for File Shuttle Express, the most popular program used for this particular application.  Purchasing this software was one of few ways to aquire ready-made parallel transfer cables for many years.

See also: Centronics, null modem, parallel port


filter

A piece of software designed to scan data, determine what parts of the data are useful for the task at hand, and reject the rest.  When used with processing text, for example, a filter can be used to remove printer codes and other stray characters from a file so that it can be easily read onscreen.  In telecommunications, filters are often used for email to reject unwanted email based on characters occurring in email (e.g. filtering a specific email address would prevent all email from a specific person from showing up in one's mailbox).  Wildcards and default file extensions used in Windows dialog boxes are forms of filtering.

See also: parse, control code, wildcard, default, extension, dialog box


FIPS

Federal Information Processing Standard

Also (less common): First Interactive Partitioning Software, an IBM-compatible program for altering partitions on a hard disk without losing data.

See also: partition


firmware

Not as obvious a term as it might appear.  Rather than being a synonym for hardware, it refers to the combination of software and hardware that make up a given computing system...provided the software is in hardware form!  For example, a modem with a programmable chip does not become firmware until that chip is actually programmed.  PROM's (programmable read-only memory chips) and EPROM's (erasable PROM's) are examples of firmware.

See also: EPROM, read-only memory (ROM), volatile memory


first generation computer

These are the classic vacuum tube computers which first came into commercial use in the early 1950s and are now completely out of use.  The UNIVAC I was a classic example of one of these room-filling behemoths.

See also: second generation computer, third generation computer, fourth generation computer, fifth generation computer, VLSI, chip, integrated circuit


first in-first out (FIFO) or last in-first out (LIFO)

A method of storing and retrieving data used in programming, networking and telecommunications.  In programming, FIFO and LIFO are often used in database development to determine what order should be used to retrieve data: last item entered as the first item available, or oldest item entered as the first.  Most CPU stacks also operate on the LIFO method, while modem data buffers operate on a LIFO basis.  Modem buffers use FIFO to help manage data flow in multitasking environments so that there are fewer delays and errors in high-speed data transmissions.  FIFO is recommended for most modems 14.4kbaud and faster.

See also: stack, database, central processing unit (CPU), buffer


fixed disk

Although hard disks can now be removed and transported between computers, generally speaking fixed disk refers to the hard disk.  Almost archaic; fixed disk is a term seldom used today.

See also: hard disk


fixed point

The "point" here refers to the decimal point in a number.  Fixed point, strictly speaking, refers to a number that has a fixed decimal point regardless of how it is applied.  This is the type of math most commonly (and best) performed by modern pre-Pentium CPUs.

See also: floating point, central processing unit (CPU)


flag

A variable or quantity that can take on one of two values; a bit, particularly one that is used to indicate one of two outcomes or is used to control which of two things is to be done.  [Source: The Jargon File 3.0.0]

See also: bit, attribute, boolean operator


Flash BIOS

A form of rewritable BIOS chip which permits user upgrades via software, "in a flash", rather than requiring direct user input; a BIOS that can be upgraded without replacing the chipset.

See also: BIOS, chipset


Flash ROM

Flash ROM refers to any type of reprogrammable ROM chip or ROM chip data.  Flash ROM does not require replacement of the chip itself in order for its contents to be upgraded or altered.

See also: read-only memory (ROM), chip, Flash BIOS


flat file database

Database term referring to a a data file that is not physically related to another file or dependent on another file for its integrity.  "Flat file" also refers to a type of database that stores non-interconnected database.  A collection of business cards or names and addresses, for example, is a flat file database since changes made to information in any of the files will not affect the others.

See also: relational database, database, personal information manager


flicker

Caused by a low refresh rate or interlaced screen display, this describes the flashing effect created by inexpensive monitors set to higher color resolutions than the monitor or video card is designed to handle.  A stressor to be avoided.

See also: refresh rate, resolution, interlacing


floating point arithmetic

Floating point arithmetic is "math coprocessor territory".  It's a method of calculation that works with decimal points that change and are represented by exponents (for example 1/1000th is .001 in fixed point arithmetic and 10-3 in floating point math.  Floating point math allows for much faster calculations, a critical point in graphical applications and intensive spreadsheet recalculations.

See also: math coprocessor, fixed point arithmetic, MFLOPS


floppy disk

This term originated in the early days of disk-based data storage when two emerging technologies appeared: hard disks, designed for fixed, fast storage and retrieval; and floppy disks, designed for portability.  Floppy disks are so named because early floppies were eight-inch monsters which stored an eighth of the data today's floppies will store, and they were housed in a "floppy" thin plastic sheathing.

There are several standard sizes for floppies, but the standard today for IBM-compatibles is the 3.5" 1.44Mb floppy, which is often erroneously referred to as a "hard disk" by novices because it comes in a rigid plastic sheath.  Anyone who has slid open the aluminum door to the disk surface and gingerly pressed on the magnetic media knows that this is indeed a floppy disk.

Floppy disks are to a computer what cassettes are to a stereo system: portable data.

See also: format, hard disk, mag tape, write-protect


floptical drive

A technology released several years ago for creating high-density floppy disks which never really caught fire in the marketplace.  Due to a special barium ferrite material used in the disk and optical positioning of the heads, floptical drives allowed for up to 21Mb of data to be stored on what appeared to be a standard-type 3.5" floppy disk.

See also: removable cartridge drive, magneto-optical storage, floppy disk


FMS

Flexible Manufacturing System: group(s) of flexible cells integrated into a system.  A method of modular engineering of manufacturing processes.

See also: integrate


fnord

Hacker term, from Robert Anton Wilson's "Illuminatus Trilogy", usually misused.  Most often used as a response or tag to any surreal comment; its proper usage is as bracket indicating a secret message invisible to most people.  An example: "The New York Mets made a really stupid deal signing Wayne Gretzky fnord although it could be good for their image fnord because he doesn't play baseball." The intent is to indicate that "although it could be good for their image" is invisible to all but a few cognoscenti.

See also: hacker, Easter egg,


focus

A term used to describe the state of a window.  If a specific window is active and ready to receive input, it is said to have focus (it might make more sense to say it's in focus, but it's usually referred to as having focus).

See also: active


font

More commonly known to most people as a synonym for typeface, which is not strictly true.  Fonts differ from typefaces in that they are only single sets of characters.  A font is a graphical representation of a character set such as the numbers 0-9 or the alphabet.  There are now literally tens of thousands of graphical variations on the standard typewriter-style and newspaper-style fonts which were virtually ubiquitous for decades, and these can be applied to virtually any document on almost all graphically-based operating systems.

See also: TrueType, Adobe Type Manager, graphical user interface (GUI), typeface, jaggies


footer

Refers to information that appears on the bottom of a printed page, such as the page number and occasionally the document title or chapter title.  Can also refer to information tacked onto the end of a datafile which is used for identification of that file.

See also: header, data file


footprint

The floor or desk space taken up by a piece of hardware.  In general the smaller the better.


format

Two common meanings.  Most often used by novices to refer to the process of preparing a disk for use or describing the layout of a disk prepared for use.  To format is to lay out the arrangement of sectors and tracks on a floppy disk, hard disk or tape storage cartridge.  This formatting works like a magnetic guide, or collection of circular furrows, to tell the disk drive and computer where specific sections of data can be written.  Data is then written into the areas set aside in the formatting process when files are copied to the floppy disk.  Technically, an empty, formatted disk is actually full of data, but the data is of no value since all the bytes are identical.

Format is also used to refer to the type of structure used by a file, program, system or organizational structure, or the act of structuring data or systems to a specific standard.  For example, word processing documents can be saved or opened in a wide range of formats depending on the purpose of the document or its original source.  DOS uses a tree structure format for laying out files and directories; the hard disk's directory structure is formatted for DOS.  This lexicon comes in Windows Help format as well as plain text format; the text was formatted for use with Windows Help.

See also: floppy disk, hard disk, byte, document, tree, directory structure, word processing


FORTRAN

An abbreviation for Formula Translation: name of a universal computer language for mathematical applications; ancient in computer terms but still in wide use.

See also: COBOL


fourth generation computer

At this writing, fourth generation computers were the standard for home computers.  Fourth generation computers are characterized by the use of large-scale integrated circuits to miniaturize the unit and increase its power, but still retain the basic characteristics of third generation computers.  Some view fourth generation computers as merely an enhancement over third generation computers, not an actual subcategory unto themselves.

See also: fourth generation language, integrated circuit (IC), LSI, central processing unit (CPU), first generation computer, second generation computer, third generation computer, fiftth generation computer


fourth generation language
first, second, third and fourth generation langages (4GL)

These "generations" of computer programming languages graduate in order from those requiring most understanding of the hardware to the least.

First generation language is pure machine code, and is written in the precise binary instructions required by the chips.  It needs no compiler, because the programmer writes the program in exact instructions understandable by the hardware.  In order to write machine language, a programmer needs thorough knowledge of the  chips' functions and the precise bit patterns required to access them.

Second generation language is assembly language programming, and while it requires a compiler, it produces a fast output which should be identical to programming in pure machine language.  Second generation language programming requires thorough understanding of the functions of the hardware and the instructions the compiler uses for accessing those functions.

Third generation languages are the most commonly used today for writing software.  They require knowledge of the procedures and instructions involved and are more like learning a new dialect than a whole new language.  BASIC and Pascal are third-generation languages.  Third generation languages require strong math skills, reading skills and the ability to translate concepts into terms that the compiler can understand.

Fourth generation languages try to interpret normal human language patterns into machine-comprehensible instructions.  These are the most difficult languages to write and require enormous amounts of processing power on the machines on which they are used, which is why programming has not come down to the level where novice users can write usable software.  Fourth generation languages do not require the sophistication of third generation languages but do demand precise spelling, syntax and grammar.

Fifth generation languages are only beginning to appear and will probably not be common until the turn of the millenium.  Fifth generation languages will theoretically be able to interpret normal speech or writing into machine-usable instructions, so that a person could write a program simply by telling the hardware what to do with a given piece of data.  Fifth generation language is also referred to as natural language.  These languages will still require some thought and precision.

Sixth generation languages are still theoretical, and it is these languages which will permit anyone to voice-program a computer, as demonstrated on programs such as Star Trek, simply by issuing commands such as: "Computer, I want you to write a new letter like the one I wrote last night at eight, and change all the stuff so that it's about my vacation and not about my weekend in the country, and send it to Mom instead of my sister."

Experimental development in this level of programming is taking place at this time and is expected to be widely available within 10 to 20 years.

See also: compiler, assembler, BASIC, Pascal, syntax, chip, first generation computer, second generation computer, third generation computer, fiftth generation computer


fractal

Fractal geometry is a science which studies objects which appear similar both at large scale and small scale.  The similarity between the solar system and the atom, both of which have small objects rotating at regular intervals around a larger object, is an example of 3-D fractal geometry.  In computing, fractals generally refer to graphics created using this idea as a basis, and usually using a particular set of equations called the Mandelbrot set which very often appear to mimic geological and topological formations.

Most people find fractals fascinating due to their ability to mimic living geometry.  Free fractal generation software is available for virtually all platforms, but due to the intense mathematics involved in calculating fractal designs, math coprocessors are a distinct advantage when working with fractals.

See also: Mandelbrot set, math coprocessor


fragmentation

Refers to the state of a floppy or hard disk's files; files are fragmented when the file is separated into two or more parts located separate from one another on the same disk.  This generally slows down the performance of the system attempting to access those files; thus the need for defragmentation utilities.

See also: defragment


FRANZ LISP

"MacLISP" Descendant: a University of California at Berkeley LISP programming language spin-off developed for UNIX operating system and VAX computers.

See also: VAX, Berkeley, LISP, UNIX


freeware

A method of software distribution whereby the software in question is provided free for public use, however the copyright for the software itself resides with the author.  Freeware permits software authors and developers to release their programs free to the public and still retain control over how the software is used.  Freeware is a common method of releasing small and limited-purpose programs and fully usable demonstration versions of larger commercial packages, but nowhere near as common as shareware.

See also: shareware, public domain, license, user supported software


freeze, deadlock

A freeze occurs when two competing processes in two different programs (or, in cases of extremely poor programming, the same program) fight for the same physical resources on a computer system at the same instant.  Since binary systems are not equipped to handle two queries at the same time, this "freezes" the entire system.  Better multitasking operating systems such as System 7, OS/2 and Windows 95 can continue to function after a freeze, although the affected program(s) may have to be closed.  In less complex systems such as DOS and Windows 3.1, a freeze essentially shuts down the entire operating system until it is rebooted.

See also: crash, multitasking, operating system, OS/2, boot


front end

The hardware or software that acts as a non-processing interface to hardware or software which actually does the processing.  A banking terminal is an example of a hardware front end.  When Windows is used to copy DOS disks, Windows acts as the front end for DOS.

See also: interface, graphical user interface (GUI), shell


FTC

Federal Trade Commission (US)


PFKEY
function key (PFKEY)

Program Function Key: key which passes signal to program calling for particular function.  In most cases the functions are assigned (or assignable) by or to individual programs.  Older-style IBM-PC/XT series personal computers had ten function keys; newer AT-class keyboards have twelve.  Function keys provide access to program parameters and functions not available or providable by standard typewriter keys.

See also: IBM-PC/XT, IBM-PC/AT


GAA
gallium arsenide (GAA)

An essential compound used in manufacturing computer chips.


GCP

Graphics Control Program


GML
General Markup Language (GML)

IBM's document characteristic description language; most people now refer to relatives of GML such as HTML (HyperText Markup Language) and SGML (Standardized General Markup Language).

See also: hypertext


GPF
General Protection Fault (GPF)

General Protection Fault: a peculiar error occurring in Microsoft Windows 3.1/3.11 in which the system detects two programs fighting for the same space in memory and decides that neither of them can have it.  Windows closes the program at that point to protect its own integrity, denying the user the ability to save their data before exiting the program.  Believed by many to be perhaps the single most arrogant software design decision in the history of personal computing, as it gives the integrity of the operating system priority over the user's own data.

See also: FUD, crash


General Purpose Interface Bus, Hewlett Packard Interface Bus (GPIB, GPIB)
General Purpose Interface Bus, Hewlett Packard Interface Bus (GPIB, HPIB)

The General Purpose Interface Bus (originally designed by Hewlett Packard and also known as the Hewlett Packard Interface Bus) is a communications standard for sending data from the computer to devices such as plotters or external instruments.

See also: peripheral device, plotter


glitch

From the German "glitschen", to slip, via the Yiddish "glitshen", to slide or skid.  A sudden interruption in electric service, sanity, continuity, or program function.  Sometimes recoverable.  [Source: The Jargon File 3.0.0]

See also: bug, dirty power


GNU
GNU (FSF, Free Software Foundation, GNU-C, GNU Public License)

The Free Software Foundation is a non-profit organization dedicated to providing a full set of useful computing tools free of all copying and alteration restrictions for free public use worldwide as a means of preventing a wide gap between the information haves and have-nots.

Among its most important contributions are GNU-C, a C language and compiler with an enormous amount of support from programmers; and the GNU Public License, a copyright license created specifically for GNU which allows software authors to distribute their products free to the public while preventing any firm or individual from "taking" their ideas and monopolizing them.  There is also a popular GNU chess game for UNIX, DOS, Windows and other platforms.  GNU itself means, quite literally, GNU's Not UNIX.  We're not sure why the "G" was used.

Among the peripheral projects either loosely affiliated with FSF or using the GNU Public License are WINE, a Windows emulator that currently runs all Microsoft Windows-compatible software not requiring a VXD (device driver); FreeDOS, a project aimed at creating a fully-functioning free DOS operating system as compatible as possible with MS-DOS;  Ghostscript, a fully Adobe-compatible Postscript language; and NetHack, a dungeons'n'dragons role-playing game popular for many years.

See also: copyleft, C, emulation, freeware, public domain, license, Postscript, device driver, role-playing game (RPG)


graphical user interface (GUI)

Pronounced "gooey".  Non-text or low-text software designed to facilitate the use of a computer by reducing the amount of study and direct input required by the user to perform a specific task.  Windows, OS/2, Xwindows and Macintosh Finder are all GUI's.

See also: shell, GEM, front end, interface, operating system


GEM
Graphical Environment Manager (GEM)

A graphic interface developed by Digital Research Incorporated (DRI) and used for a time on the IBM-compatible, most notably with Ventura Publisher, the most popular desktop publishing package of the late 1980s.  It may be best-known as the graphical operating environment used on the Atari ST/Ste/TT series of PCs which were extremely popular in Europe in the late 1980s and tragically never gained market acceptance in the US.

See also: shell, graphical user interface (GUI), interface, front end, Atari, desktop publishing


Graphics Device Interface (GDI)

The software interface that handles Windows' graphics, including fonts, window graphics, and color management.  One of three main subsystems in Windows which include the kernel, graphics device interface, and user resources.

Most users know this only as something in Windows 3.1 which crashed with frightening regularity.  The reason for this is because this particular interface is given only 64K of space in memory for managing all of its functions and keeping track of all graphical activity specifically related to the function of the operating system, and some programs either insist on allocating huge amounts of this 64K "heap" for themselves and some, for example Word for Windows 6.0, refuse to release all of the used heap space when the program is closed.

GDI is probably the most problematical of the three Windows 3.1 resource heaps, and most (but by no means all) of the problems associated with managing these heaps have been solved with Windows 95.

See also: kernel, user resources, heap


GIF
Graphics Interchange Format (GIF)

A format for coding computer graphic images using data compression copyrighted by CompuServe. Until 1996 the most common graphics format used on the Internet; CompuServe asserted its copyright late in 1994 and while end users may make use of the format without payment to CompuServe, commercial users may not.  GIF is a bitmapped graphics format capable of 256 colors and unique features such as embedded commenting and interlacing.  Soon to be replaced in popularity by formats such as PNG (Portable Network Graphics).

See also: JPEG, PNG, bitmap, interlacing


graphics mode/text mode
graphics mode

Refers to a mode of graphical operation used by DOS.  Graphics mode unleashes the power of the graphics hardware where this power exists.  In graphics mode, the screen is treated at all times by the software that uses this mode as a collection of pixels where any color can be placed rather than as a collection of areas composed of dozens of pixels where only characters can be placed.  This allows a much higher level of detail and the ability to essentially draw the screen in any fashion desired by the software.

When an IBM-compatible computer is going through its boot sequence, it is in text mode, and virtually all utilities and programs included with DOS are text mode.  Windows and OS/2's GUI do all of their work in graphics mode.

See also: text mode, pixel, typeface, font, mode, boot, disk operating system (DOS), OS/2, graphical user interface (GUI)


grep

This term can either refer to a UNIX program designed to search for something by pattern (e.g. to look for all pieces of news in a newsgroup with the words "fix" and "toad" in their bodies) or the act of performing such a search.  Searching for words, phrases or similar patterns is thus referred to by many as "grepping".

See also: UNIX


greyscale

A scale of black and white, or "grey" shades and tones used to provide more accurate definition to a video image or computer graphic.  Greyscale is used where color is not available or inappropriate, for example for converting  color graphics images for desktop publishing on standard computer printers.

Greyscale can also refer to monitor displays.  Some VGA monitors permit only shades of grey to be displayed in place of the standard VGA color palette.  These monitors tend to be less stressful than color monitors for longterm use and emit considerably less radiation.

See also: shade/tone, desktop publishing, Video Graphics Array (VGA), palette, extra-low frequency (ELF) emissions


groupware

Software, usually designed to be used on a network, which allows multiple users to work on the same data and have each other's work updated in real time.  To function with reasonable efficiency, groupware requires a central file server or collection of computers capable of parallel processing, which most current computers cannot do.  Groupware is the coming wave in network-aware software.

See also: network, parallel processing, parallel processing, fifth generation computer


hack

Two primary meanings in computerdom: to create a quick and dirty solution to a problem (i.e.  to "hack together" a program that does a specific task) or the act of studying, experimenting with, or otherwise learning about a particular piece of software or hardware (e.g. " I'll stick with my word processor; I don't have the time to hack spreadsheets.)

Capitalized, Hack refers to a dungeons'n'dragons game from the late 1970s that became popular on all platforms and as a network-playable adventure.

See also: hacker, kluge, bit-bashing, role-playing game (RPG)


hacker

A person who delights in having an intimate understanding of the internal workings of a system, computers and computer networks in particular.  The term is often misused as a derogatory description, where "cracker" would be the correct pejorative term.

See also: propellerhead, Jargon File


handle

Usually refers to file handle, a two-byte block of data used by programs such as spreadsheets, accounting packages and databases requiring exclusive rights to alter a file.

Also: a means of managing large numbers of open files on a system without requiring a vast amount of memory for identification.

See also: file control block, share


hardcard

A type of hard disk originally introduced in 1985 which plugs directly into a peripheral device slot on a motherboard.  These expensive devices used less power and were more reliable than traditional hard disks due to the use of a different type of head manipulation technology (hard disks read with magnetic heads in much the same way tape heads read audio cassettes).  Newer hardcards also have exceptionally high access speeds.

See also: motherboard, peripheral device, hard disk, seek time


hard disk

Hard disks are the primary long-term high-speed storage devices used on PCs.  They are designed to store anywhere from several dozen to several thousand times the contents of a floppy disk and provide access to data at several times the rate of reading from floppies or CDs.  Hard disks are usually hard metal platters in hermetically sealed cases.  They use sensitive read/write heads similar to the heads on a cassette deck which ride a millionth of an inch above the surface of the platter, which is why early hard disks were so sensitive to movement.  A single hard disk can contain several platters, and most PCs have only one hard disk.  All modern PCs can support a minimum of two hard disks, four with special software.

Archaic: hard drive

See also: floppy disk, format, platter, interleave, hardcard, magneto-optical storage, MFM, IDE, VLB


hardwired

Can refer to either hardware or software; describes anything that is not modifiable or customizable, or something that is preconfigured and fixed (e.g. "You can't add new icons on this computer because the menu is hardwired.")

See also: default, menu, icon


HCI

Human-computer interface.

See also: interface


head crash

The most catastrophic type of crash a hard disk can experience.  Hard disk read/write heads are hermetically sealed and designed never to come in contact with the actual surface of the disk itself.  Instead, they ride about a millionth of an inch above the surface.  (Ideally this is how floppy disk heads should function as well.)  When the disk is jarred to such an extent that the head comes into contact with the surface of the disk, this is known as a head crash.  In most cases, this results in damage to the disk in and around the area where contact was made, but it can also result in damage to the drive head itself which usually requires the drive to be replaced completely.

See also: crash, hard disk, floppy disk


header

The header is the portion of the file preceding the actual usable data withing that file.  This section of the file contains information regarding the file's type, format, use, copyright and other information not strictly needed for the use of the data.

See also: format


heap

Heap has two main meanings.  In general computing, the global heap is used to refer to the amount of memory available at any one time for running a program or programs.  Windows allocates other regions of memory which it terms heaps, and these are areas reserved for storing information about various aspects of the operating system and programs running within it.

See also: fragmentation, execution, conventional memory, kernel, user resources, GDI


heat sink

A hardware component used to cool other hardware components which are adversely affected by heat.  A heat sink literally drains away excess heat energy by absorbing it and dissipating it into the surrounding atmosphere.  Heat sinks are traditionally made of conductive materials such as aluminum or cast iron, and usually have ribs to assist in dissipating heat.  Heat sinks are most often found on computers attached to CPU chips or power conversion devices in the power supply's housing.

See also: central processing unit (CPU), semiconductor


hexadecimal, hex
hexadecimal (hex)

This is the standard numerical base for programming and computer technology.  Hexadecimal stands for 16; the current world standard for numerical notation is Base 10 (meaning that a new digit is added each time 10 is reached).  Not technically correct; the earlier "sexadecimal" was considered inappropriate by IBM and their conservative edict was later adopted by the rest of the industry.

In hexadecimal notation, digits higher than 9 are represented by letters.  Therefore, in hexadecimal, 11 is represented as B.  Hexadeximal notation usually displays data as two characters to represent the 256 (16x16) possible combinations of characters.  Many programs offer the option of viewing files or areas of memory either in hexadecimal notation or as ASCII characters, and such programs provide an excellent means of comparing the differences between hexadecimal and ASCII.

See also: binary, byte, word, ASCII


HP
Hewlett Packard (HP)

Manufacturer of a wide range of computer equipment; best known for their laser printer products; also refers to the ability of certain printers to behave in the same fashion as (emulate) HP printers.

See also: HPGL, laser printer, inkjet printer, emulation


HPGL
Hewlett Packard Graphics Language (HPGL)

Programming language developed by Hewlett Packard for use with HP DeskJet and LaserJet series and compatible printers.

See also: Hewlett Packard, inkjet printer, laser printer


HGC
HGC/HGA

Hercules Graphics Card or Hercules Graphics Adapter: For many years early in IBM-compatible development considered high-end graphics.  Allowed early PC's with monochrome monitors to display graphics other than text characters and emulate CGA graphics in monochrome (with the addition of third-party software).  Hercules still manufactures high-end graphics hardware but has little consumer presence in recent years.

See also: CGA, monochrome, emulation


high-level language (HLL)

Properly refers to any non-assembler programming language.  Usually used to indicate to a language which provides greater end-user ease of programming at the expense of less direct control over the hardware itself.  Assembler is considered a low-level language due to its intense focus on hardware functions; BASIC is spoken of a high-level language due to the ease of programming and limited number of instructions.

See also: assembler, BASIC, HLLAPI


high memory area (HMA)

The most hotly-contested area of memory in the IBM-compatible DOS-based computer, the HMA is the first 64K of extended memory, or the area between 640K and 702K.  DOS wants it to load parts of the operating system to provide increased speed, Windows wants it to load certain parts of its operating system for the same reason, and many TSR programs also want it as well.

See also: extended memory, TSR, conventional memory, upper memory area, memory manager, IBM-compatible


High Performance File System (HPFS)
High-Performance File System (HPFS)

The method of tracking files and directories used by IBM's OS/2 operating system.  It was the first common IBM-compatible file system to support long filenames with mixed upper and lower-case characters.  It also uses sophisticated data management techniques to increase file access speed and allows a few other enhancements over DOS.

See also: file allocation table (FAT), OS/2, LFN, operating system, IBM-compatible


High-risk environment

This phrase relates primarily to the relative risk of virus infection faced by a given machine.  PC Glossary cites the following criteria as elements of high-risk computing environments, and a high-risk environment as meeting one or more of these criteria:

"1. You have a network connection (LAN) without a professional administrator

"2. No AntiVirus software is running on the network

"3. You use shared network programs

"4. You use a modem to download programs from BBSs and on-line services

"5. You are connected to the Internet

"6. You use preformatted floppies or recycled floppies of unknown origin

"7. You share files on floppy disks, collect software, use pirated software, and/or trade computer games

"8. Other people frequently use your computer"

We feel this is a little alarmist.  Internet connection does not per se contribute to a high-risk computing environment, for example.  Neither does downloading programs from online services and BBS'.  We feel the only four items on this list which truly contribute to a high-risk computing environment are items 2, 6, 7 and 8. The other four items suggest ignorance on the part of the author, and this list is presented here not to belittle Disston Ridge, the authors of PC Glossary, but because this particular list is so often quoted in the press.

See also: virus, Local Area Network (LAN), modem, Internet, format, piracy


High Sierra

The High Sierra specification is the basis for the ISO 9660 format, the international format standard for CD-ROM.  Seldom used any more; ISO 9660 is the common reference term now.

See also: CD-ROM, ISO


history

A term used in performance computing, and becoming more common as part of everyday computing since the release of Windows 95.  History commonly refers to a list of commands most recently executed by the operating system, or files most recently used by a program.  History lists can be maintained by a number of different programs, including Explorer and DOSKEY.EXE to allow recently-used and frequently-used commands to be recalled from memory or a file with one or two keystrokes.  This help tool also offers history, either from the button on the helpfile menu (Windows 3.1/3.11) or from the Options menu from the top menu bar (Windows 95).

See also: execution


HLLAPI

High Level Language Application Program Interface: IBM customization programming software for the 3270PC.

See also: IBM 3270, API


host drive

Used when referring to compressed disks such as those created with Stacker or Doublespace.  The host drive is the uncompressed drive or partition that holds the compressed data file, or "compressed volume".  It is assigned its own drive letter so that it cannot be confused with the "virtual" drive contained in the compressed volume.

See also: disk compression, Stacker


hotkey

A hotkey is a single key - but more commonly a combination of keys - you can use to perform a function in a program which would otherwise require several mouse movements or a similarly complex set of actions.  Hotkeys are "expert" features built into many programs so that frequent users can work directly from the keyboard and not rely upon a mouse.  Virtually all of Windows' basic functions and most application functions can be executed using hotkeys rather than mouse clicks.

See also: accelerator key, macro, shortcut key, execution


hotspot

A "clickable" area of text or graphics.  Hotspot refers to an area of text, or part or all of an image, which, when selected by an input device such as a mouse, allows the user to move to another part of a document or program.  The highlighted "See also:" words in this help tool are hotspots.  So are the abbreviations and terms used in the main screen of the lexicon.

See also: jump, hypertext


hue, shade, tone

Hue refers to the position of a color in the visible spectrum of light, as opposed to shades and tones of color which are variations in the intensity of a given color.  Yellow and red are hues, whereas pink and crimson are shades of red.  Shade refers to the amount of black in a given color; tone refers to the amount of white light or reflected white light.


hypertext

Hypertext is a generic term that refers to the way documents are structured. Hypertext can either mean text documents which are linked to other documents or bits of information to form a body of information that would be difficult to manage or understand as a single document, or it can mean a single document which contains its own built-in cross-referencing system, so that you can jump from place to place in the document by clicking a highlighted area with your mouse or highlighting it with your cursor.

Trivia

The term originated in the 1960s with computer scientist Ted Nelson, but has its roots with Vannevar Bush, a wartime advisor to US president Franklin D. Roosevelt.  He proposed a technology called Nemex, which postulated the ideal hypertext system as one in which every word was linked to other related words, topics and information.

See also: hotspot


IBM
IBM (extended topic)

IBM is an acronym for International Business Machines, the most venerable name in computing and the driving force behind the development of personal computing in the late 1970s and early 1980s.  They also manufacture larger computer systems for business and institutional use and publish software, including their own brand of DOS, OS/2 (a competitive operating system with Windows), and more specialized applications for business and institutional markets.

It is IBM who are responsible for the IBM-compatible specification being the standard used by more than 80 percent of all computers in existence today.  When they first released the IBM PC, they chose to make the specifications for this computer available - and usable without royalty - to all interested parties, a move that surprised and pleased industry-watchers.  It was partly a way of opening the door for other manufacturers to build hardware which could be added to the PC, but many manufacturers chose to build their own hardware.  IBM stuck to their guns and did the same with the release of the XT and AT-class computers, and the industry followed suit.  Apple, on the other hand, chose to keep the specification for the Macintosh to themselves  and in a very short time the low cost of IBM "clone" computers insured that the IBM-compatible/DOS computer would be the personal computing standard for at least a decade.

IBM survived partly on the strength of its name but more on the quality of their product, which was usually higher than most competitors'.  That reputation sagged with the release of several less than ideal products (e.g. IBM PC/jr and PS/2) and the adherence to software and hardware standards the rest of the industry chose not to follow (e.g. OS/2 and MicroChannel Architecture).  Today IBM is less dependent for revenues on consumer-level products than for their industrial and institutional products, although that has changed somewhat with their 1995 acquisition of Lotus.

See also: IBM PC/XT, IBM PC/AT, IBM-compatible, clone, Apple, Macintosh, MicroChannel Architecture, Lotus


IBM 3270/PC

Older IBM color PC; supported graphics, had mouse, printer and hard disk.  This is also an emulation standard for network connections with IBM mainframes and  is in common use on the Internet.

See also: Internet, network


IBM-compatible

One of the most over-used and under-comprehended terms in computing.  Strictly speaking, IBM-compatible means compatible with the specifications laid down by IBM for a specific model of computer, usually the IBM PC-AT series specification upon which DOS and Windows PCs are based.

Unfortunately, when it comes to hardware in particular, compatibility with IBM specifications does not necessarily mean the hardware will be compatible with other hardware which also claims to be IBM-compatible.  The specification does not allow for the possibility that separate pieces of hardware compatible with the AT will not be compatible with each other.

IBM-compatible is also used to refer to software designed to run on an AT-class machine or better, but what it usually means in this context is that it will run on a machine capable of running MS-DOS (usually version 3.1 or higher), whether it meets the AT specification or not.

See also: IBM PC/AT, clone


IBM PC/AT

IBM Personal Computer/Advanced Technology: the first IBM-compatible computers capable of using more than 640K of memory for running programs. 80286 and rare 80186 computers are generally referred to as AT, although much AT architecture still survives in computers as recent as 486 and Pentium class.

See also: IBM, IBM PC/XT, IBM-compatible, clone, conventional memory, 80x86


IBM PC/XT

IBM Personal Computer Extended Technology.  The first PC's used 8088-series chips originally developed by Intel and copied by other manufacturers.  These computers ran on an 8-bit bus (as opposed to Pentium's 64-bit bus) at a top speed of 4.77MHz.  The XT class essentially doubled the speed of 8-bit IBM-compatibles and was the top of the line for PC's before the AT class was introduced.

See also: IBM PC/AT, 80x86, IBM, IBM-compatible, bus


ICCP

Institute for Certification of Computer Professionals


icon

Something that represents something else.  In Windows and other graphical operating systems, including the World Wide Web, icons are generally small graphical objects linked to programs, documents or specific functions which can be loaded, started, fetched or otherwise processed by clicking or double-clicking on the graphical image.

See also: document


image

Several common meanings.  Can refer to graphical data that appears as an image on the screen such as a picture, the screen itself (when referring to your screen or monitor image), a file containing critical information about your hard disk which is used as for emergency restoration, or an exact copy of something else.  In the last case, an image refers to a copy of a floppy or hard disk saved to a single file regardless of how many files or directories it contains (called a disk image), and these are known as disk images.

See also: mirror, backup, archive


import

To bring data created with one type of software into another type of software.  A very common method of combining the results of two programs.  For example, data created with one database program can be added to a different database using different software by importing it.  Different file types can also be imported, for example a graphical object can be imported into a word processing document for addition to the formatted text.

See also: Object Linking and Embedding (OLE), Dynamic Data Exchange  (DDE), database


ICCA
Independent Computer Consultants Association (ICCA)

A self-regulating body which has been attempting for many years to establish a series of standards and codes of behavior for computer consulting.  Intensely disliked by many industry professionals for their stringent requirements for education and performance, standards which most of those currently labelling themselves as consultants cannot hope to meet, they are nonetheless a useful body and reference point for measuring a consultant's capabilities at a time when no standards exist for those labelling themselves computer consultants.

See also: FUD


Indexed Sequential Access Method (ISAM)

A method of storing and retrieving data used in database systems which provides a faster alternative to standard operating system filing methods.  Many programs designed for office use provide ISAM compatibility features for high-speed access to database records.  It functions like a disk operating system because the database records' locations are stored in a special index that functions in much the same way as a file allocation table.  This allows queries to jump straight to the requested record rather than wade through every file until the specified data is found.

See also: Structured Query Language (SQL), ORACLE, Virtual Storage Access Method (VSAM), database management system (DBMS), xBase


Industry Standard Architecture (ISA)

This is the original specification for the bus design of the IBM PC, IBM PC-XT, and IBM PC-AT compatibles.  It originally allowed an 8-bit data path and was expanded in 1984 to allow 16-bit data transfer.  Enhanced ISA (EISA) was a short-lived higher-performance standard that allowed 32-bit data transfer, but it was replaced by the much more widely used VESA Local Bus (VLB) standard on 486s and the 64-bit PCI standard used with Pentiums.

See also: bus, expansion slot, EISA, VLB, PCI, IBM-compatible


IT
information technology (IT)

Catch-all phrase for all technologies relating to computer management and dissemination of information.


initialize, INI
Initialize, init,  INI (extended topic)

Initializing is the process of setting up a system for use.  It applies equally to the clearing of memory when a computer is first turned on and to the creation of a work environment for a specific program or document within an operating system.  When the system has been configured and is ready for use, it is said to be initialized, or set to its "initial (first or original) state".

In programming, initialization is often used to signify the clearing of memory areas needed for a specific routine or program, and init is used as a mnemonic, or abbreviation, for this process (and in fact is a command available in many programming languages).

INI usually refers to a file with the extension .INI, which is used to store values used by the program when it is run, installed or accessed by the user.  Naturally, these values are the initial default values, either preselected by the program or custom-selected by the user, which the program uses to set itself up and display or perform its functions.

INI files in Windows are generally text files, and with an understanding of the terms used can be read and customized directly by the user.  INI files can store information ranging from the product serial number and user's name to window size and icon type to a complete layout of all commands and menus used by the program.  Most INI file functions from Windows 3.1 have been replaced by the Windows registry in Windows 95.

See also: boot, routine, mnemonic, default, registry


inkjet (bubblejet)
inkjet (Bubblejet) printer

Inkjet refers to a type of printer that uses fine sprays of precisely-directed liquid ink to print, first marketed at a reasonable consumer price by Hewlett Packard and used first in their ThinkJet and and later the enormously popular DeskJet printers.  Bubblejet refers to Canon's inkjet technology, which is virtually identical in function.  Inkjet printers are much quieter than dot matrix and daisy wheel printers, cost much less than laser printers, and have a print quality which is correspondingly between the two.  Unfortunately, the ink cartridges are expensive and require frequent replacement, making inkjet printers the costliest per-page investment and a poor choice for high volume printing.

See also: dot matrix printer, laser printer, daisy wheel printer, resolution


input device

Simply put, any device that allows the operator of a computer to directly affect the operation of that computer or alter its output.  Mice, joysticks, keyboards, digitizing tablets, light pens and trackballs are all examples of input devices.

See also: joystick, digitizing tablet, light pen, trackball


I/O
input/output (I/O)

Refers to the process of sending and receiving data to devices not directly associated with the CPU.  Such devices include, but are not limited to, RAM memory, disks, mice and joysticks and printers.  The acronym is not always capitalized.

See also: bus, peripheral device, memory, random access memory (RAM), joystick, BIOS


IOCS
input/output control system (IOCS)

Software for executing input/output operations.

See also: BIOS, I/O


install
install, setup

These two terms are used interchangeably and refer to the process of copying software to a location where it will be used or adding hardware to a system and configuring it for use.  In fact, DOS and Windows software packages usually come with copy and configuration programs called either INSTALL.EXE  or SETUP.EXE.

However, install and setup can also be used to differentiate between the act of putting hardware or software in a specific location (installation) and configuring it for use (setup).  These terms have subtle differences when used in conversation and in manuals and documentation, and the user should always check the context of use before assuming to understand the meaning of either term.

See also: software


integrate

The process of getting things to live, work and cooperate with each other.  A critical term in all facets of computing.  Integrated circuits are components housed in the same casing designed to function as a discreet circuit.  Integration of software and hardware is the process of getting it to communicate with other software and hardware in the system.

Due to the complexity of modern hardware and software, true integration is viewed by most in the industry as either a myth or an ideal to be strived for, not a reality.

See also: integrated circuit, large-scale integration


IC
integrated circuit (IC)

The basic building blocks of all electronics are resistors, capacitors, switches and transistors.  An integrated circuit is a collection of such components, usually miniaturized, in a single package.  In the strictest sense, an integrated circuit is a circuit unto itself and does not require other components in order to function but only a source of power.  In practice, ICs are almost always used in combination with other ICs and hardware components to create a more complex circuit.

Also, IC (chat): "I see"

See also: integrate, printed circuit board, chip, DIP, SIMM/SIPP, microprocessor


ICAM
Integrated Computer Aided Manufacturing (ICAM)

US Air Force research and development manufacturing project.

See also: integrate, CAM, CAD/CAM


Integrated Drive Electronics (IDE)

A longtime IBM-compatible standard for hard disk manufacture developed by Western Digital.  Formerly meant any hard disk whose controller components were embedded in the drive itself.  IDE hard disks have a maximum capacity of 528Mb and a maximum transfer rate of 4Mb/sec, much lower than SCSI and EIDE.  The standard also limited the system to two hard disks, which was not considered a liability as hard disks were several dollars per megabyte when the standard was first developed.

See also: integrate, EIDE, IBM-compatible


Intel

American high-tech firm responsible for developing most of the most-used microprocessors in PCs for more than a decade.  Designed and developed the first 8088, 8086 and 80186 through 80486 microprocessor chips as well as the Pentium chip.

See also: Lotus/Intel/Microsoft (LIM), 80x86, microprocessor, Pentium, DVI


interactive

Refers to software that responds to user input with actions appropriate to the response.  For example, answering a questionnaire is not an interactive activity, but answering a questionnaire whose questions change depending on the answers you give would be interactive.  This help tool, because it responds to your requests for information and does not operate independently of your requests, is interactive software.

See also: interface, input device


ICG
interactive computer graphics (ICG)

A computer system capable of graphic information display and user interaction, such as touch-screen information kiosks.

See also: light pen


IPG
Interactive Presentation Graphics (IPG)

A tool for drawing on a screen using a light pen.

See also: light pen, palmtop


IVS
interactive video systems (IVS)

Use of user feedback devices, i.e. touch screens, with laser video disk.

See also: DVI, CD-Interactive


interface

The connection between the user and the used; generally refers to software and/or hardware designed to prompt a user for input and recognize input.  Also, the act of making such a connection.

Interfaces are also known as front ends, as opposed to back end which usually refers to the operating system and/or the hardware.

See also: shell, front end, graphical user interface (GUI)


interlacing

Interlacing refers to the way a monitor displays data on the screen.  An interlaced display refreshes the screen in two passes, drawing only every other line in each pass.  This results in a flickering effect.  Non-interlaced monitors draw the entire screen in each pass, resulting in less visible flicker...but only if the monitor's refresh rate is high enough.

Non-interlaced refers to a display or a display mode which writes the whole screen in one pass.

Interlacing is also used with certain graphics formats, in particular the GIF format, to allow previewing of large or memory-intensive graphics while they load.  Interlaced graphics may require as many as six passes to fully display on the screen.

See also: flicker, refresh rate, resolution, Graphics Interchange Format (GIF), mode


interleave

Interleaving is the arrangement of sectors on a disk.  Most hard disks have circular rings, like the rings on a tree, each of which is a track.  Each surface of the track (there are always at least two since disks have at least two sides, and four or more if the disk has more than one platter) is divided into sectors, like the divisions on a clock, which contain the blocks of data to be accessed.  But because hard disks cannot always keep up with the speed of the disk's rotation, sectors are occasionally laid out in a different sequence from what might be expected.  The "two-o'clock" sector might be located at four-o'clock, and other sectors on the track might be spaced two sectors apart as well, so that the hard disk does not have to do a complete revolution to find the next sector in the sequence.  This is a slow method of accessing data, because the hard disk has to keep skipping over

sectors to get to the next readable sector of data, and fortunately interleaving is not needed by most modern hard disks.

See also; sector, track, cluster, platter


INTERLISP

User-sensitive LISP programming language developed by Bolt, Beranek and Newman and Xerox PARC for artificial intelligence.

See also: Palo Alto Research Center (PARC), artificial intelligence (AI), LISP


International Organization for Standardization (ISO)

A voluntary, nontreaty organization founded in 1946 which is responsible for creating international standards in many areas, including computers and communications.  Its members are the national standards organizations of the 89 member countries, including ANSI for the US  [Source: TAN]

See also: American National Standards Institute (ANSI)


Internet

(note the capital "I") The Internet is the largest internet in the world.  Is a three level hierarchy composed of backbone networks (e.g., NSFNET, MILNET), mid-level networks, and stub networks.  The Internet is a multiprotocol internet.


interrupt

An event that temporarily interrupts normal processing in order to transfer control to another part of the system, hardware, or piece of code.  Knowledge and understanding of interrupts, their locations and functions is critical to effective and creative programming.  An extremely large list of interrupts on the IBM-compatible is maintained by Ralf Brown and is freely available on the internet.

See also: IRQ, IRQ conflict, trap, IBM-compatible


interrupt request lines (IRQ)
interrupt request line (IRQ)

Hardware lines over which devices can send signals to get the attention of the processor when the device is ready to accept or send information.  Typically, each device connected to the computer uses a separate IRQ or arranges to share an IRQ address with another device. Some common IRQs on IBM-compatibles include:

INT 9h: reserved for the keyboard

INT 13h: A common BIOS interrupt that handles disk read/write on both floppy and hard disks

INT 16h: Also used by the keyboard

INT 21h: The most frequently-used IRQ on a PC.  Used for everything from display and keyboard functions to specialized software functions requiring access to the hardware.  It must be handled very cautiously by programmers.

INT 28h: Used primarily by DOS applications such as TSRs for performing functions when the keyboard is idle.

INT 2Ah: The critical DOS error handling IRQ.  Int2AH is the interrupt used to discover and display error messages such as "File not found", "Drive not ready" and "Missing command interpreter".

INT 33h: Usually used for the mouse and activated when a mouse driver is loaded.

See also: TSR, trap, BIOS, command interpreter, IBM-compatible


IRQ conflicts
IRQ conflict

These are probably the most common source of difficulty users experience when attempting to configure a new hardware device on an IBM-compatible.  IBM-compatibles have a limited number of IRQ's available and many devices request the same IRQ by default.  In such cases, one of the two offending devices must either be removed from the system or assigned a different IRQ.

See also: IRQ, interrupt, IBM-compatible


IVDT

Integrated Voice/Data Terminal

See also: terminal, integrate


jaggies

The "stairstep effect" shown by graphical objects when sloped lines or curves are shown on a pixel-mapped display.  (Most computer monitors are pixel-mapped.) Also refers to a similar effect displayed by bitmapped graphics.  particularly after they have been resized or stretched in one direction.

See also: font, bitmap, vector graphics, antialiasing


Jargon File

"A comprehensive compendium of hacker slang illuminating many aspects of hackish tradition, folklore, and humor." A freely-distributed periodic publication much loved and quoted by computer aficionados, particularly Internet veterans and corporate programmers.  Used as a major source for the material in this lexicon and highly recommended reading material for all potential computer/Internet addicts.

See also: hacker, Internet, acknowledgements


jiffy

The duration of one tick of the system clock on the computer.  In North America, a jiffy is 1/60 second, and this is the measurement applied by Windows 95.  A jiffy is 1/50 second in most other locations.

See also: system clock


JPEG
Joint Pictures Experts Group (JPEG)

This acronym is more often used to refer to the graphics compression standard developed by JPEG than to refer to the JPEG organization itself.  JPEG is a form of lossy compression with a number of possible options which allows reduction of true-color (16 million color) graphics data to a fraction of its original size.  It represents the next stage in graphics processing for transportability, speed and archiving from GIF's compression, offering average reductions of as much as 1/24th original size.

JPEG is known as a lossy compression scheme because it reduces the level of detail in the image as a part of the compression process, and this detail is not restored when the image is uncompressed for viewing.  JPEG is the second most popular graphics format on the World Wide Web next to GIF.

See also: data compression, Graphics Interchange Format (GIF), MPEG, archive, format


joystick

A joystick is a an input device.  The actual control is a stick, rod or handle designed to control two devices called potentiometers at the same time.  The actual controls in a joystick are like twin volume controls or balance controls on a stereo system, and function in exactly the same way.  Joysticks are usually spring-loaded so that the "balance" always returns to zero when the stick is released.

See also: trackball, light pen, peripheral device


jump

Windows' glossary refers to a jump as "text, graphics, or parts of graphics that provide links to other Help topics or to more information about the current topic." With the growth of the World Wide Web, jump has come to mean instead the act of moving from one place to another in a document, and the text or graphic that links to another spot in a help topic or Web document is known as a hotspot.

See also: hotspot, hypertext


jumper (shunt)

A small metal clip with a plastic sheath, usually about three-sixteenths of an inch square, designed to connect two pins on a circuit board.  The proper term is shunt, but jumper has become the accepted term for this device.  They are also known as Berg post jumpers or shorting posts.

See also: printed circuit board


justification

A text processing term which refers to formatting data or text so that the right margin is smooth, and all lines of text end in the same position at the right margin.  Newspapers are formatted with justified columns of text; typewriters format text with the right margin unjustified, also known as "ragged right".  Justification is available in virtually all word processors now.

See also: word processing, format


kernel

Generally speaking, the "core" of an operating system, the critical file or files used to activate and manage the routine operation of an operating system.  Two hidden files, IO.SYS and MSDOS.SYS, form the kernel of the MS-DOS operating system (these files are usually called IBMBIO.SYS and IBMDOS.SYS on newer versions of Novell DOS and PC-DOS).  Windows uses a program called KERNEL.EXE for this work.

See also: GDI, heap, operating system, user resources


key disk

A copy protection scheme which requires the user to insert a disk into the floppy drive in order to activate or install a piece of software.  Generally despised by users due to the tendency of key disks to deteriorate and require costly replacement and the cumbersome nature of the copy protection.

See also: copy protection, dongle


keyword search

A search query of a database using specific words, phrases or parts of words.  Keyword searches are used to find sections of text in a document or records in a database containing the string(s) of characters requested.  The Search function built into Windows Help and implemented in PC/Internet Lexicon is an example of keyword search.

See also: database, record, document


KB
kilobyte (K/KB), megabyte(M/MB), gigabyte(G/GB), terabyte(T/TB)

A kilobyte might logically seem to be 1,000 bytes.  It isn't.  Instead, it's 1,024 bytes, and it's interesting the way this works.  These multiples are actually exponents, or powers of 2.  8 is 2 cubed (2 to the 3rd  power); 1,024 is 2 to the 10th power.  Here's where it gets interesting…not to mention confusing, since kilo- almost always means 1,000 in other contexts.

A megabyte is a million-plus, or 1,048,576 bytes, or 2 to the 20th power.

Gigabyte, the current level of measurement used for PC hard disk storage, is a billion-plus; 1,073,741,824 bytes, or - naturally - 2 to the 30th power.

Terabyte, more often used theoretically than practically, represents a trillion-plus bytes; 1,099,511,62

7,766 to be exact.  Tera here has nothing to do with three, since it represents 2 to the 40th power.

There was no deliberate action taken to make these numbers come out to powers of 10,20,30 and 40…it just worked out that way.  So when the average computer is said to have 8MB of base memory, it actually has 8,388,608 bytes of memory available, not 8,000,000.

See also: byte, megabyte


KLIPS

1K (one thousand) Logical Inferences Per Second: a means of measuring the speed of computers used for AI applications.

See also: artificial intelligence (AI), MIPS, MFLOPS, benchmark, Whetstones, Dhrystones


kludge, kluge

From the German klug for clever.  A Rube Goldberg (or Heath Robinson) device, whether in hardware or software (a Rube Goldberg device is an extremely complex machine designed to do an extremely simple task.) also refers to a programming trick used to solve or work around a problem with a programming language, operating system or hardware device so that the resulting creation can perform either a function it should not be able to do or that it should have been able to do all along.  Although kluge is considered the proper spelling, kludge is far more common in usage.

See also: hack, hacker, routine, operating system


KE
knowledge engineering (KE)

A form of artificial intelligence.

See also: neural network, artificial intelligence, parallel processing


label
label, LABEL.EXE

The name used by a logical disk.  In DOS and Windows these labels are restricted to 11 characters and do not use the dot or period used by pre-Windows-95 files and directories.  In most cases, labels have little practical value other than as a means of identification.  On networks, however, labels are used to identify the owner of a particular drive to which a user is connected.  (For example, a user might be able to connect with more than a dozen different drives, and identifying them by the name of the user whose computer houses that drive is easier than remembering the letter.)  Volume labels are also used by backup software for keeping track of where specific files are located in a set of floppy disks and by installation software for keeping track of which disk is being installed in a multi-disk set.

LABEL.EXE is the DOS program designed to create and change volume labels.

See also: volume, eight-dot-three, network, backup, install


laptop, notebook, subnotebook

These terms have absolutely nothing to do with a computer's power, but instead concern size alone, and even then they are fuzzy at best.  Laptop refers to a portable computer with a rechargeable onboard power supply which can be carried relatively easily.  Laptops can be the size of a briefcase.  Notebook is generally used to refer to a computer that meets the above criteria and fits easily within a briefcase.  Subnotebook is smaller still, usually referring to a computer that takes up the same or less room as a 1-1/2" three-ring binder.

See also: palmtop


LSI
large scale integration (LSI)

The organization of numerous integrated circuits; basis of the modern microprocessor.  This technology permits the packaging of the equivalent of thousands of individual components in a single IC package, without which the average PC would require an amount of space equivalent to a refrigerator and more power than the average household outlet can supply.

See also: integrate, integrated circuit, VLSI


laser printer
Laser printers (extended topic)

Laser printers offer the highest quality of printout of all consumer-level PC printers, and are now affordable enough to make them viable as first family printers.

These printers function essentially like photocopiers scanners.  The computer tells the printer the layout of the ink on the page, and the printer responds by reproducing the image on paper.  Lasers do not use ink, but a dry powdered substance called toner which is also used by photocopiers.  This toner is dispensed from the toner cartridge onto a small rotating drum, where it has a positive electrostatic charge.  The laser uses the instructions given by the computer to fire onto the drum, discharging the dry toner onto the paper.  This deposited toner is then bonded, or fused, to the paper with a second roller which operates at very high temperatures.  Once the toner dries the image is smudge-free and extremely sharp, especially if the paper is designed specifically for photocopiers or laser printers.  There are also special, costlier papers for making ultra-sharp printouts which really show off the printer's precision.

Laser printers offer the twin benefits of having the best print quality and the lowest cost per page, with the disadvantages of having a relatively high initial cost and a need for fairly regular maintenance.  Depending on the print quality desired, type of connection used (parallel is preferred over serial), and amount of memory required by the printout, lasers are also the fastest of the common types of PC printers.

See also: dot matrix printer, inkjet printer, daisy wheel printer, toner, resolution


lasso

This term was reserved for Mac, Amiga and Atari users and graphic artists prior to Windows 95.  Lassoing refers to clicking and dragging the mouse to create a box which surrounds several items so that more than one item can be selected at once.  Lassoing also refers to selecting a freeform area in a graphics object for processing, cutting or copying.  Explorer permits lassoing when in iconic (graphical) view; File Manager does not.

See also: paste, Amiga, Atari, Macintosh


launch

Synonym for start or run.  Launching an application or document is the same as running it.

See also: execute, application, document


LHA
LHArc

LHArc: Lempel-Ziv/Huffman Archiving.  This is a type of data compression software designed for archiving data that needs to be restored to perfect original condition in future, and uses two separate compression schemes to achieve maximum reduction of file sizes.  No longer in popular private use; still extensively used in software development as a space-saving tool.

See also: PKZIP, data compression, archive


license

In computing, the terms and restrictions assigned to a user of a given piece of software.  The license to use a book, recording or piece of software -- not the words, music or software itself -- is what is purchased by the consumer.  This is an important distinction, and it is equally important to note that most software licenses are limited and may be revoked at any time by the copyright holder whether the person is in possession of a purchased copy of the software or not.

See also: software, piracy, Software Publishers Association (SPA), shareware, freeware, public domain


LED
light-emitting diode (LED)

A device which gives off visible light when current passes through it.  Once a standard readout device on electronic and computer equipment; now used only when actual light is needed or desirable.  Most LED operations designed to display characters (segmented displays) now use LCDs.

See also: liquid crystal display (LCD)


light pen

Once thought to be the next generation of input devices after the mouse, light pens never really caught on and probably won't find a large market with the coming of affordable voice recognition technology.  There are two common types of light pens.  In general computing, a light pen is a hand-held penlight-like device that uses a light source (often invisible infra-red) designed for pointing to light-sensitive areas of a surface such as a tablet or specially-covered monitor screen.  As a presentation device, a light pen is a penlight flashlight with a finely focussed high-intensity beam used mainly for demonstration purposes as a substitute for a pointer stick.

See also: tablet, joystick, trackball


line art

A type of graphic rendering used mainly in desktop publishing, line art uses a collection of objects drawn on the screen and represented by relative positions rather than the absolute positions used by bitmapped graphics.  A line art image can thus be stretched or resized without distortion, because the position of the various lines, curves and shaded areas are represented in the file as percentages of the image rather than specific pixels.  Bitmapped images suffer from the "jaggies" when stretched or resized.

See also: raster, bitmap, vector graphics, desktop publishing, CAD, jaggies


LPI
lines per inch (LPI)

Printing format parameter that determines line spacing (when variable) or the maximum number of lines of text a printer is capable of printing on a single page (usually 66).

See also: resolution


linker

A piece of software used by programmers and also many users who need to build their own software from component parts.  It combines modules or objects created in a given programming language into a combined, interconnected unit so that they function as a program.  Linkers can also combine code created in several different programming languages.  Linkers differ from compilers in that they join together segments of code that are already usable, whereas a compiler has to take raw text code and convert it into language understandable by the computer first.

See also: compiler, source code


lint

A program designed to clean stray characters, or "lint", from programmers' code.

See also: source code, debug


Linux

A free version of a clone of the UNIX System V Release 3.0 designed specifically for use on IBM-compatibles.  Created by Linus Torvalds of Norway, it was exceptionally well-received and supported with help, source code, applications and other contributions - most of them also free - to the point where it has become the operating system of choice for low- to medium-volume Internet providers.  It is available free on bulletin boards, FTP sites and inexpensive CDs (US$20 and under, more with manuals) containing the full operating system and a huge array of applications, utilities and source code are widely available.

See also: UNIX


liquid crystal display (LCD)

The successor to the LED, a device for displaying variable information in a fixed space.  LCDs function by the application of electrical current to a crystalline material suspended in a film of other transparent material.  The crystal itself turns from being transparent in comparison to the medium in which it is contained to being visible when electrical current is applied.  LCDs can be either monochrome, as is the case with most digital watches; or full-color, as is the case with newer laptop screens.

LCDs are made from different types of materials and use different sources of illumination depending on the circumstances in which they are used.  Most laptops use light sources located behind the screen.

Grids of thousands of LCDs on a single panel are used for the displays in laptop and notebook computers.  Basic LCD displays work on a simple on/off switching procedure and these are known as passive matrix displays, as opposed to active matrix which uses powered transistors to control the segments and refresh the screen more frequently, allowing for crisper animation and better mouse visibility.

See also: light-emitting diode (LED), laptop, gas plasma display, laptop/notebook, thin film transistor (TFT) active matrix


LISP

List Processor: first symbolic programming language developed by John McCarthy at MIT in 1958; used extensively in artificial intelligence programming.  Probably the most legendary of all the high-tech programming languages.

See also: PROLOG, high level language, artificial intelligence (AI), robotics, MacLISP, FRANZ LISP, INTERLISP


Local Area Network (LAN)

A data network intended to serve an area of only a few square kilometers or less.  Because the network is known to cover only a small area, optimizations can be made in the network signal protocols that permit data rates up to 100Mb/s.  [Source: NNSC]  Usually used to refer to small and medium-sized office-type networks or to large networks contained within a single physical location.


locked file

A locked file is a file that is in use by one program, or reserved by one program for its use only, that cannot be opened into any other program.  Locking files is a way to prevent unintentional loss of data or confusion between two sets of the same files, and is essential in networks where, for example, two accountants might try to work on the same set of accounts at the same time.  File locking prevents them from simultaneously making changes and having only one person's changes recorded.

See also: share, file control block, file handle


logical and physical drive

These two terms refer to the way hard disks are viewed by the computer.  Physical drives are actual hard disk units, and a single hard disk is a single drive.  However, a physical drive can contain many logical drives.  Logical drives appear to your computer's operating system as if they were actual, physical disks.

See also: partition, hard disk


LIPS
logical inferences per second (LIPS)

A means of measuring the speed of computers used for AI applications (not commonly used for PC's).

See also: artificial intelligence (AI), KLIPS, MIPS, MFLOPS, benchmark


long filename (LFN)

Beginning with OS/2, but common to the masses only with Windows 95, IBM-compatible operating systems began allowing filenames longer than the standard eleven-character "eight-dot-three" convention in use since the 1970s.

See also eight-dot-three, extension, OS/2


lost chains
lost chain

Lost chains are segments of data residing on a disk which once belonged to a file (and, to the computer's file system, still do) which no longer can be used or associated with the original file.  These chains are converted to data files on request when a diagnostic program called CHKDSK.EXE or Scandisk is run.  Lost chains are also occasionally complete files which have somehow been "lost" to the system and should be saved until the user is sure the system is functioning perfectly.

See also: CHKDSK.EXE, data file, file allocation table (FAT), lost cluster


lost cluster

A lost cluster is a cluster of data which is probably associated with a file currently available on the system, but because of errors in the file allocation table (FAT) directory tables there is no way to associate it with the right file.  Lost clusters are recovered the same way as lost chains, but are not usually usable without some sort of hacking.

See also: cluster, lost chain, hack, file allocation table (FAT)


Lotus

American software giant best known for making "spreadsheet" part of the popular lexicon through the enormous sales of its 1-2-3 spreadsheet; now part of IBM.  Also known for other products including Ami Pro and Notes.

See also: spreadsheet, Lotus/Intel/Microsoft (LIM)


LIM
Lotus/Intel/Microsoft (LIM)

The consortium involved in the development of the Expanded Memory Specification where this acronym is usually used (LIM-EMS).  This specification, now at revision 4.0 and unlikely to go much further, as it is not needed with newer graphic operating systems such as Windows 95, NeXTStep and OS/2.

See also: expanded memory, Lotus, Intel, Microsoft, NeXT, OS/2


Apple Macintosh
Macintosh

Apple's long-lived GUI-based personal computer built around Motorola's 68000-series CPU chip and the only serious contender to IBM-compatible market supremacy for nearly a decade.  Introduced in the mid-1980s as an alternative to the IBM PC-compatible, the Mac featured high-resolution graphics, integrated component structure, a 3.5" floppy disk drive as standard equipment, a mouse-driven interface, and a wide range of other enhancements and alternatives to the PC and last-of-the-line CP/M computers of the day.

Although many people believe the Mac is inferior both in value and performance to the Commodore Amiga and Atari ST as a PC implementation of the Motorola 68000-series CPU, Apple's marketing has managed to keep the Mac at the forefront of GUI-based computers, and its ease of use and simple maintenance have insured it an ongoing place in the PC market.  These last two features have made it especially popular with educational institutions.

See also: integrate, Apple, Amiga, Atari, graphical user interface (GUI), chip, 68000


MACLISP

Project "Mac" LISP Language Derivative: MIT LISP language for DEC; good speed, economy of storage, flexibility; used in artificial intelligence programming.

See also: LISP, artificial intelligence (AI), INTERLISP, FRANZ LISP, PROLOG


macro

Generally refers to a script, data file or available command which executes a series of instructions which would normally have to be executed in a more cumbersome fashion.

See also: data file, accelerator key, script, execution


mag tape

A form of storage still in use for large-capacity computing systems, but no longer used as a central source of data storage.  Mag tape can refer to any magnetic tape, from old-style 8-track and newer cassette tapes to tapes designed for tape backup units and DAT.  However, mag tape usually refers to the large, eight to eleven-inch open reels of tape used on mainframes and minicomputers as data storage devices.

Because tapes cannot be randomly accessed, they are not commonly used due to the low speed of data access.  Hard disks access data at much higher rates of speed because the head can jump to any point on the disk in milliseconds.  It might take several minutes for a tape device to jump from the start of the tape to data located near the endpoint.

See also: backup, DAT, tape backup, mainframe, minicomputer


magneto-optical storage

Based on the SCSI standard and in use since 1988, magneto-optical storage is used for high-capacity removable storage.  The disks themselves are 3.5" in diameter, have a capacity of 128Mb, and access speeds similar to older-style hard disks.  The recent reduction in prices of magneto-optical disks has brought this low-cost high-volume, high-speed storage within the reach of most consumers.

See also: floptical, SCSI, rewritable optical storage


mainframe

Term originally referring to the cabinet containing the central processor unit or "main frame" of a large computer.  After the emergence of smaller `minicomputer' designs in the early 1970s, the traditional big iron machines were described as "mainframe computers" and eventually just as mainframes.  The term carries the connotation of a machine designed for batch rather than interactive use, though possibly with an interactive timesharing operating system retrofitted onto it; it is especially used of machines built by IBM, Unisys, and the other great dinosaurs surviving from computing's Stone Age.  [Source: The Jargon File 3.0.0]

See also: minicomputer


Mandelbrot set

A particular branch of nonlinear fractal geometry created by the Polish-American mathematician of the same name.  He developed two sets of equations which create effects which appear to mimic topological and atmospheric phenomena such as clouds and shorelines, and provide a basis for measuring the total length of shorelines with a large degree of accuracy and predicting the shape and movement of turbulence.  The Mandelbrot sets are the most popular for computer-generated fractal images.

See also: fractal


MAP
Manufacturing Automation Protocol (MAP)

OSI standard for factory computer networking; IEEE 802.4 standard.  Also: Marketing Assistance Program; used by many computer manufacturers.


MIT
Massachusetts Institute of Technology (MIT)

Eastern US institution famous for its high-tech achievements; probably best known to Internet users as home to the RTFM archives, perhaps the largest repository of information on Internet and Internet-related topics on the the net.  Also known for developing the X-Windows graphical environment which essentially brings Mac/Windows ease of use to UNIX machines.

Also legendary in hacker circles is the MIT Artificial Intelligence Lab culture of roughly 1971 to 1983 and its feeder groups, including the Tech Model Railroad Club (TMRC), which shaped a considerable amount of hacker and general computing lore as well as a good part of the lingo.  [Source: The Jargon File 3.0.0]

See also: X-Windows, UNIX, graphical user interface (GUI), hacker


master boot record
master boot record (MBR)

Refers to the first logical sector on a floppy disk or hard disk partition, or the sector that contains critical information about the operating system and version as well as the size and capacity of the partition or disk itself.  Most hard disks have only one MBR, but it is possible to have several.  It is the first part of the disk to load into memory, even before the operating system.

See also: boot, partition, sector, boot sector


math coprocessor
math coprocessor or floating point unit (FPU)

A companion chip to the CPU designed exclusively to perform complex mathematical functions for which the CPU's fixed-point math processing is too slow.  Dramatically accelerates the performance of spreadsheet calculations, full motion video and many games and graphics applications.  Prior to the 486 series, these had to be purchased separately and tended to cost almost as much as, if not more than, the CPU chip itself.

Not all 486 chips contain math coprocessing, and in fact it has been rumored that Intel's non-coprocessor SX model 486's are physically identical to their 486-DX chips but have had the math coprocessor circuits deliberately removed, even though the circuits exist on the chip.  Coprocessor chips are usually numbered identically to their companion CPU's, must operate at the same speed, and have model numbers ending with a 7 instead of a 6 (e.g. the 80386-DX25's proper math coprocessor is an 80387-25.

See also: floating point arithmetic, MFLOPS, central processing unit (CPU), spreadsheet, 80x86, SX/DX


mean time between failures (MTBF)

How long a given device is expected to last before failure.  Varies depending on the device, its age and construction, and can be used for estimating the useful life of a single component of the whole system.

See also: bug, glitch, system fault tolerance (SFT)


Media Control Interface (MCI)

A standard interface used by Windows and other operating systems for managing multimedia devices and data.  This interface allows text, graphics, motion picture and sound to be accessed through a common interface.

See also: CD-I, DVI


MB
megabyte (Mb)

1,024,000 bytes of computer data.  A megabyte is greater than a million bytes because memory in blocks of 1,000 bytes or higher are measured in multiples of 1,024.  This is done because 1,024 is an exponent of two, which makes more computer sense and is easier to work with than 1,000 which is an exponent of 10.

See also: bit, byte


MHZ
megahertz (MHz)

One million cycles (Hertz) per second.

See also: cycle, system clock


memory

A widely misunderstood and misused term with novices.  Memory, strictly speaking, is any type of computer data storage, permanent or temporary, including RAM, disks and tapes.  Practically speaking, however, disks and tapes are almost never referred to in terms of memory, but instead are referred to in terms of their storage capacity.  This distinction prevents a lot of confusion, since memory is usually used to refer to the hardware's physical capacity for running programs and processing data at normal computing speeds.  Chip memory is thousands of times faster than storage memory.

To make matters even more confusing, virtual memory allows hard disks and other storage media to be used as slow forms of memory.

In short, memory refers to the chips on the system that store or process data, not to disks and other media designed primarily for storage.

See also: dynamic random access memory (DRAM), random access memory (RAM), read-only memory (ROM), hard disk, memory manager, chip


memory manager

Special software designed to allow the computer to make maximum use of critical areas of memory.  All operating systems use memory management code to handle moving data in and out of memory.  DOS and Windows both include memory management software.  But the term usually refers to third party software designed for managing and making available areas of memory which the operating system doesn't usually support.

Memmaker is the best-known memory manager; it's the software supplied with MS-DOS 6.0 and higher which allows access to areas outside conventional memory for loading programs and increasing the available amount of DOS memory.  Other common memory managers include QEMM and 386Max.

See also: memory, upper memory area (UMA), QEMM, 386MAX, conventional memory, extended memory


memory resident, pop-up programs
memory resident, pop-up programs (TSR's)

Memory resident refers to the method a particular program uses to load itself into memory and how it behaves when loaded.  A memory-resident program is designed to be run once and remain in memory until the system is restarted.  Also known as TSRs, such programs provide access to functions which add to the usefulness of a given program (print spoolers and disk caches are memory-resident programs).

Programs are referred to as being memory resident when they remain in memory until explicitly removed or until the power is shut off.  Some memory-resident programs can be turned off without rebooting, but this is not a normal characteristic.  Most memory-resident programs operate transparently, meaning that the user never needs to access their functions or commands once the program is run, but some operate as pop-up programs.

Pop-ups and TSRs

Pop-up programs allow access to functions such as a DOS command line, a scheduling program, address book or telephone dialler while working in a spreadsheet or even while playing a game.  SideKick (DOS) is an example of a popular pop-up memory-resident program.  Memory-resident programs must usually be used with caution because they have a high risk of interfering with the operations of complex software and most eat small or large amounts of DOS memory needed by other programs.  Pop-ups are usually used only with DOS programs, while non-pop-up TSRs are still used even with Windows 95.

See also: TSR, disk cache, spool, boot


menu

A list or group of choices available in a given computing situation.  Menu is an extremely flexible term applied to any such situation.  This lexicon, for example, uses at least five different menus.  The opening screen is a graphical menu, the list of choices represented by words at the top is the menu bar, which expands into drop-down menus when one of the choices is selected, the list of words themselves are a list menu, and under Windows 95 there is also an options menu available by right-clicking the mouse anywhere in the index window.

See also: cascading menu, control menu, drop-down menu,  context menu, menu bar, graphical user interface (GUI)


menu bar

The menu bar refers to the area at the top of nearly all program windows on graphical operating systems which contains words relating to top level of menu choices available for that program.  Selecting items from the menu bar usually produces a menu of other choices.

See also: graphical user interface (GUI)


metafile

Refers to a file type that can be moved from one platform to another, and even between standards on a single platform, without altering the nature or usability of the file.  Metafile usually refers to graphic image files which appear the same size on a screen regardless of the screen resolution and do not lose quality when displayed in this fashion.  Ordinary bitmapped graphics will appear distorted if resized to fit different screen resolutions.

See also: bitmap, jaggies, resolution, image


metal oxide semiconductor (MOS)

A special type of semiconductor used for special situations where typical silicon-based semiconductors are not appropriate or suitable  They offer the advantages of high efficiency and low sensitivity to noise (RFI).  For this reason, high-powered MOS circuits are often used in audio amplifiers, which require many times the power of a CPU chip.  PMOS stands for positive-charge MOS, and is the oldest type of MOS circuit.  NMOS uses negative charges and operates at least twice as quickly as PMOS circuits.  CMOS, or complementary MOS, is faster and more efficient than either and is the type of MOS circuit most often used in PCs.

See also: CMOS, semiconductor, radio frequency interference (RFI)


MCA
MicroChannel Architecture (MCA)

IBM's proprietary hardware design for the Personal System/2 (PS/2) series of personal computers.  Alleged by IBM marketing representatives to be widely supported in the marketplace.

See also: proprietary, ISA, VLB, PCI, IBM-compatible, IBM


microprocessor

A generic term that usually refers to a large-scale integrated circuit; a hardware component consisting of multiple transistors or switches miniaturized to allow several dozen to several million components to fit within a single housing, which includes instructions for processing data.

See also: integrate, chip, LSI, transistor, central processing unit (CPU)


MS
Microsoft (MS)

Microsoft, a software publishing firm headquartered in the US and led by Bill Gates III.  Developers of MS-DOS and Windows as well as many consumer and business-level software products in wide if not nearly universal use.  Responsible for more than 80 percent of the IBM-compatible operating system market.

Also (ms): abbreviation for manuscript.

See also: disk operating system (DOS), Windows NT, IBM-compatible


MFLOPS
million floating-point operations per second (MFLOPS)

A measurement of the mathematical speed of a processor as opposed to its raw calculation speed.  Useful in determining a chip's usefulness for video rendering and math-intensive applications such as spreadsheets.

See also: floating point unit (FPU), floating point arithmetic, spreadsheet


MIDI adapter

A peripheral card or hardware adapter included on another card such as a sound card used for connecting a MIDI-capable instrument to a PC.  MIDI devices can be daisy-chained to allow a virtual orchestra of sound, effects and recording devices to all be connected to the same computer.

See also: daisy chain, MIDI, synthesizer


minicomputer

Usually refers to a computer with computing power between that of a standard PC and a mainframe or supercomputer.  Usually used as central data processing units on networks.  The definition changes as the design of computers changes.  The average PC today is many times more powerful than the minicomputers of just ten years ago.

See also: mainframe


minimize, maximize

Minimizing refers to reducing a window to its smallest possible size to clear the desktop.  In Windows 3.1/3.11, minimizing a program or a window within a program reduces the window to an icon.  In Windows 95, minimizing a program zooms it down to a spot on the Start menu bar.  Minimizing a window within a program zooms the window down to a small bar at the bottom of the program's window.  When a program or window is minimized, all the data is still there and the program is still open; it just takes up less space on the screen and sits idle while the user works elsewhere.

Maximizing refers to enlarging a program window to fill the entire screen.  A window within a program can also be maximized so that it fills the full window in that particular program.

Minimizing or maximizing a window has no effect on how quickly or slowly a program functions unless a program is specifically set up to respond to minimize/maximize in this way.

See also: icon, menu bar,


MIPS
millions of instructions per second (MIPS)

A measurement of raw machine performance for computing devices.

See also: MFLOPS, benchmark, KLIPS


mirror

Refers to the act of copying the contents of a disk or section of a disk to another disk for purposes of archive storage or backup.  It was not commonly used on PCs due to the high cost of hard disks, but with newer hard disks priced at half or less the cost per megabyte of floppy disks, many users now use a second or third hard disk as their backup unit.

On the Internet, mirror can refer to either the act of mirroring a disk or

See also: archive, backup


mnemonics
mnemonic

An abbreviation for a common computer instruction, usually used in programming or as hacker slang in email and documentation.  INIT is a mnemonic for Initialize, for example, and STDIO is a mnemonic for Standard Input/Output.  Used most commonly as instructions in assembly language programming.  In general conversation, mnemonics refers to anything intended to assist the memory.

See also: assembly language


moby

From Herman Melville's "Moby Dick": hacker slang for large or huge.

See also: hacker, The Jargon File


mode
mode, MODE.COM

State or attitude.  Concerning computers, the state or configuration of a piece of hardware or software (e.g. "Windows usually boots in enhanced mode to provide access to its multitasking features, but you can also use standard mode, which will get a single task done faster.") As hacker slang, the current state of mind or attitude of the individual (e.g. "I've been up all night taking care of a problem I didn't cause, so be warned: I'm in vengeance mode right now.")

MODE.COM is a DOS program designed to set many device parameters, including keyboard layout and international alphabets, printer and serial port settings.

See also: boot, enhanced mode, multitasking, hacker, keyboard layout, serial port


MODEM
modem, FAX/modem

An acronym for MOdulator-DEModulator, a hardware device that permits computers to communicate and transfer files with other computers over a telephone line.  Properly capitalized; now commonly used in lower-case letters.

FAX/modems are modems which have the capability of either sending or sending and receiving FAX transmissions.  Virtually all new modems manufactured for consumer use are FAX capable.

See also: FAX


MFM
Modified Frequency Modulation (MFM)

The standard specification used for formatting and accessing hard disks prior to the IDE specification.  This format allowed for hard disks larger than 32Mb and offered significant improvements in performance over the ST506 standard in line with the needs of AT-class systems in use at the time this standard was popular.  Obsolete.

See also: RLL, IDE, hard disk, format, ST506,AT


Modula
Modula/Modula 2

Once considered a rising star, an object-oriented programming language from Europe similar to Pascal.

See also: object-oriented, Pascal


monochrome

Having only one color.  Indicates that a program or computer monitor can only display one color: with monitors, usually white, orange, amber or green.

See also: greyscale


MDA
Monochrome Display Adapter (MDA)

A single color PC display adapter; also used synonymously with TTL in describing monitor and adapter types for older PC's.  Still widely used but not supported in the marketplace.

Perhaps just as common: MDA: abbreviation for methylene desoxyamphetamine, a recreational drug popular with the hacker/rave subculture.

See also: CGA, Hercules, hacker


motherboard

The main circuit board on a computer which houses the CPU and to which all other peripheral devices used by the computer must be connected.

See also: daughterboard, printed circuit board, central processing unit (CPU),peripheral device


Motion Pictures Experts Group (MPEG)

Known mainly to computer users as the body responsible for developing the MPEG compression standard used for full motion video on computers.  This compression scheme usually requires hardware in order to display video at a reasonable resolution and in full-screen mode as opposed to a small window, but it is usable on most 486-plus computers for small animations and videos.

MPEG has also developed data compression schemes for audio as well, which allow near-CD-quality audio in as little as 1/20 the space normally required.  This allows artists to offer full-length songs in stereo for download on bulletin boards and the Internet in files just a few megabytes in size, instead of the dozens of megabytes required for full CD audio quality.  MPEG-encoded audio files usually have the MP2 extension.

MPEG is expected to be the standard for computer video for the next several years.

See also: data compression, JPEG, resolution, 486, CD, Internet


Motorola

American high-tech giant since the 1930s.  Motorola came to prominence as a car radio manufacturer.  They were known in the 1950s and 1960s as television manufacturers and now are known for being the manufacturers of the microprocessing chips used in Atari ST, Macintosh, Amiga, NeXT and PowerPC computers.

Based on the original 16-bit 68000-series design, Motorola 680x0 chips are widely acknowledged as being superior in design and performance to comparable Intel-developed chips, another case of Betamax syndrome, in which the inferior product grabbed the lion's share of the market.  Motorola now focuses its efforts on development and manufacture of next-generation RISC chips which are currently the workstation standard and will be the PC standard for the late 1990s.

See also: Atari, Macintosh, Amiga, NeXT, PowerPC, RISC, Betamax syndrome


mount

Mounting is the process of installing a disk drive, compressed disk volume, or other storage device, to an operating system which is already up and running.  Most PC users never need to mount a disk since the system does it automatically at boot.  Used most frequently with compressed disks created with programs such as Doublespace/Drivespace or Stacker, or on large computer systems where individual storage units can be added or subtracted to the system "on the fly".

See also: disk compression, boot, Stacker


mouse elbow, mouse shoulder

Similar to tennis elbow; a painful or irritating disorder stemming from poor mouse posture.  A mouse should properly be handled with the heel and side of the hand resting on the desktop rather than suspended over the mouse itself.  Mouse shoulder is a painful or irritating cramp or tension in the shoulder which stems from poor wrist and elbow support.  Ideally, more than half of the forearm should be supported by an armrest or the desktop.

See also: ergonomics, repetitive strain injury (RSI), carpal tunnel syndrome, trackball


MPR II

Acronym for the Swedish standard for radio frequency emissions (especially ELF) for computer monitors.  TVM was the first popular manufacturer to establish a consumer-level reputation as a supplier of MPR-II compliant monitors, and now almost every manufacturer has MPR-II compliant models available.  Monitors conforming to this specification are highly recommended, especially in light of World Health Organization recommendations in regard to ELF radiation.

See also: extremely low frequency radiation (ELF), radio frequency interference (RFI), ergonomics


MSS

Massive Storage System

Also: mss: manuscripts (plural, lower case)


Multi-Synch

Strictly speaking, refers to models of computer monitors manufactured by NEC capable of operating on several different frequencies and on several different platforms.  Most monitors advertised as multi-synch offer variable frequency only, not variable platform capability.

See also: refresh rate


multitasking

Refers to the capacity of a program or operating system to perform two tasks at the same instant in time.  There are two common types of multitasking, one known as pre-emptive and the other as cooperative.

Windows 3.1 and Macintosh Multifinder, the most popular "multitasking" systems, uses time slice multitasking which essentially allows only one program or process within a program to access the CPU at one time.  This is known as pre-emptive multitasking, since at any given moment all other applications are pre-empted by the demands of the task using the processor at that moment.

Windows 95 and OS/2 are cooperative multitasking systems, also known as multithreading, and actually divide up processor time between all the tasks and applications running at a given moment.  Cooperative multitasking generally appears smoother to the operator and if properly constructed is also a little faster than cooperative multitasking.

See also: task, multithreading, central processing unit (CPU), time slice, operating system


multithreading

The name most often used now to refer to true multitasking of the type used by Windows 95 and OS/2.  Multithreading makes use of a procedure that allows the entire operating system to be a single process, and assigns parts of that process to each program running on the system.  Memory is shared dynamically, meaning that it is allocated to programs as needed, not in fixed amounts.  In this fashion, the operating system as a whole can access the CPU and use its own schemes for dividing up the use of processor time.  It is a much smoother and - when properly constructed - more efficient method of multitasking than the time slice multitasking used by Windows 3.1 and DesqView (a DOS multitasking system).

See also: task, OS/2, multitasking, time slice, central processing unit (CPU)


MIDI
Musical Instrument Digital Interface (MIDI)

The MIDI specification is developed and approved by the MIDI Manufacturers Association (MMA).  An archaic standard in computing terms (in its current state its core specification dates back to the early 1980s), it provides a means of allowing song data and instrument settings to be translated between programs and across platforms.  It is the specification used for configuring synthesizers to play music on most PCs equipped with sound cards, and is also in wide use in the music industry in electronic devices of all description.

See also: synthesizer, MIDI adapter


naming convention

Refers to the rules governing the naming of files on a given operating system, although some programs that provide file management capabilities may also have their own unique naming conventions.

Examples of naming conventions include DOS' eight-dot-three, which allows a maximum of eight characters followed by a dot followed by a maximum of three characters as an extension; UNIX naming convention, in which capital letters and long filenames may be used, but which may not include spaces or certain types of punctuation; and Windows 95 naming convention which allows long filenames and spaces, but not certain types of punctuation.

See also: file, extension, eight-dot-three, UNIX, long filename (LFN), syntax


nano
nano-

Prefix for billionth.  A nanosecond is a billionth of a a second.  Modern RAM chips measure their speed in nanoseconds, and most PCs use RAM which can be accessed in 50 to 70 nanoseconds.

See also: pico-, random access memory (RAM), chip


National Computer Graphics Alliance (NCGA)

A professional organization founded in 1979 to promote computer graphics at both the business and private levels and help establish standards of performance for computer graphics hardware.

See also: National Television Standards Committee (NTSC), National Software Testing Laboratories (NSTL)


National Software Testing Laboratories (NSTL)

It began in 1983 with the objective of being a comparative testing clearinghouse for computer hardware and software.  Today it is a full-fledged, impartial independent research organization specificaly focussed on testing of microcomputer technology.

See also: benchmark, National Television Standards Committee (NTSC), NCGA


National Television Standards Committee (NTSC)

Committee responsible for approving standards for data transmission using television signals.  NTSC is the format used for both professional and consumer-level videotape in North America

Also: refers to a video display type, used mainly for high-resolution 16 million color Targa graphics.

See also: PAL, SECAM


network

A computer network is a data communications system which interconnects computer systems at various different sites.   A network may be composed of any combination of LANs, MANs or WANs.

See also: Local Area Network (LAN), Internet


neural network

Quite literally, a network of nerves.  The idea behind neural networking is to create hardware or software constructions that behave and respond like living nerve cells.  Networks of "nerve cells" can then be configured to behave like living beings.  Neural networking is the core technology behind artificial intelligence and adaptive learning.

See also: artificial intelligence, robotics, PROLOG, LISP, Turing machine


NeXT, NEXTSTEP

Spearheaded by Steve Jobs, one of the cofounders of Apple Computers, it was believed by many that NeXT Computers would become the new Macintosh: the more-powerful, easier-to-use alternative to the IBM-compatible.  While it gained a following on university campuses and in institutions, which were the only places the computers were ever widely available, it never made it as a consumer product which many people felt was a shame.  NeXT stopped production in February of 1993.

The original NeXTcube systems, the most elegant-looking computers of their time, came with Motorola 68030 or 68040 processors equivalent in power to mid-level 80486 CPUs, the best bundled collection of software ever seen on a new computer platform, and monochrome monitors.  (Color was available as an add-on, and the quality was high enough to make NeXT's much-coveted graphics machines for their day.)

Regardless of the reasons for this failure, the NeXT still maintains a loyal userbase among hobbyists, and its graphical interface, NEXTSTEP, is available on most popular platforms as a software addition.  Some of NeXT's most interesting ideas have been incorporated into other operating systems; Windows 95's Start menu bar can credit NeXT for at least some of its ancestry.

See also: Apple, Macintosh, IBM-compatible, Motorola, 680x0, central processing unit (CPU), bundle, platform, operating system


nibble

Four bits; one hex digit; a half-byte.  Though byte is now techspeak, this useful relative is still jargon.  [Source: The Jargon File 3.0.0]  Seldom used except as "insider" jargon or in assembly language programming.

See also: bit, byte, word, assembler


non-maskable interrupt (NMI)

A critical interrupt used for handling catastrophic or potentially catastrophic system events.  NMI's are addressable directly through a special NMI pin on the CPU.

See also: interrupt, IRQ, central processing unit (CPU)


NRAM
Non-volatile RAM (NRAM)

A normally small area of memory in higher-end modems that stores settings and information when modem is turned off.  Also refers to any type of RAM which does not lose its contents when powered down.

See also: dynamic random access memory (DRAM), static RAM (SRAM), bubble memory, CMOS


non-Windows application

Quite simply a DOS application run in Windows.  Jargon which has no practical value except to make Windows that much more difficult to understand.

See also: FUD, program information file (PIF)


North American Presentation-Level Protocol Syntax (NAPLPS)

A data transmission format for transmitting text and graphical information together in the same file.  Still used in some videotext applications such as closed-captioning, but largely replaced in general computing by other protocols.

See also: National Television Standards Committee (NTSC)


Norton, Peter Norton

Peter Norton is legendary as the developer of Norton Utilities, the most popular PC utilities package in history, now marketed by Symantec.  Other extremely popular products bearing Norton's name are Norton Commander, a much-loved DOS command shell; Norton Desktop, a favorite Windows utility package and interface replacement; and Norton Navigator, a series of extensions for Windows 95.  Norton Utilities are considered to be the most useful and essential utilities package in existence for serious PC tinkerers.

"Norton" products are published by Symantec, which in 1994 merged with Central Point software, their closest competitor.

See also: utility


Novell, Novell Netware

American software giant responsible for the world's most popular Local Area Networking software for the DOS operating system, which is known as Netware.  Also involved in consumer-level marketing as publishers of Novell DOS and now as the owners of WordPerfect.

See also: WordPerfect, network, disk operating system (DOS)


null modem cable, nullmodem

A "modem-eliminator adapter", an inexpensive cable designed to connect two computers via their serial ports, occasionally used for file transfers but more often used for low-speed networking via serial ports.

See also: file shuttle cable, serial port


NC
numerical control (NC)

Pre-assigned instructions for machine tools; an acronym used in manufacturing and programming for the manufacturing industry.


Object Linking and Embedding (OLE)

A method used by Windows for transferring and exchanging information between applications.  OLE allows files edited in one application to be used in another, and to be changed by the application which created the object without physically removing the data from documents using the data.  An extremely powerful and flexible means of manipulating and managing data from several applications, and used extensively by "suites" such as Works, Office and Internet packages.

See also: Dynamic Data Exchange (DDE), document, multitasking


object-oriented

Based upon modules rather than single discreet units.  The term is used to describe software and software interfaces as well as programming languages.  An object-oriented interface might use graphical buttons or pictures to click which perform certain functions, as opposed to a normal interface which requires typing series of commands.

Object-oriented programming languages, which include Modula, Pascal and Visual Basic, allow programmers to create software modules which are then linked together to perform the functions of the program.

See also: object-oriented interface (OOI), linker, Modula, Pascal, Visual Basic


object-oriented interface (OOI)

Not quite synonymous with graphical user interface (GUI), OOI refers to an interface which uses graphics (such as Windows icons) or tangible items to be selected (such as a push-button menu that uses buttons shaped like the things they represent) as opposed to text.

See also: graphical user interface (GUI), object-oriented, icon


OED

Acronym for The Oxford English Dictionary, used in documents (but not this document) containing cited definitions from "the Oxford".

See also: The Jargon File


O/S
operating system (OS)

Operating systems are the programs or collections of programs which act as translators between a computer's processing chips and programs designed to run on them. They are pretty useless on their own, like an empty house with no furniture. They only become useful when other programs apply them to specific tasks.

Examples of operating systems are DOS, Windows, OS/2, UNIX and Macintosh's System/Finder.  Because of the way they are packaged, many people confuse operating systems themselves and operating system packages.  Windows' Notepad and Paintbrush are not part of the operating system, but rather are bundled programs designed to be used with it.

See also: kernel, disk operating system (DOS), OS/2, UNIX, Macintosh, bundle


OS/2
Operating System/2 (OS/2, Warp)

IBM's successor to MS-DOS and Windows, originally a joint project between Microsoft and IBM.  Microsoft later decided to develop Windows as an operating system in its own right.  Said by hardcore hackers to be a vastly superior operating system to Windows, both OS/2 2.1 and OS/2 3.0 (also known as Warp) suffered from an inability to walk novice users through elementary tasks at even Windows' poor level, and thus never became the serious challengers to Windows which industry watchers had hoped.

OS/2 is a superb platform for many memory- and processor-intensive applications; a bust as a consumer-level operating system.  Another victim of Betamax syndrome; often derogatorily referred to by ardent Windows fans as "half the operating system".

See also: Betamax syndrome, operating system, hacker, FUD, airplane rule, IBM


OCR
optical character recognition (OCR)

Machine identification of printed characters.  A technology which permits the conversion of printed text to digital text for ease of storage, conversion and transmission.  Used primarily to convert existing text and documentation for use on computers.  OCR has been an extremely difficult technology to master due to the difficulty of determining the nature of characters created with different fonts and typefaces.

See also: scanner, font, typeface


ORACLE
ORACLE, ODBC

An operating system used mainly on databasing networks capable of supporting parallel processing; extremely powerful and flexible and becoming very popular with businesses and institutions.  ORACLE essentially supports a wide range of database file and format types to allow combining and converting database information for a wide range of uses.

ODBC stands for ORACLE database compatibility, a facility built into many application suites, particularly those designed for office use.

See also: Structured Query Language (SQL), database, parallel processing


Original Equipment Manufacturer (OEM)
original/other equipment manufacturer (OEM)

Although it could be applied to any industry, it is primarily used in the computer industry to refer to any manufacturer selling product to resellers.  Peculiarly, the term also refers to the reseller as well, so while Microsoft is an OEM for Windows, your local computer vendor who offers Windows for sale is also an OEM.  In order to distinguish between the activities of the two types of business, VAR, or value-added reseller, is usually used to refer to the actual retailer.

See also: value-added reseller (VAR)


orphan/widow

Word processing and publishing terms dating back decades which relate to page layout.  An orphan is a line or half-line of text that ends a paragraph and sits alone at the top of a page, while a widow is a first line of a paragraph that sits alone at the bottom of a page.  Both are deemed to be undesirable design elements in publishing and word processing.

See also: word processing


overlay

Refers to part of a DOS program that resides in a separate file from the main program file and is loaded into memory as needed for its functions.  Overlays are used to get around DOS' 640K memory limit and allow DOS programs to perform functions or groups of functions which would otherwise require more than the maximum available amount of DOS memory.

See also: conventional memory, program


pack, unpack

These are usually used as slang terms for archive and unarchive which have fallen into common usage.  Packing refers to processing a file or set of files using data compression or backup software for the purpose of archiving, copying or transmission.  Unpacking, naturally, refers to the process of extracting the compressed data.

Not to be confused with PAK.EXE, file compression software from NoGate Consulting; or PKPAK.EXE/PKUNPAK.EXE, programs by PKWARE which are designed to process specific types of compressed archives.

See also: archive, data compression, backup, PKZIP


page

In general computing, page has two meanings.

A page usually refers to a block of data designed to be moved in and out of memory as needed.  The size of this block depends on the application creating the page.  EMS uses pages of memory 64K in size to manage applications needing more than the base 640k of memory allowed by DOS.  ROM's also use pages to accelerate the movement of ROM data to and from the computer, improving the performance of the system.  Text mode DOS also uses a page, 4096 bytes in length, for handling text graphics.

It can also refer to a screenful of text information in DOS text mode.  A single screen of data is referred to as a screen page.

See also: Expanded Memory Specification (EMS), read-only memory (ROM), text mode, paging


paging

Several meanings.  Telecommunications: both the process of alerting the user of a remote message retrieval service that a new message has been received and the action of requesting the presence of a system operator or administrator on a BBS or TELNET site at the terminal for live chat or assistance.

In memory management, paging refers to the process of moving blocks of memory in and out of a particular location.  "Paging" is how expanded memory allows DOS programs to take advantage of more than 640K of memory, since it manages those blocks in 16K to 64K chunks which can be swapped back and forth with up to 32Mb of memory in the computer even on the oldest PCs.  This 64K window through which all extra memory must be shuttled is known as the page frame.

See also: terminal, expanded memory, extended memory, page


PAL, SECAM

PAL and SECAM refer to TV broadcasting and videotape standards used in Europe and Asia.  The two are not compatible, so the two formats must be converted for retransmission when broadcast and videotape material are transferred between countries using the different formats.  PAL uses a 625-line screen at 25 frames/second and SECAM provides for 819 lines, a significant improvement over NTSC's 525-line screen image.

See also: National Television Standards Committee (NTSC), resolution, refresh rate


palette

This is to computers what artists' palettes are to their paintings: a collection of available colors.  The exact hue, shade and appearance of those colors depends on the video driver software available and the manufacture of the monitor.

See also: hue, color depth


palmtop computer

The most recent generation of ultra-small computers places the computing power of the earliest IBM-compatible and Macintosh computers literally in the palm of the user's hand.  Palmtop generally refers to any computer able to be held in the palm of one hand while input is given with the other.  Palmtops have actually been around for many years, but most have been little more than glorified address and appointment books.  The most recent models allow full computing capability and access to a fairly wide range of software, but not surprisingly the most common current use for palmtops is storing addresses and appointments.

Interfaces for palmtops vary depending on the make and model.  Examples of more recent palmtop computers are the Atari Portfolio, equivalent to a 256K DOS computer; the Casio BOSS, a less powerful unit which offers a miniaturized traditional QWERTY keyboard layout as well; and the Apple Newton, as powerful as the early Macs, which allows the user to enter data as if writing on a sheet of paper.

See also: laptop, QWERTY keyboard, personal information manager


PARC
Palo Alto Research Center (PARC)

The legendary Xerox think tank.


parallel port

A hardware channel that provides access to a parallel device, usually a printer.  Parallel port transmissions offer an 8-bit data path (bus) as compared to the 1-bit data path of a serial port.  Virtually all parallel ports on PCs conform to the Centronics 23-pin interface specification.

See also: RS-232, port, serial port, Centronics, bus


parallel processing

A feature of the latest generation of PCs.  Parallel processing is the ability of a computer to use more than one CPU simultaneously.  Some recent Pentium and Pentium Pro series computers offer two to four Pentium chips on the same motherboard, which allows the system to perform two to four tasks simultaneously without slowing the system down.  As the technology develops, this capability will expand to allow the two processors to communicate with each other about the data they are processing and literally increase the computing capacity of a PC not by two, but by a factor of two.  Parallel processing represents the key to implementing fifth-generation computing.

See also: Pentium, motherboard, fifth-generation computer, artificial intelligence


parameter
parameter, argument

Refers to a legal value used by a specific piece of software or hardware, but it is also used to refer to commands designed for inputting these values.  For example, Windows Help offers several optional commands for loading helpfiles.  The command winhelp -i port pclex.hlp will take you directly to the definition for "port", because that's how the software was created.  However, "-i" is a command, not a parameter, since it tells WINHELP.EXE to jump to a specific topic.  The parameters are "port", the topic; and "pclex.hlp", the specific helpfile containing that topic.

Argument and parameter are often used interchangeably, although strictly speaking an argument is a variable command that is fixed while a parameter is considered to have a potential range of values.  Arguments also refer to commands issued in actual programming which have one-way, fixed values.

In casual conversation, parameter and argument are both often used to refer to all additional commands added to a program launch command.  While this is not technically correct, as shown above, it is still very common.

See also: port, launch


parse

A term most people forget after completing twelfth grade English: to deduce or formularize the structure of a series of words or phrases.  In computing, parsing usually refer to the process of determining the structure of documents prior to filtering.

See also: filter, document


partition

Refers either to a physical section of a hard disk or to the act of creating such a section.  Partitioning is a method of dividing up a physical drive for the purpose of organization, versatility or security.  A single disk (usually a hard disk) can be set up to behave as if it is actually several different hard disks (logical drives).  These sections are actual sections of the disk and cannot be divided up so that half of one partition is at the start of the disk and the other half is at the end.  Partitioning is done to help organize data on larger or more complex systems, and also to allow one computer to run more than one operating system to its full capacity.  For example, OS/2 and Windows 3.1 can both reside and run from the same partition, but OS/2 will function more efficiently if it resides on its own partition.

See also: logical drive, hard disk, OS/2


Pascal

An object-oriented programming language based on Algol and designed by Niklaus Wirth on the CDC 6600 around 1967/68 as an instructional tool for elementary programming.  Limited in scope but still capable of producing quite useful applications.  There are at least several hundred Windows applications coded in Pascal currently circulating on the net and thousands if not tens of thousands of Pascal DOS programs.

See also: object-oriented, BASIC


paste

Refers to working with the clipboard.  Data copied or cut from one file is placed into another by pasting from the clipboard.

See also: clipboard, buffer, cursor


patch

Either a fix for an existing problem, a file used to replace code in an existing product for purposes of fixing bugs or updating features, or the act of fixing a bug.

See also: bug, debug, update


path

A path is the "street address" of a file or directory, and specifies the route that must be taken through the disk's directory structure to get to it.  It functions like a street address in reverse, with the "country" name (drive) first and the street number (name of the specified file or directory) last.  Paths are usually referred to one of four ways: full path, directory path, absolute path and relative path.  Refer to the extended topic on path types. for more information on path syntax for DOS and Windows.

See also: directory structure, directory, syntax


path types
Path types (extended topic)

There are four main methods of describing paths in DOS and Windows: full path, directory path, absolute path and relative path.

Full path: the complete path of a file.  Includes all directories above the file and the full name of the target file.  For example:

C:\WINDOWS\SYSTEM.USER.EXE

…is the path to a file used by Windows called USER.EXE.

Directory path: the complete path of a file or directory but without the name of the file itself.  Directory paths are usually used to point to a directory where files are to be saved or where a specific file or group of files may be found.  For example, Windows system files are usually located in the directory path:

C:\WINDOWS\SYSTEM

Under standard DOS and Windows syntax, a directory path does not always have to include the trailing slash, although the rules regarding this syntax vary from program to program.

Absolute path and relative path: used in relation to the directory in which the user is working.  Absolute path includes the full path or directory path including the drive letter.  For example:

C:\WINDOWS\SYSTEM\USER.EXE

…is the absolute path for the file USER.EXE regardless of the current working directory.  However, if the user is currently in the C:\DOS directory, the relative path would be written as an "up-and-over" path, like so:

..\WINDOWS\SYSTEM\USER.EXE

The two dots here stand for "up one level of directories".


Program Design Language or Page Description (PDL)
PDL

Program Design Language: any of a large class of formal and profoundly useless pseudo-languages in which management forces one to design programs.

Also: Page Description Language: refers to any language which is used to control a graphics device, usually a laser printer.  The most common example is, of course, Adobe's PostScript language, but there are many others, such as Xerox InterPress, etc.  [Source: The Jargon File 3.0.0]

Also: Program Development Language.

See also: Adobe, laser printer, PostScript


PC
personal computer (PC)

A computer capable of stand-alone processing or linking to host as part of a network; a computer affordable for individuals or families on average incomes.

See also: minicomputer, network


PE

Processing Element

Also: Professional Engineer: professional and legal accreditation for engineering professionals.

See also: SME


peek

The BASIC programming command for directly accessing memory contents at a specific address.

See also: poke, BASIC


Pentium
Pentium, Pentium Pro

Intel's successor to the 80486 microprocessor and described in depth on the Chip Chart, the Pentium is probably best-known for the mathematics bug in early models which caused errors in calculations.  While there is some dispute about how serious the problem really was for average users, Intel offered free upgrades for owners of the buggy CPUs anyhow and apparently the bugged chips wound up in low-end Pentium machines designed for the home computer market where the flaw would not be as noticeable.  Apparently Intel did not require that those purchasing such machines be informed of the flaw.

The name stems from its being the fifth generation of Intel CPU, and was so named because Intel was unable to trademark a number (80586, the projected model number).

The Pentium Pro, expected to be Intel's sixth generation chip, is merely an enhancement over the Pentium, and provides the smallest degree of improvement in performance of any generation of Intel chip.  It was being marketed in 1995 as a high-performance upgrade to the Pentium, not as a new generation.

See also: Intel, 80x86, microprocessor, upgrade, bug,


peripheral card, peripheral device

Peripheral card is a generic term used to denote any circuit board designed to plug directly into the main circuit board of a computer for the purpose of connecting another device to the computer.  Peripheral cards are used to provide connectors and interfaces for printers, joysticks, scanners, speakers, TV tuners and other externally-connected devices.

The devices themselves are known as peripheral devices because they are not contained as internal components of the computer, although peripheral device is often used to refer to modems, sound cards and other devices housed within the computer itself.

See also: adapter, printed circuit board, joystick, scanner, modem


PCI
Peripheral Component Interconnect (PCI)

Intel standard specification for data i/o and peripheral card specifications used primarily on Pentium/Pentium Pro equipped computers and also on some newer 486 series IBM-compatibles.  PCI is the next step in improving system performance by allowing high-performance CPUs to interface with high-performance peripheral devices through a data bus as wide as 64 bits.  This makes PCI at least twice as fast as the 32-bit VLB standard used on most 486's, and even faster depending on the allowable clock speed.

PCI also offers the potential of being a cross-platform standard, since it can be used on any type of PC motherboard capable of supporting it.

PCI Version 1.0 is a 32-bit bus running at a clock speed of 33 MHz, allowing a maximum data transfer rate of 132M/s.  PCI 2.0, the more desirable Pentium standard, is a 64-bit bus running at a clock speed of 66MHz.

See also: VLB, Pentium, interface, peripheral device, platform, clock, bus


personal information manager
personal information manager (PIM)

One of a recent group of new-generation specialty databases designed for personal  record-keeping.  In the words of one anonymous journalist, "glorified phone books".  Personal information managers are generally used to store names, addresses and telephone numbers, but most are considerably more sophisticated than this, offering the ability to take notes, perform queries on the database, and in some cases even perform relatively complete bookkeeping functions for a small business or self-employed professional.

Most PIMs are essentially flat file databases devoted more to organization than relationships, but some have relational characteristics.  Examples of popular PIMs are Modatech Maximizer, Symantec Act!, Lotus Organizer, Ecco Simplicity and Time and Chaos.

See also: database, flat file database, palmtop computer


Professional Graphics Adapter,pin grid array
PGA

Pin grid array, an arrangement used for contact pins on many newer CPU chips (80386 and up) in which the pins on the chip are laid out in a grid that looks a little like a bed of nails.  This arrangement allows for easier connection of chips that need a large number of contact points with the circuit board.

Also: Professional Graphics Adapter: a graphics hardware and software standard introduced by IBM in 1984 and designed for high-end desktop publishing, graphics and CAD work, it was so advanced the graphics card used a more powerful processor than the computer itself.  The first 256-color standard, but it was so expensive that it was never widely accepted.

See also: central processing unit (CPU), 80x86, printed circuit board, 8514/A, VGA, Super VGA, resolution


pico
pico-

Prefix meaning trillionth.  Not in common use yet, but as memory gets faster it will be within a couple of years.  From the Italian piccolo for small.

See also: nano-, memory


piracy

Piracy is the act of making illegal or unlicensed copies of a piece of software in violation of the author or publisher's copyright.  Technically in the US it is a civil matter below a certain dollar value (generally believed to be around $2,000).  Piracy is a very serious issue with publishers, who believe billions are lost each year to unlicensed use of software.  In an attempt to minimize the illegal use of software, many publishers have implemented copy protection schemes at one time or another, but this has largely gone by the wayside due to the inconvenience to authorized users.

Many industry watchers believe a large part of the industry outcry over the alleged billions lost to piracy is a scare tactic, as those who routinely pirate software generally would not pay, or be able to pay, for their unauthorized copies; and those who do not understand the concept of illegal use of software are generally willing to pay for their software once they understand the concept of licensing.

See also: license, register, copy protection, Software Publishers Association (SPA)


pit

A generic term used to refer to marks made in optical media such as CDs for carrying data, a slight depression in the disk's surface about the size of a single bacteria (about a millionth of an inch square).

See also: CD-ROM


pixel
pixel (pel)

A defined area on a graphic display (computer monitor).  Most computer graphics are measured in terms of their pixel size, which varies depending on the size and type of the monitor display.  The standard sizes for IBM-compatible, Macintosh, and high-resolution Atari and Amiga displays are 480 pixels in height by 640 pixels in width.  Not to be confused with dot, which is an area on a computer screen itself…a single pixel of data can cover several dots.

See also: bitmap, line art, IBM-compatible, resolution, Atari, Amiga, Macintosh, dot pitch


PKZIP
PKZIP (extended topic)

Believed by many to be the single most common IBM-compatible software program in use in the world (excluding programs included as part of operating systems such as DOS and Windows).  Archiving software designed to combine and compress files for ease of storage and transmission.

PKZIP is the brainchild of Phil Katz, an American programmer.  He began his career by developing an archiving and unarchiving program with superior performance to the then market leader, SEA (Systems Enhancement Associates) ARC.  He named the program PKARC, but lost a suit with SEA and thus the right to use the name ARC.  He subsequently renamed the program to PKPAK, and while ARC software is now obsolete, PKUNPAK is still in wide use for processing the tens of millions of ARC-compressed files still in existence.

Katz later refined the ARC compresson routines into his own unique compression scheme known as PKZIP.  Its speed, efficiency and versatility soon made it the clear market leader.  PKZIP's supremacy was threatened for a brief time in the early 1990s by rival upstart ARJ, created by Robert K. Jung, and the free LHA program created by Haruyasu Yoshizaki.  Both offered superior compression results until the 1993 release of PKZIP version 2.x, at which time Katz' software regained  and at this writing retains  supremacy in the world of IBM-compatible file compression.

See also: data compression, archive, program, IBM-compatible


PL1

Programming language


PDM
Plasma Display Matrix (PDM)

Orange colored, high resolution, neon gas, flat screen technology used mainly in older and higher-end portable computers.  Also known as gas plasma display.

See also: liquid crystal display (LCD)


platform

Refers to either an operating system or the combination of operating system/hardware configuration which makes up a working computer; the infrastructure on which application software is used; e.g. the Mac platform, UNIX platform, the IBM-compatible platform; the Windows platform.

See also: operating system, Macintosh, UNIX, IBM-compatible


platter

In a hard disk, the physical disk itself.  Hard disks can have several stacked platters; most newer consumer models only have one.

See also: hard disk)

See also: hard disk, cluster, track


plotter

A type of printer which uses pens, or inkjet devices that function like pens, instead of actual print heads, and allows the paper or the printing device to be moved back and forth across the page to create the printout.  Used primarily in CAD applications and research for creating graphical readouts of instrument data or blueprint-type drawings.  Drum-type plotters are usually used to print instrument readout data, while flatbed plotters are generally used for CAD applications.

See also: inkjet, CAD, GPIB


Plug and Play (PNP)

Plug-and-play might have been a stock term for describing hardware or software that pops into a computer and configures itself with little or no user intervention, but Phoenix Technologies, Compaq and Intel have trademarked it and hope it becomes a way of life for PC users, another advance in IBM-compatible technology ten years after it existed on other PCs.

Plug and Play is not something that comes standard with a computer, operating system or peripheral device, a fact which has created a great deal of confusion and frustration among computer owners.  The idea behind Plug and Play is that both the BIOS and operating system will cooperate in attempting to identify new pieces of hardware (which must also meet the standard) and pre-configuring them to eliminate possibilities of conflict between devices.

See also: Intel, operating system, peripheral device, BIOS, IRQ conflict


PTP
point to point (PTP)

Programming and machining via positioning, rather than via controlled movements


poke

The BASIC programming command for inserting a specific value at a specific address in memory.

See also: peek, BASIC


poll

To check status.  Email programs are said to "poll the mail server" when they check for mail, and telecommunications programs are also said to "poll the COM port" on boot-up or when a connection is requested.

See also: port, serial port


POM

Acronym for phase of the moon.  Most often used to refer to erratic hardware or software (e.g. "The connection speed with my Internet provider seems to be POM-dependant.")

See also: Internet


port

Ports are physical addresses in PCs designed to increase the flexibility of the computer; e.g. the average personal computer has at least three hardware ports available at all times: two serial ports (usually one for modem and one for mouse) and one parallel (usually used for the printer).

Serial ports are used for devices that accept information one bit at a time.  Parallel ports are used for devices that accept information eight bits at a time and are generally faster than serial ports.  You can assign network paths to a port; for example, if you are printing to a network printer.

See also: parallel port, serial port, bus


PDF
Portable Document Format (PDF)

Adobe's specification for cross-platform document creation which contains facilities for hypertext and embedding of non-text data of many types.  Hyped as a likely winner in the race to create a true cross-platform document format.  Adobe's copyright restrictions make this unlikely in the eyes of observers who have their money on SGML as the likely winner.

See also: platform, Adobe, document, format


PNG
Portable Network Graphics (PNG)

A format for graphics images gaining in popularity and expected to replace GIF (Graphics Interchange Format) as the graphics format of choice on the Internet some time in 1996/97.

See also: format, image, Graphics Interchange Format (GIF)


PSL
Portable Standard LISP (PSL)

A transportable version of the LISP programming language designed for cross-platform use.

See also: LISP


portrait, landscape

Refer to the orientation of printout.  Portrait orientation indicates that the page is meant to be viewed and/or read with the longest edge vertical, and this is the normal printing method.  Landscape orientation is most frequently used with charts and graphics which either look odd or simply do not fit standard page widths.

See also: desktop publishing


PostScript

Programming language developed by Adobe for the purpose of allowing documents, graphics and printer data to be portable across several platforms.  Extremely rich and complex.  Most users tend to use PostScript filters and compatible devices rather than program in the language itself.

Encapsulated PostScript (EPS) is a file format which allows embedding of fonts, graphics, printer definitions and other data directly into a file which can be transferred from one computer platform to another, also developed by Adobe.

Also: refers to printers capable of printing PostScript files.

See also: Adobe, Adobe Type Manager, platform, font, Page Description Language (PDL)


Point Of View
POV

Chat abbreviation for point of view

Also: Persistence of Vision: a popular freeware raytracing graphics package.

See also: freeware, raytrace


power conditioner

An electronic device designed to smooth out inconsistencies in electrical circuits by filtering line surges, spikes, drop-outs, and line noise to improve consistency and safety in computer performance, particularly in areas prone to inconsistent electrical power.

See also: line surge, dirty power


power on self-test (POST)

This is the internal diagnostic routine a personal computer undergoes each time it is turned on.  Some parts of this routine, such as memory integrity checks, are visible onscreen as the diagnostic is run.  Among the tests run are a functionality test of the motherboard, CPU, DMA controllers and interrupt controllers, floppy and hard disks, and keyboard.

See also: motherboard, central processing unit (CPU), direct memory access (DMA), interrupt


PowerPC

A hardware standard codeveloped by IBM and Apple and intended to be the next generation in personal computing.  PowerPC permits personal computers to use RISC CPU chips which can be adapted relatively easily (at least compared to the much more common CISC-type CPU chip) to run several different operating systems, not just the operating system for which the hardware was designed.

Still in its infancy, PowerPC has suffered from poor performance when emulating different operating systems (the SoftWindows software for running Windows on the Apple PowerPC runs at an extremely poor pace), high cost and a tendency by its manufacturers to release the products with known performance deficiencies.  Still, the concept appears to represent the future of personal computers, as it holds the potential of being expandable for parallel processing.

See also: IBM, Apple, RISC, CISC, central processing unit (CPU), fifth generation computer, parallel processing


PPM

Pages per minute: printing speed measurement

Also: parts per million: usually used to measure impurities


print resolution

A measure of the clarity and accuracy of a printer.  Print resolution is measured in dots per inch.

The average laser printer can produce an image with 300 to 360 dots per inch vertical and horizontal, which is virtually a perfect image to most viewers.  Inkjet printers can produce images nearly this fine, but because of the tendency for liquid inks to smear and blot, inkjet printouts at 300dpi do not appear as crisp as laser printouts.  Dot matrix printers generally produce images at a resolution of about 150 to 200dpi.

Because printers tend to have different vertical and horizontal resolutions, the print resolution of a particular model is often given as two numbers.  The best inkjet printers are capable of 600x300dpi, and high quality lasers can print 600x600dpi.

See also: dot matrix printer, inkjet printer, laser printer, screen resolution


PCB
printed circuit board (PCB)

A circuit board with electrical connections via conductive material called a trace on the board itself.  The conductive material is usually copper and the board itself is usually made of fiberglas.  In recent years the demands of modern microprocessors for more connections with other parts of the circuit has resulted in the development of circuit boards with sandwich construction, in effect several thin circuit boards  each with its own set of traces  combined together to form a single, solid unit.  Sandwich construction is used for the manufacture of PC motherboards and most daughterboards now as well.  The printing is accomplished by taking a layer of fiberglas covered completely with a coating of copper and burning off or dissolving the unneeded copper to leave only the desired trace pattern.

See also: integrate, integrated circuit, trace, motherboard


printer font

Printer fonts are fonts encoded into the printer's hardware, usually in a small (or, in the case of better laser printers, quite large) area of ROM memory.  Most dot matrix and inkjet printers contain four and occasionally six printer fonts: Times, Courier, Orator, and a fourth sans serif typeface, either Helvetica or a look-alike font.  These fonts are accessible either through the front panel or through software commands (control codes).  Newer scalable fonts such as TrueType don't make use of these built-in fonts, and most users never need them except for printing plain text documents.

See also: serif, dot matrix, inkjet, read-only memory (ROM), control codes, scalable font, TrueType, Adobe Type Manager


program

A set of binary instructions executed by a computer for a given purpose, also the act of creating a set of binary instructions for execution.  Alternatively, from the Jargon File: "A magic spell cast over a computer allowing it to turn one's input into error messages."  As opposed to data, which is the raw material for programs to mangle and destroy.

See also: binary, execution, application, utility, applet


program group

In Windows 3.1, a program group is a collection of applications or runnable documents which are combined together into a single group for organizational purposes.  Within Program Manager, they appear grouped in a single group window, or represented by a group icon which can be expanded into a window.

See also: associate, icon, application, document


program information file (PIF)

A file used for printing and plotting with early PC's; the term now refers usually to configuration files used by Windows, OS/2 or DesqView to control  the execution of DOS applications.  Among the information PIFs store are the program's window size and font, the amount of memory and processor usage it is permitted and how much it is allowed to interact with other OS/2 or Windows programs.

See also: property sheet, shortcut, multitasking, execution


plc
Programmable Logic Controller (PLC)

A microprocessor-based device capable of controlling multiple functions.

See also: microprocessor


POS
Programmable Options Select (POS)

A method used by both IBM MicroChannel and the Apple NuBus systems (used on the Macintosh) to attach peripheral devices into their bus systems.  It's a jumperless, switchless, essentially plug-and-play system for setting up hardware and assigning IRQs and addresses.

See also: IRQ, jumper, MicroChannel Architecture, Plug-and-Play


PROM
programmable read-only memory (PROM)

A type of memory chip which is designed to be encoded with specific data on a one-time-only basis.  EPROMs are erasable PROMs which can be reused.  PROMs are not commonly used in PCs.

See also: EPROM, chip, non-volatile RAM (NRAM)


Programmed Data Processor model 10,11,20 (PDP-10)

The PDP-10 was the machine that made timesharing real, but the PDP-20 was the most famous computer that never was.  PDP-10 computers running the TOPS-10 operating system were labeled "DECsystem-10" as a way of differentiating them from the PDP-11.  The DEC PDP's are the most fabled and revered of all computers among hackers and computer historians, moreso than even the more famous UNIVAC vacuum tube computer.  [Source: The Jargon File 3.0.0]

See also: third generation computer, mainframe, hacker, Digital Equipment Corp. (DEC)


PILOT
Programmed Inquiry Learning Or Teaching (PILOT)

IBM command-type authoring language for computer assisted instruction.

See also: CBT


PROLOG
Programming in Logic (PROLOG)

An artificial intelligence programming language developed at University of Marseilles; used in Europe/Japan.

See also: ESPROLOG, LISP, artificial intelligence (AI), neural network


prompt
prompt (command prompt)

Prompts, in DOS and Windows, are your computer's way of asking "What now?"  At a prompt the user is expected to either enter a typewritten command or select an item from a menu.

The DOS prompt typically looks like this:

C:\>_

Also, Internet-related: UNIX command prompt or position where you are expected to enter typewritten or menued commands.

See also: Internet, command interpreter, UNIX, menu


propellerhead

Synonymous with "computer geek" or lover of computers and/or programming.  Stems from the prototypical stereotype (now there's a buzzword) 1960s image of enthusiastic computer programmers as overgrown kids wearing beanie hats with propellers on the top, a stereotype which has never been too far off the mark.

See also: hacker


property sheet

A complex dialog screen used in Windows 95 and OS/2 to configure various options and properties of an object, which could be a document, program or shortcut.

See also: program information file (PIF), shortcut


proprietary

Strictly speaking, "property of the proprietor".  Used in computing to indicate that a specific piece of software or hardware is the design and property of a particular manufacturer or publisher.  Examples of proprietary hardware are MicroChannel Architecture (MCA), used on IBM Personal System/2 computers and either little used or not used at all on other systems.

Proprietary systems are disliked by most veteran computer enthusiasts since the general feeling is that the use of proprietary systems, hardware or software is an attempt to impose a standard on the industry and thus on the consumer.  Unfortunately, with many specialized programs and components, the proprietary option is the only game in town, since they are usually covered by patents or copyrights.

See also: MCA, IBM


protected memory

Protected memory is a feature of 80x86 processors (80286 through Pentium Pro) that permits multitasking.  It essentially protects an area of memory in use by one program from being accessed by another and compromising the integrity of the system.  DOS and Windows use different specifications for managing this protected memory, but both must make use of the capabilities inherent in the chips themselves.

See also: DPMI, multitasking, 80x86, Pentium, real mode (DOS)


PD
public domain (PD)

Refers to a work whose copyright has either expired over time or been released to the public by the copyright holder.  Property of the public; freely usable in any otherwise legal form.

See also: shareware, freeware, license


PCM
pulse code modulation (PCM)

A method of encoding analog (usually audio or video data) into digital form for transmission either through network connections or (usually) through computer subsystems for processing.  PCM encoding is the method most often used for converting audio data into sampled sound for processing with synthesizers, and is also used in the video industry for converting screen data to digitized graphical data.

See also: analog, digital, synthesizer, sample


QEMM
QEMM (Quarterdeck)

QEMM is the most popular product offered by the American software firm Quarterdeck, and stands for Quarterdeck Expanded Memory Manager.  This was and continues to be an important tool for maximizing and enhancing the use of much more than just EMS expanded memory with machines that depend upon DOS-style memory management (based on the 640K upper limit of conventional memory).  Much loved by its users and considered to be the premier product in its field.

Quarterdeck also developed DESQview, software which permits multitasking under plain DOS.

See also 386MAX, expanded memory, conventional memory, memory manager, multitasking


quarter-inch cartridge tape (QIC)

The standard width, or format, used by tape cartridges for popular tape backup systems.  Although the width never varies, tape backup cartridges have variations in quality just the same way audiocassettes do.  At the bottom end of the scale are low-capacity 40Mb tapes designed for older units, and many newer consumer units have capacities for cartridges of similar size of up to 750Mb, more than a CD.

See also: tape backup, format, mag tape


query by example (QBE)

A type of search request procedure, most commonly used with databases, that allows the user to search for a type of data based upon an example supplied to the computer.  The parameters for current use of QBE were apparently first set forth by M. Zloof of IBM in the late 1970s and are now in wide use in dBASE IV, Paradox, and have their most exciting implementations in SQL-compatible databases.

See also: database, dBASE, Borland Paradox, SQL, note also that M. Zloof in reverse is Foolz M, a rather strange finding we were unable to resolve at presstime.


QMF
Query Management Facility (QMF)

A module usually used on larger database systems to handle the flow of queries from several connected terminals or workstations.

See also: database management system (DBMS), terminal


queue

A lineup of data awaiting processing.  Usually refers to a group of files waiting to be copied to a backup storage medium such as tape or printer data files waiting to be sent to the printer.

See also: cache, network, backup,


quick format

An effective method for erasing disks containing large numbers of files or directories.  Deletes the critical areas of the disk but does not rewrite the formatting of the disk, which can prolong the disk's useful life.  Practical only with floppy disks.

See also: floppy disk, format


Quicken
Quicken (INTUIT)

Created by INTUIT software, the world's most popular home accounting package for DOS and Windows.  Also publishers of Quickbooks, a popular business accounting package.  Both products were sold to Microsoft in 1994 and resulted in an FTC investigation that resulted in Microsoft being forced to sell one of their accounting software lines.  (Microsoft Money was viewed at the time as the major competitor to Quicken, leading to a finding of restraint of trade against Microsoft.)

See also: FTC, spreadsheet


QWERTY or Sholes keyboard;Dvorak keyboard
QWERTY or Sholes keyboard,

Dvorak keyboard

QWERTY is named for the first six keys from the top left of a standard English-language keyboard.  QWERTY keyboards were originally designed to slow down typists to prevent the pressing of two keys simultaneously which jammed the mechanism.  The layout was specifically engineered for English-language typists to force the maximum amount of finger movement between keypresses.

QWERTY layouts are no longer needed in the days of touch-typing and low-tension sprung keypads, and most typists who spend considerable amounts of time at a keyboard find that the newer, far more efficient Dvorak layout.

The Dvorak layout was designed by August Dvorak, patented in 1936 and approved by ANSI in 1982.  It is a much faster, more comfortable and less error-prone keyboard layout and some firms require their employees to use it.  Dvorak is the layout with which most world typing speed records have been set.

Dvorak layouts are available as an option with DOS and Windows, and while it essentially forces the user to relearn their typing style, it is both more efficient and less stressful on the hands and wrists, reducing the likelihood of repetitive strain injury.

See also: repetitive strain injury (RSI), ergonomics


R/W

Read/write


RADAR

Radio Detecting And Ranging


radio button

A small button used in Windows, OS/2, Macintosh System and other graphical operating systems for selecting options.  It usually looks like a small circle the size of the text next to it.  Radio buttons are so named because they are designed to appear similar to buttons used on radios and stereo equipment.  A radio button is a switch, meaning it can be on or off, and if used in combination with other radio buttons, it also means that only one radio button in the list can be used.

See also: check box


Radio Frequency Interference (RFI
Radio Frequency Interference (RFI)

A type of electromagnetic radiation that occurs in the spectrum reserved for radio and television broadcasts and which interferes with these signals.  Because this radiation can disrupt emergency communications, air traffic control and other essential services using broadcast bands, the US Federal Communications Commission (FCC) closely monitors computer hardware for compliance with emissions limits known to be non-disruptive, and issues certification for hardware falling within these limits.  The worst violators for RFI are the computer's crystals, which will vibrate at rates within RF frequency ranges, but electrical transformers and power conversion units can also emit significant amounts of RFI.  Computers are usually required to have RF shielding, which usually consists of grounded metal completely surrounding the motherboard, before they pass FCC muster.

See also: extremely-low frequency radiation (ELF), electromagnetic radiation (EM), Federal Communications Commission (FCC), MPR II, dirty power


Random Access Memory (RAM)

The basic term for the chip memory used on all computers for running programs.  The "random" comes from the fact that RAM chips are designed to be accessed at any point by the CPU with virtually the same amount of speed.  The 500,000th bit of a one megabit chip can be accessed just about as quickly as the first bit.  RAM differs from ROM (read-only memory) in that RAM can be erased and rewritten thousands of times a second whereas data in ROM is permanent.

See also: central processing unit (CPU), memory, dynamic random access memory (DRAM), static RAM (SRAM), read-only memory (ROM)


raster

In computing terms, a graphical line usually represented by a solid bar of color one pixel wide extending from the top of the screen to the bottom, or vertically between two fixed points.  Rasters are among the most primitive methods used for rendering graphics but still useful for some applications.  The color bars seen on a TV test pattern are the most common examples of rasters.

See also: bitmap


raytrace

Raytracing is the graphic design mode most people associate with computer-generated animation.  It is an extremely sophisticated system of developing and rendering (drawing) images based on mathematical formulae and relationships between lines.  It can incorporate elements of CAD, line art, scalable fonts and other types of graphic design.  Raytracing derives its name from the fact that the process relies on the motion and manipulation of lines (rays) and curves for creating images.

Raytracing has been in use on PCs for over a decade and on minicomputers for twice that long, and is expected to be the method of choice for computer-generated animation for many years to come.  The primary reason for this is that computer hardware has yet to catch up with the math-intensive operations used by raytracing software, and many of the capabilities of this extremely versatile graphic design technique have yet to be fully exploited.

 See also: bitmap, line art, Persistence of Vision, wire frame, CAD, virtual reality, AutoCAD


read-ahead

A function of disk caches in which the cache program reads several sectors beyond where the user requests at a spare moment when the system is not busy.  It does this as a means of making the next request for data go that much more quickly.  Read-ahead caching is used primarily for CD-ROMs to improve their performance, especially with graphics-intensive applications and games.

See also: cache, CD-ROM, disk cache


ROM
read-only memory (ROM)

Computer memory available for reading only; data contained in these chips is burned in and cannot be changed.  In 386 or newer computers this information is usually copied to RAM when the computer is started for increased system performance.

See also: random access memory (RAM), Shadow RAM, ROM-BIOS, memory, chip, EPROM


RWM
read/write memory (RWM)

Continuously changeable memory; RAM is r/w memory.  Rather archaic.

See also: random access memory (RAM), read-only memory (ROM), PROM, EPROM, memory


readme
readme, README files

According to many veteran computer users, these files are so named because people won't read them.  These are text files containing important information either included with a software package or left in the root directory of an Internet FTP site for the benefit of users.  Not intended to be ignored or chuckled at…but to be read.  In the case of shareware and freeware software, the README may be the only documentation available for the program.

See also: Internet, ASCII, text file, shareware, freeware


real mode
real mode (DOS)

A virtually obsolete term referring to the way a PC's operating system runs programs.  Real mode is essentially a "backward compatibility" mode, which forces 80286 through Pentium Pro computers to emulate the limitations of an 8086 PC/XT.  Real mode permits the use of only one megabyte of memory to be addressed and allows only one process/program to be run at one time.  This actually has advantages in some instances because this dedication of the computer to one process frees all of its resources (except memory above 1Mb) for the use of that program.  MS-DOS is a real mode operating system, and Windows stopped offering real mode operation beginning with version 3.1.

See also: backward compatibility, DOS Protected Mode Interface, emulation, IBM PC/XT, operating system, multitasking, real mode (Windows)


real mode (Windows)

A mode of operation used by Windows versions 3.0 and previous, obsolete with Windows 3.1 which does not permit real mode operation.  The term is almost never used or mentioned today in context of Windows.

Real mode allowed Windows version 3.0 or lower to run compatible Windows programs using only the first 640k of DOS memory.  The memory overhead required by Windows 3.1 made real mode unworkable, and it is only useful for antiquated XT's and 286's incapable of any other form of Windows operation.

 See also: 386 enhanced mode, standard mode, multitasking, IBM PC/XT, 80286, boot, Windows for Workgroups, real mode (DOS)


RTIC
real time interface connector (RTIC)

An adapter card for real time device interface.

See also: adapter, RT, peripheral device


record

A group of information about a specific item or subject and stored in a database is referred to as a record.  A record can be as simple as a name and phone number in a personal phone book database or as complex as a complete personal medical history in a hospital database.  Records do not necessarily need to be sequential or defined by any particular ordering or numbering scheme.  Records are not files unless each individual record in a database is stored or opened as an individual file.  See also: database, flat file, relational database


RISC
Reduced Instruction Set Code (RISC)

Usually describes the architecture of a newer type of processor chip which most feel is the next step in personal computer CPU chips; fast, flexible and versatile.  RISC chips, due to the low number of restrictions placed on how they can behave, can essentially be configured by software to perform a wide range of functions.  This type of chip was usually confined to use in high-end workstation computers such as the Sun workstations, but with the advent of the PowerPC has found its way into personal computers.

See also: Sun Microsystems, CISC, PowerPC, central processing unit (CPU), microprocessor


refresh rate

Characteristic of a computer monitor; number of times per second it redraws the screen contents.  Generally speaking, the higher the refresh rate, the less stressful the monitor is to work with.

See also: resolution, dot pitch, interlacing, flicker


register

A register is an area of ultra-fast memory within a processing chip (usually the CPU) used for storing information about the specific instructions, memory usage and other critical information about a program.  It is in a sense like a registration desk where the program provides information about itself so that a programmer can deduce problems with a program's function or information about its performance.  Registers are primarily used in assembly language programming.  See also: assembly, address, central processing unit (CPU), stack


registry

Windows 3.1 used a registry to keep track of which programs owned - or could own - certain file types that could be used in programs other than the programs which created the files (OLE and DDE).  Windows 95 now uses the registry to keep track of an enormous range of data, everything from the hardware configuration to the color scheme of the desktop.  This information was stored in text format in Windows 3.1 and could be accessed using Notepad.  The new registry is a binary file that requires its own special editor and considerably more understanding of the workings of the operating system.

See also: Object Linking and Embedding (OLE), Dynamic Data Exchange  (DDE), SYSTEM.DAT


relational database

A type of database in which changes made to one file can affect the contents of others, or in which changes made to the whole system can affect individual files.  A payroll system which accepts tax data is an example of a relational database, since changes to the tax information will affect all employees' records.

See also: flat file database, database


removable cartridge drive

A durable type of hard disk that allows the disk itself to be removed and transported from place to place.  Cartridge hard disks allow for much higher copying speed than floppy disks (but lower than normal hermetically-sealed hard disks) and much higher capacities (but once again still lower than sealed hard disks).  The two most common types today are the Syquest 44Mb and 88Mb removable drives used most often in the music and graphics industries, and the Iomega Zip drive, an inexpensive, removable 100Mb drive used by many consumers as an alternative to tape and floppy disk backup.

See also: floptical drive, hard disk, tape backup unit, rewritable optical storage, magneto-optical storage


repetitive strain injury (RSI)

Exactly what it would appear to be: injury which occurs as a result of repeated strain to the same tissues (bones, muscle, skin, etc.).  RSI is used specifically in terms of computing because of the high risk of RSI faced by those who work with computers on a daily basis.  The simple act of typing on a standard QWERTY keyboard places strain on the hands and wrists, which is worsened by improper wrist, elbow and shoulder support.

The result of long-term repeated strain is injury to the wrists, hands or shoulders, and there are many varieties of RSI suffered by typists and computer operators.  It is believed the most common is tendosynovitis, inflammation of tendons in the wrist which results in pain in the hands and forearms.  Less common, but far more publicized, is the crippler carpal tunnel syndrome, in which actual physical damage has been done to the wrist.

RSI's can be avoided or reduced in severity through the use of proper typing and mouse posture, supports to the hands, wrists and shoulders, frequent breaks, and according to recent reports, vitamin B6 as a treatment for inflamed nerve endings.

See also: carpal tunnel syndrome, ergonomics


resolution

Resolution in computing terms is a measure of clarity and sharpness, and is applied to both printers and video displays.  The two types of hardware use very different methods of measuring resolution; see the individual definitions for details.

See also: print resolution, screen resolution


restore, restore button

Two common meanings.  Most often used to refer to manipulating the size and shape of a window.  The restore option, available from the control menu in the upper left-hand corner of a window, returns a window to the state it was in before it was last resized, minimized or maximized.  Restore also refers to the process of replacing data from a backup.

The restore button refers to a small button in the upper right-hand corner of a window.  In windows 3.1/3.11, it has two small up and down pointing arrows, while in Windows 95 it looks like two tiny windows overlapping each other.  Clicking this button restores the window to its previous size and saves a click over using the Restore option in the control menu.

See also: control menu, minimize, backup


RPM
revolutions per minute (RPM)

A measurement usually used with floppy disks, hard disks and CD-ROM drives.  Usually has nothing to do with the actual performance of the unit itself.

See also: floppy disk, hard disk,harddisk CD-ROM


rewritable optical storage

CD-ROM and magneto-optical disks are examples of rewritable optical storage, although rewritable CDs as of late 1995 were not yet a practical reality.  These technologies employ encoding of information onto thin films of either magnetic or amorphous crystalling material, and the data is read back using lasers rather than the magnetic read/write heads used by most common storage media.  Rewritable optical storage suffers from slower speeds than magnetic storage but offers the benefit of high capacity at low cost and removability, since rewritable optical media do not need to be hermetically sealed to hold large amounts of data, but merely be well-protected physically.

See also: magneto-optical storage, CD-ROM


REXX

REXX is a simple programming language created by M. F. Cowlishaw in 1979 and first exploited by IBM with its OS/2 operating system.  It is now a full-fledged operating system designed to be used with DOS, Windows and OS/2 which provides an entree into programming easier for novices than BASIC (although also less powerful).  It can be coded as simply as batch files and can be as complex as many BASIC programs, providing a needed intermediate level between the oversimplicity of batch and the now-baffling complexity of modern BASIC.

See also: batch, BASIC, OS/2


RFTDCA

Revisable-Form Text Document Content Architecture: the old IBM Displaywrite/370 text document format; still in use and supported by most commercial word processors due to the enormous number of documents created in this format.

See also: word processing, document


RIA

Robotics Industries Association


routine

A routine is a sequence of instructions issued by a program with a beginning, a middle, and an end, that does not necessarily need the rest of the program to function.  For example, the display of this topic by Windows Help is a routine, and it could be accomplished as a separate, much simpler program if it was all that was necessary for the program.  Most usable software is composed of groups of routines, which are also referred to as subroutines.

See also: macro, program


RO

Read only


robotics

The science and study of the behavior of machines as they compare to human behavior; also the development of machines with human-like behavior characteristics.  In a sense, all computer study is a form of robotics.

See also: artificial intelligence, neural network, RIA


ROM-BIOS

Read Only Memory-Basic Input Output System: IBM-compatible program code which is permanently etched in computer memory.  This data manages the essential input/output systems in the computer.  It usually operates transparently, meaning that the user should never see or have to configure this information once the computer is set up and all hardware components are installed.

See also: read-only memory (ROM), random access memory (RAM), IBM-compatible, EPROM, Shadow RAM


RPG
role-playing game (RPG)

A type of interactive game, not necessarily computer-based, in which the player assumes the identity of a character in the game for the purpose of play.  Dungeons and dragons is the stereotypical RPG, but the definition extends to cover interactive games of many types including Leisure Suit Larry, Police Quest, Zork and Where in the World is Carmen Sandiego.

See also: Zork, virtual reality


root

The top level of a disk drive or directory structure.  In DOS, C:\ is considered to be the normal root on the vast majority of PCs.  Root can also refer to the directory to which a user of a shared computer system is directed to automatically upon login regardless of where that directory might be on a particular computer.

See also: directory structure


RPG11

Programming language


RS-232
RS-232, RS-232C

The standard specification for serial ports on a personal computer.  This standard specifies how pins on serial and parallel cables are assigned and the engineering of the cable and connectors.  RS-232 is the standard most often used for serial port connections, and the C stands for Centronics, who developed the current specification for parallel port transmission.

See also: parallel port, serial port, Centronics


RSN
RSN (real soon now)

A theoretical unit of time used primarily by software manufacturers to indicate when a given product will be released or ready for release.  As in "The new version of Windows is coming RSN…the January 1994 issue of ComputerPhobes Digest said so."

See also: vaporware, FUD


RT

RISC Technology: IBM-PC using UNIX-based AIX operating system and RISC processing chip.  (RISC technology is now available on PCs, e.g. PowerPC)

Also: RoundTable: usually used to refer to discussion groups or fora on the GEnie online information service.

Also: real time: indicates that events measured or described as RT are happening in a non-simulated time base or are not delayed until a later time.

See also: RISC, UNIX, AIX, operating system, PowerPC


Run Length Limited (RLL)

A type of encoding scheme used with older MFM hard disks for increasing the amount of data storage on the hard disk.  The most commonly used format was ARLL (Advanced RLL) which gave an RLL-certified hard disk roughly double the storage capacity in the same physical space as a similar MFM hard disk.  In addition to the higher capacity, RLL encoding also permits higher speed.  RLL hard disks still functioning today can also be used with standard MFM controllers but will not get the benefits of the increased speed and storage offered by RLL.

See also: MFM, IDE, hard disk


runtime library

A program or, in dynamic operating systems such as OS/2 and Windows, a library of code which is required by another program in order to function.

As an example, several thousand shareware and freeware Windows programs require a Visual Basic code library called VBRUN300.DLL in order to function.  Since this code is only needed while the program is running and ceases to be needed by the system when it stops, it is known as a runtime library.  Similar libraries exist for Borland C++ (BWCC.DLL) ToolBook (TBK.EXE among others) and other programs.  Technically speaking, this lexicon needs the WINHELP.EXE program as a runtime library in order function interactively.

See also: command interpreter, Visual Basic, C++, Borland, shareware, freeware


SAGE

SAGE, not UNIVAC, was the world's largest first-generation vacuum tube computer.  It was used by the US Air Force in the 1950's.

See also: first-generation computer


sample

Generally refers to audio data.  A sample is a digitized copy of a waveform in real time, for example a piano note or a voice, saved in a standard digital sound format.  Samples are used as the bases for constructing new sounds with synthesizers or as sound effects for the PC.  The familiar "ta-daa" heard when starting Windows with a sound card is an example of a sampled sound, and interestingly enough, it's a sample of a synthesizer which in turn is mimicking an orchestra, a strange technological turnabout.

See also: pulse code modulation (PCM), synthesizer


SAS

Statistical Analysis System


scalable font

Scalability allows for fonts to be drawn to precise proportions - or rendered - regardless of their size because they are encoded as collections of lines and curves rather than specific groups of pixels.  Bitmapped fonts suffer from "jaggies" while scalable fonts do not.

See also: TrueType, font, bitmap, vector graphics, jaggies, typeface


scanner

A peripheral device designed for making digitized copies of printed matter.  Usually scanners are used to capture graphical data such as hand drawings or magazine graphics for use in computer applications, but scanners are also frequently used to scan old typewritten or published documents for the purpose of converting the text to digital text data.  There are four basic types of scanners.  Hand-held scanners are the most common for consumer use.  Sheet-fed scanners are becoming increasingly popular in business for scanning and converting data such as invoices and letters.  Flatbed scanners are used in most graphics houses because they will also scan inflexible objects such as boxes and larger objects such as newspaper pages without feeding them through a sheet feeder.  Flatbed scanning is also the type of scanning used by photocopy machines for capturing the image to be copied.

Overhead scanners function almost like scanners and are almost exclusively reserved for higher-end commercial graphics applications.

See also: optical character recognition, peripheral device, TWAIN, laser printer


screen capture
screen capture/screen grabber

In DOS: software that captures all the text appearing on your screen for printing or saving as a disk file; in Windows: software that captures all or part of the current screen including graphics for printing or saving as a disk file.

See also: buffer, file


screen resolution

A measure of the clarity and accuracy of a monitor or software video driver.  Screen resolution is measured in pixels, so the clarity depends on the size and quality of the monitor.  The screen resolution of a particular type of graphics adapter card only indicates its potential, not how good it will actually look.  To make matters more confusing, a single standard can have several resolutions.  SuperVGA, for example, can produce resolutions of 800 pixels wide by 600 high, or 640x480.  CGA, EGA and VGA also have different screen resolutions available.

Generally speaking, the higher the screen resolution, the fewer colors are available to display onscreen due to the higher memory requirements of a sharper screen display.  Increasing screen resolution does not sharpen the image, however.  What it does instead is permit more image area to be displayed on the screen at one time.

See also: CGA, EGA, VGA, Super VGA, pixel, dot pitch, refresh rate, print resolution


screen saver, screen blanker

A piece of software designed to prolong the useful life of a computer monitor by monitoring computer activity and altering the display when no activity is detected for a period of time.  Screen savers usually monitor mouse and keyboard but can also be configured to watch printer and modem as well.

The most elementary form of screen saver is a screen blanker, which simply replaces the image on the screen with a blank screen until activity at the monitored devices is detected.  Screen savers can be extremely sophisticated, and some, such as Razzle Dazzle and After Dark, have become popular "toy" programs in their own right.

Screen savers prolong monitor life by preventing fixed objects on a screen, such as a window which stays in a fixed position for a long period of time each day, from "burning into" the phosphor at the front of the monitor until the image becomes a permanent part of the display.  This effect can be seen most vividly on old coin-operated video game units, but the greenish color on older television sets is also a result of burn-in.


script

Series of instructions, usually text, used to control the processing of data by an application; usually refers to user-generated instruction sets.  AUTOEXEC.BAT and WIN.INI are examples of scripts.  Macros are also referred to as scripts, although not all macros require scripted text files in order to function.

Scripting is also a term used to refer to programming in languages such as PERL or BASIC that use interpreters to process instructions rather than building compiled binary executables.  Many telecommunications programs include their own scripting languages.

See also: runtime library, command interpreter, batch, macro, BASIC, compiler, execute


scroll, scroll buffer

The act of moving back and forth or up and down through a "virtual window" (a window whose contents are not all visible on the screen at once) is known as scrolling, so named because it is an effect similar to the one achieved when reading a scroll.  A great many Windows programs utilize scrolling, but the most common example of scrolling is the DOS command line.  When the commands or data displayed onscreen appear to have disappeared off the top of the screen, that data is lost from view forever.

For this reason, many "power users" load a small TSR program designed to capture this buffer to a text file (or save it in memory where it can be reviewed) so they have a ready reference to information DOS would not otherwise make available.  Windows uses its own scroll buffer for data in "virtual windows", and the way this buffer functions varies depending on the program using it.

See also: buffer, TSR, command prompt


second generation computer (2gc)
second generation computer

Second generation computers are classified as those in use from the late 1950s to the early 1960s, the first transistorized units and the first to use disk-based storage as well as tape.  The IBM 1401 and the Honeywell 400 are examples of second generation computers.

See also: first generation computer, third generation computer, fourth generation computer, fifth generation computer


sector

A sector is a fraction of a track, and the smallest physical measurement of disk usage.

All files are assigned specific sectors on which they can store their data, and while a file can share part of a track with another file, it cannot share free space in a sector.  While tracks are laid out on a disk like rings on a cut tree trunk, sectors are laid out like sections of a track, somewhat similar to divisions on a clock face.  The standard size for sectors on floppy disks is 512 bytes, or an area one ninth of one of the eighty tracks on a 1.44Mb floppy.  Most hard disks have sector sizes of 2,048 bytes, but this size can vary depending on the type of formatting and data access used.

Sector can also refer to a division of a given area, such as a part of a playing field or three-dimensional representation, and the sector is usually represented by its x, y and (3D only) z coordinates.

See also: cluster, track, file, x-y axis


self-extracting archive (SFX)

A compressed archive which has been specially processed to turn it into a runnable program.  The procedure adds a small amount of code to the start of the archive file so that it can be extracted and used by the end user without the need for a local copy of the necessary decompression software.

Long shunned in telecommunications because of the ease with which viri and trojan horses could be attached to the executable code, SFX's are rapidly becoming the preferred form for distribution of software via Internet, and particularly for Microsoft Windows, because of the ease of use of this particular type of file.

See also: data compression, archive, PKZIP, virus, trojan horse, Internet, execution


semaphore

Semaphore relates back to the flag-waving code used in navies for centuries and refers to a "flag variable" used to indicate whether resources shared by more than one application, or more than one process in the same application, can be used by another or whether it will have to wait.

Semaphores are critical for multitasking operating systems such as OS/2 and Windows 95 which directly share the use of the processor chips.  They are less critical with Windows 3.1 which is a time slice multitasking system.  Windows 3.1 does not often need semaphores since each time slice is owned by a specific program, which uses its time and then passes control of the operating system to another program until its turn comes up again.

See also: multitasking, multithreading, time slice, OS/2, share, attribute


semiconductor

A semiconductor is not, as is commonly believed, an actual electronic component.  Rather it is a compound or element such as germanium or silicon which conducts electricity very poorly at low temperatures but becomes more conductive with the application of energy in the form of light, heat or electricity.  This ability to conduct or not depending on external circumstances makes this type of material function in much the way as a basic vacuum tube and forms the basis for virtually all modern electronics.  Semiconductive materials are what make transistors possible.

See also: metal-oxide semiconductor, transistor, integrated circuit


serial port
serial port (communications or COM port)

Refers to both the external sockets on a PC where peripheral serial devices such as mice, modems and printers are connected and to the physical bus addresses in the computer where serial communications data enters and exits the processing system.

Serial ports are one-bit physical connection points on a computer designed for connecting devices requiring longer cable runs than parallel ports.  The fact that data does not travel eight bits at a time as it does with parallel ports means there is less chance of the individual signals interfering with each other over longer distances.

Serial ports, like parallel ports, use the RS-232 standard interface (usually a 23-pin or, in the case of most mice, 9-pin connector), but do not use the Centronics standard for pin layout used with parallel ports.  Modern PCs have four COM ports, of which only two are normally available.  Newer PCs permit access to all four without hardware modifications.

See also: bus, port, parallel port, Centronics, RS-232, modem


serif
serif, sans serif

Serifs are the ornamental flourishes on characters used in some typefaces (from the Dutch schreef, to stroke).  Sans serif refers to a typeface which does not have these flourishes (from the French sans, without).  Serifs originated with the craft of bookmaking as a means of adding an artistic touch to printed characters, but serifs are widely viewed today as a hindrance to readability.

Times Roman, the newspaper-style typeface used by Windows, is a serif typeface.

Arial, the typeface used for this help tool, is a sans serif typeface.

See also: font, typeface, dingbat


SFT

System Fault Tolerance.

See also: mean time between failures (MTBF)


Shadow RAM

A type of hardware interface that allows data stored on ROM chips, such as the video card's internal software and the computer's BIOS information, to be loaded into much faster RAM memory during the boot process.  These areas of memory are then reserved for this particular software and the operation doesn't have to be repeated unless the hardware configuration is changed or the computer is rebooted.  The difference in speed is obvious to anyone who turns off Shadow RAM from the hardware configuration menu available at boot, especially with graphics and disk-intensive applications, and Windows is both graphics and disk-intensive.

See also: random access memory (RAM), read-only memory (ROM), boot, BIOS, upper memory area (UMA), boot


share

SHARE.EXE is a program used by DOS to manage open files.  It is designed to insure that a file in use by one program cannot be opened and modified by another program.  This is essential in networks where several people might try to work on the same file and only one person's changes would be recorded, and handy in multitasking operating systems for preventing confusion between multiple copies of the same file open in different programs.  Locked file sharing is also implemented in Windows with a device driver that does the job of SHARE.EXE.

See also: locked file, file handle, file control block


shareware

A method of software distribution developed in the early 1980s as a means of allowing free distribution of commercial-quality software on BBS', online services and via low-cost disk sales which allows the author to still be paid for their work.

Shareware originally meant any software offered expressly to be shared between users but has since become a term synonymous with try-before-you-buy.  The idea is to allow the user a free trial period of the software (usually 30 days) before requiring that payment be made for the software if it is kept.

Shareware typically offers bonuses to those who pay to register a license for the software, since it is traditional not to cripple try-before-you-buy in any fashion, and without an incentive to purchase most people will not register the software.  This help tool was originally shareware.

See also: license, Association of Shareware Professionals (ASP), freeware, public domain (PD), user supported software


(cut-)sheet feeder

A mechanical device that either attaches or is permanently attached to the front of a printer for the purpose of automatically inserting precut sheets of paper (usually 8-1/2"x11") into a printer one at a time.  Used for automating the printing of forms, long documents and envelopes.

See also: tractor feed, dot-matrix printer


shell

A seashell is designed to hold the creature who lives in it and make its life easier.  In computing terms shells have pretty much the same purpose.  They are programs whose reason for existence is to make other programs easier to live with.

Shells function as interfaces or interpreters between software and hardware or software and other software.  DOS itself is a shell...a shell for the chips in a computer.  But even if you were a DOS expert, you would be totally lost if you had to communicate directly with DOS.  You would need to think and communicate in a completely different way in order to use your computer.  So DOS uses its own shell program, a program called COMMAND.COM, as an interpreter.  COMMAND.COM "traps" mistakes so that you can't bring DOS to a crashing halt by typing the wrong command at the wrong time.  It also traps the mistakes of other programs, and for exactly the same reason.  Most useful of all, it communicates, or at least tries to communicate, with you in something that might occasionally look like plain English.  [Source: First Train for the Internet]

See also: disk operating system (DOS), program, trap, command interpreter


shortcut

Windows 3.1 used icons in Program Manager as a means of allowing easy access to a menu of documents and programs on the computer.  Windows 95 extends this functionality by allowing several types of menus.  Most-used documents and programs can be run from the Start menu, launched directly from icons on the desktop, or run using a number of third-party methods including even Windows 95's own right-click menus.  All of these methods require the use of a shortcut, which is a small file which includes the name of the file to be executed, its location, and the name given to it by the user.  When the file or program is launched, the act of launching the item begins by accessing this shortcut file which then seeks out the appropriate program or document and executes it.

See also: property sheet, program information file (PIF), menu, launch, execution


shortcut key

Shortcut key is the term Microsoft uses to indicate hotkeys used within the Windows operating system.  Shortcut key is synonymous with hotkey.

See also: accelerator key, hotkey, macro


SIMM, SIPP
single inline memory module (SIMM), single inline package (SIPP)

These two acronyms refer to types of computer memory which can be added to a PC.

SIPP memory is a card-like module about three inches by three-quarters of an inch in size with several chips mounted on the circuit board and a row of (usually) 30 gold-plated pins that plug into a row of sockets on the motherboard.  SIPPs are obsolete.

SIMMs look very much like SIPPs except they have edge connectors similar to the rigid, plated edge connectors on peripheral cards.  Older-style SIMMs used in most PCs prior to mid-1994 used 30 pins; newer SIMMs use 72 pins.  It is critical to know the difference when shopping for memory.  SIPPs or SIMMs usually hold between three and eight chips, and consumer-grade SIMMs can have memory capacities ranging from a stingy 256K to a whopping 16Mb.

See also: integrate, integrated circuit, chip, dynamic random access memory (DRAM), memory


SCSI
Small Computer Systems Interface (SCSI)

Small Computer Systems Interface: pronounced "scuzzy", this was and in many circles still is considered the premier method of accessing data from fixed (hard) disks.  Extremely fast and flexible, and used on most personal computer platforms, it allows multiple hard disks to be connected internally or externally using a daisy chain topology and is the standard in use with Macintosh, Amiga, Atari ST, and on most high-performance IBM-compatibles requiring disk-intensive operation.  Until about 1994 it was considerably more expensive than IDE hardware of similar size and performance, primarily due to its smaller market base, and remains as of this writing about 20 percent costlier per megabyte of storage than IDE/EIDE or PCI storage.

See also: IDE, EIDE, daisy chain, Macintosh, Amiga, Atari


SME

Society Of Manufacturing Engineers


smoke test

Amateur's hardware test.  When installing or repairing a piece of hardware, this term refers to the first power-on and the hope of the operator that no smoke will result from the work done.

See also: SNAFU, glitch, FUD


SNAFU

Situation Normal-all F***ed Up: military expression coined during World War II.  Passed into common usage and used either upper or lower case (snafu) as a synonym for glitch, disaster or unexpected problem, as in "This worked perfectly until some unexplained snafu caused it to stop last night".

See also: glitch, FUD, smoke test


sneakernet

Two computers networked by means of floppy disks transported from one computer to the other by the user.  A slang term for a non-networked network that requires manual file transfers of the type just described.

See also: network, floppy disk


software

Not confined strictly to computing.  Software is any kind of usable data, as opposed to hardware which is designed to store and transmit that data.  The brain is hardware; memories are software; a bruise is hardware, pain is software.

See also: file, program


The Software Publishers Association (SPA)

An organization and lobby group funded primarily by large software publishers whose main function is to raise public and government awareness about software piracy and illegal use of unlicensed software.  Believed by many industry-watchers to be a propaganda organization.

See also: piracy, license


source code

Generally refers to the text instructions created by a programmer in the process of writing software.  This text is then translated by a compiler into binary language understandable by a computer's operating system.

Also referred to simply as code; this is not strictly correct since code can mean machine code, or source code which has been compiled into an executable form.

See also: binary, operating system, compiler, execute


destdir
source/target/destination directory

Terms used in file management to refer to the relative locations of directories containing files or other directories to be moved or copied from point A to point B.  The source directory is the "point A" directory; the target or destination is the "point B" directory.

See also: file management, directory structure, directory


spawn
spawn, parent, child

Parent and child refer to the relationship between two objects in a system.  Which is parent and which is child depends on the situation.  An example of this relationship can be seen by clicking the Search button at the top of this help window.  Clicking the button will cause another window to pop up in front of this help window.  This search window is considered to be a child window of the main help window, because it could not exist if this parent help window didn't exist first.  The child window is spawned, or given birth, by clicking the Search button on the parent window.

Parent, child and spawn can refer to relationships between any sub-processes within a program or operating system, and they are used as a way of describing relationships and keeping track of what triggers what, when and how.

See also: program, operating system


line surge, spike
spike, line surge

A sharp, short-term increase in voltage through electrical circuits, feared by computer users due to the capacity of a line surge to fry electronic components.

See also: dirty power, power conditioner


SPOOL
SPOOL, spool

Simultaneous Peripheral Operations Online

Also spool: used to refer to data queued on disk or in memory for processing; i.e. a "spool" of text to be sent to the printer.

See also: buffer, cache


spreadsheet

Spreadsheet refers either to a piece of software designed to allow for virtual viewing of data, usually numerical or mathematical.  The term can also refer to a table of data created with such software, although the term worksheet is used here instead so as not to confuse the software and the data it creates.

Spreadsheets derive their name from the fact that the visible "sheet" of information can spread beyond the screen boundaries of the computer or terminal on which the data is viewed.  Spreadsheet tables might have only five visible columns or rows onscreen but have several dozen more spread to the right past the visible boundary of the monitor, and these are accessed by shifting the view of the spreadsheet to the desired columns and rows.

The most common application for spreadsheets is the organization of financial data, although they can be used for statistical analysis of virtually any kind of numerical data.  Modern spreadsheets also often contain databasing and word processing features.  These are not technically part of the spreadsheet itself, but merely extensions to it.

See also: VisiCalc, Lotus, worksheet, cell, table, word processor, database


SSCAD

Space Structures Computer Aided Design

See also: CAD, CAD/CAM


ST506, ST412

This is a standard hard disk interface developed by Seagate Technologies for use with the PC/XT and AT series computers and is now obsolete.  It was largely replaced by Western Digital's MFM standard which is also obsolete.

See also: IBM PC/XT, AT, hard disk, MFM


stack

Stacks are either memory locations within a processing chip (not necessarily just the CPU) or within RAM memory used to keep track of a sequence mathematical calculations or system operations such as hardware interface routines.  They are called stacks since they function like a stack of cards: the last item placed on the stack is the first to be processed (last-in-first-out).

Windows 3.1 automatically sets up DOS to install nine such areas of RAM memory, 256 bytes each, for such processes but they are rarely used by most newer software and advanced memory managers such as QEMM suggest eliminating them from the system to free more memory.

See also: random access memory (RAM), central processing unit (CPU), interface, routine, FIFO/LIFO, memory manager, QEMM


Stacker

Prior to Microsoft's MS-DOS 6.0 release, which included Doublespace disk compression software, Stacker was the most widely used disk compression software on the IBM-compatible.  Developed by STAC Electronics, Stacker has featured superior compression, speed and reliability to all competing products for several years.

Trivia

Industry-watchers widely credit STAC for Microsoft having to release several updates to MS-DOS 6.0.  Microsoft left serious, data-destroying bugs in the first version of Doublespace and in 1994 were successfully sued by STAC who claimed that Doublespace violated STAC's copyright.  Microsoft denies all such claims, of course.

See also: disk compression, data compression,


SDLP
Standard Device Level Protocol (SDLP)

A specification designed to allow cross-platform compatibility of SCSI devices.  This allows Macintosh and UNIX-type SCSI disk drives and CD-ROM drives, for example, to be used on IBM-compatibles and vice versa.  SDLP is designed to work between the SCSI controller and the computer hardware itself.  Not commonly used for home PCs.

See also: SCSI, ESDI


standard mode (Windows)

A mode of operation used by Windows versions 3.1 and previous, obsolete with Windows 95 which does not permit standard mode operation.  The term is rarely used today in context of Windows.

Obsolete terms since the release of Windows 95, which runs in 386 enhanced mode only.  Beginning with Windows 3.0 and continuing with 3.1/3.11, Windows was capable of running several programs simultaneously, sharing the workload between all running programs (Windows 3.1 only), and accessing hardware functions without the need to work through DOS providing the appropriate software was loaded when Windows was booted.  These new abilities comprise the enhanced part of Windows operation and usually the only mode people ever use.

Standard mode, an older method of working with Windows prior to Windows 95, limited Windows to just one active program at a time and did not permit the use of these special drivers.  Standard mode had an advantage over enhanced mode for some uses because its ability to focus on the work done by a single program allowed that program to function somewhat faster than the same program running in enhanced mode.  (Windows for Workgroups and Windows 95 do not permit standard mode operation.)

See also: 386 enhanced mode, real mode (Windows), multitasking, IBM PC/XT, 80286, boot, Windows for Workgroups, real mode (DOS)


static RAM (SRAM)

DRAM chips use a type of electronics called capacitance to store memory.  SRAM uses a type of circuit called a flip-flop or logic circuit, which make them many times faster than ordinary DRAM but also bulkier and more costly.  SRAM requires about four times the area of a DRAM chip to store the same amount of data.  SRAM is used for the 64K to 256K "external cache" on the motherboard and is also used as the sole type of RAM on some high-performance "dynamic cache architecture" motherboards.  Most modern DRAM has access times of 55ns to 70ns (nanoseconds); SRAM access time is usually 10ns to 20ns.

See also: dynamic random access memory (DRAM), chip, external cache, nano-


SNOBOL
String Oriented Symbolic Language (SNOBOL)

A computer programming language for manipulating strings of symbols.

See also: COBOL, FORTRAN


Structured Query Language (SQL)

A world standard database language originally proposed in the early 1970s by IBM mathematician E.F. Codd.  This extremely powerful database language is the new standard for cross-platform database compatibility, particularly on networks, and supports advanced features such as fully relational queries (searches) and advanced data management, security and recovery techniques.

See also: relational database, Query By Example, database


StudlyCaps

The indiscriminate BiCapitalization of TechnoSpeak.


Sun Microsystems

Manufacturer of high-powered microcomputers based in the US, their workstation computers have been the computers of choice for high-end graphical applications and commercial Internet service providers (the IBM-compatible has become more popular in recent years thanks to the growth of the Linux and BSD operating systems and the advent of parallel processing with the Pentium series chip).

See also: parallel processing Linux, Pentium


Super VGA (SVGA)

Consumer graphics display standard for the mid-1990s.  Allows color depth higher than the 256,000 color maximum provided by VGA and a screen resolution of 800x600 pixels (the VGA standard is 640x480).

See also: EGA, VGA, UVGA, resolution


supercomputer

Generic term referring to computers capable of feats beyond the capacity of computers in common use.  For example, a current 486DX home PC would have been a supercomputer a decade and a half ago.  Also a slang generic term for computers  developed by Cray Research, the best-known manufacturer of supercomputers for over a decade.

See also: Cray Research, minicomputer, superconductor


superconductor

A substance, not a hardware component.  Conductivity is the ability of a substance to allow electricity to pass through it without loss or resistance.  Rock makes a lousy conductor; many refined metals such as copper, aluminum and steel make good conductors.  Superconductive materials allow electricity to pass through with near-zero resistance, resulting in higher data transmission speeds, less energy requirement and lower maintenance.

Superconductors are the holy grail of hardware research at this writing, since the development of a usable, inexpensive superconductor that is superconductive at room temperature will literally skyrocket the potential speed of computers and allow telephone and other traditional data and electrical transmission media to carry more information with less interference.  Superconductive materials already exist; the difficulty with current superconductors is that they require extremely low temperatures to operate.  There are CPUs in use today which use superconductive materials, but they are usually packaged in a housing of supercooled liquid nitrogen.

See also: transistor, supercomputer, central processing unit (CPU), integrated circuit


swap file, permanent swap file, virtual memory
swap file, permanent swap file

Swap file refers to a section of a hard disk, floppy disk or other medium that a program uses to store information which the computer's physical memory is too limited to maintain.  Swap files are what permit Windows 3.1 and newer to run programs that need more memory than a computer might have.

The use of a swap file is a hindrance to performance as much as it is a way of enabling greater flexibility on an underpowered system, since the computer is using (usually) the hard disk for operations which could be done thousands of times faster if sufficient chip memory was available.

See also: virtual memory, memory, file, dynamic random access memory (DRAM), chip, virtual disk


syntax

In computing, it refers to the particular "grammatical" structure needed by a particular typed command, for example the number of spaces and locations of slashes and colons in DOS commands are part of DOS' syntax.

See also: disk operating system (DOS), command prompt


synthesis

Although the term is usually used to refer to the process of electronic sound generation used by a synthesizer, it can also refer to any process of building usable data from component parts.

There are three common types of sound synthesis in use in modern PCs and sound cards.  By far the most popular is Yamaha's FM (frequency modulation) technology, which takes a sine wave (a standard test-tone-like sound) and modifies it to produce a new sound.  Subtractive synthesis is used on older synthesizers and is based on the early Moog synthesizer architecture. Subtractive synthesis takes the same basic waveforms used in FM and subtracts elements of the sound until a new sound is created.  Hybrid synthesis usually refers to a type of synthesis that takes actual digital PCM samples of real sounds such as pianos, violins and drums and applies either subtractive or FM synthesis to once again create a new sound.  Most listeners prefer the richness of hybrid synthesis to either subtractive or FM synthesis, and most newer sound cards incorporate this technology.

See also: synthesizer, pulse code modulation


synthesizer

Generic term which usually refers to an electronic musical instrument (usually digital although early units used analog circuits) which creates sound from raw waveforms rather than generating sound from specific mechanical actions.

 See also: synthesis, base-level synthesizer, extended-level synthesizer, MIDI, pulse code modulation (PCM), sample


SYSRQ
system request (SYSRQ)

System Request: key which signals host computer during host session.  Found mostly on terminals; not used on IBM-compatibles.

See also: terminal, IBM-compatible


system clock

A calibrated quartz crystal used as the computer's internal timing device.  Depending on the shape of the crystal, it vibrates at a constant rate with the application of electricity providing a stable pulse that the system uses to time various functions.  The speed of a system clock is measured in megacycles or megaHertz, and this speed is usually used as the rating speed for the CPU on 386's and higher (e.g. a 486DX-33MHz uses a 33MHz. system clock)

See also: radio frequency interference (RFI), cycle


SYSTEM.DAT, USER.DAT

Two critical new system files used by Windows 95 to store a wide range of information.  Collectively they are known as the registry.  Most of the information contained here was formerly contained in the WIN.INI and SYSTEM.INI files used by Windows 3.11 and earlier.  These files are so important that they should be backed up daily by anyone who makes frequent changes to their system, as virtually every new Windows 95 program makes some kind of change to these files, and personalized system settings are also stored here.

See also: registry


system disk

System disk refers to a bootable disk that also contains the necessary files for starting the operating system.  A disk can be bootable without containing this information.

See also: kernel, boot disk, operating system


tab
tab, tabstop

Two common meanings in computing.  The first stems from typewriter technology.  Tabs were flanges of metal which could be set at various points along the carriage so that the typist could move to a specific location on a given line of the paper without having to repeatedly press the space bar.  The idea is so useful for creating cleanly indented text and smooth-looking tables that it is used by virtually all popular word processors and text editors.

PCs also have a special character to indicate that a tab has been used, and the size of this tab (usually four or eight spaces) is configurable from the program in which tabbed text is viewed or edited.

Tabstops refer to the hardware that stopped the carriage at the desired point; tabstops on a computer stop the cursor at the desired point.

Tab also refers to a small visual flange at the top, bottom or side of a window that corresponds with a menu choice.  Tabbed menus were not common on PCs until the release of Windows 95, which replaces many types of menus used in previous versions.  Windows 95 users can see a sample of a tabbed menu by clicking the Search button at the top of this window.

See also: carriage return, word processor, text editor, cursor, menu


table

A table refers to a specific arrangement of data used in spreadsheets, databases and report generating software.  They are used as a visually pleasing and easy-to-understand method of presenting data onscreen or on paper.

Tables are structured in two dimensions, with the divisions of the vertical axis referred to as columns and divisions of the horizontal axis referred to as rows.  Any data structured for display in this method is referred to as a table, so a spreadsheet could also be referred to as a table.

This text represents a table two columns wide by three rows deep.  This is the first row, first column.	This text represents a table two columns wide by three rows deep.  This is the first row, second column.
This text represents a table two columns wide by three rows deep.  This is the second row, first column.	This text represents a table two columns wide by three rows deep.  This is the second row, second column.
This text represents a table two columns wide by three rows deep.  This is the third row, first column.	This text represents a table two columns wide by three rows deep.  This is the third row, second column.
See also: database, x- and y-axis, spreadsheet,


Tagged Image File Format (TIFF)

Codeveloped by Aldus, Microsoft and major scanner manufacturers, TIFF was designed as a means of storing digitized scanned data, usually graphics, in a format that could be transferred across platforms.  It has become a popular format for everything from desktop publishing to photo retouching to fax transfer.  The TIFF format is known for effectively reproducing large, detailed images and also includes facilities for data compression to reduce the file size for retransmission over networks and phone lines.

See also: platform, data compression, desktop publishing, scanner, Graphics Interchange Format (GIF), JPEG, PNG


Tandy

Until the late 1970s, Tandy Corporation was known primarily as the parent company of Radio Shack, the electronics franchise giant.  Tandy was the brand name reserved for their line of craft tools.

That changed forever in the early 1980s when Tandy became major players in the personal computer sweepstakes.  Their first major entree was the ColorComputer, or CoCo as it was known, an inexpensive competitor to the Commodore VIC-20 and C-64 home computers based on the Motorola Z-80 microprocessor.  Tandy's place in PC history was assured though with the release of the Tandy 1000, a sort-of-IBM-compatible featuring low-cost color graphics which was wildly popular for several years and made the IBM-compatible a viable home entertainment alternative several years before EGA graphics became popular.  The Tandy 1000 is now obsolete to the point of boat-anchor material.

Today Tandy still sells computers through their Radio Shack affiliates, but their products are generally sublicensed name brand systems and components.

See also: proprietary, VIC-20, C-64, Motorola, EGA, boat anchor


tape backup unit

A peripheral device for archiving data in a tape format.  Tape backup units can either be built-in or external units which use tape cartridges a little smaller than an audio cassette to create backup copies usually of hard disk data.  These units were usually reserved for business use due to their high cost but around 1994 costs came down to the point where a large percentage of home computers now have tape backup.

These devices have capacities ranging from 20Mb (older style) to over 500Mb, and are the most cost-effective archive storage method in use today for the average computer owner.  They have one drawback: speed.  Copying and retrieving backup data on tape is a slow process.

See also: backup, peripheral device, archive, QIC,


task

Geekspeak for "chore".  Each program or process within a program is represented to the operating system as a task to be performed, hence "multitasking" and "task switching".  A single Windows application can have several tasks running at once; most DOS applications only have one.

To see which tasks are running at any given moment within Windows, press and hold the Ctrl key and tap Esc.  A program called Task Manager will pop up.  Unfortunately this will not give you a true picture of the tasks running within Windows, since many applications run certain tasks hidden from the operator.

In Windows 95, Task Manager is called with Ctrl+Alt+Delete, which is not a key combination to be used with Windows or DOS, since it may reboot the computer.

See also: application, time slice, multitasking, Ctrl+Alt+Delete,  multithreading boot


task switching

Often confused with multitasking.  Task switching is the ability of an operating system to allow more than one application in memory at the same time and permit the operator to switch between them.  It is not multitasking, although the line is a very thin one.  For example, Windows 3.0 allowed the user to have many programs in memory at once and switch between them at will, but it did not permit more than one program to perform operations.

Windows 3.1 is allegedly a multitasking operating system, but since it assigns processor time to one application at a time in tiny slices, technically it is still a task switching operating system; it only looks like true multitasking because the switching happens so rapidly.

See also: task, application, time slice, multitasking, multithreading


TECHMOD
Technology Modernization Program (TECHMOD)

A US government-sponsored CIM research and development funding program.

See also: CIM


technology without an important name (TWAIN)

TWAIN is an interface standard used primarily with scanners and digitizing tablets designed to allow software to "acquire" raw data from these devices and format it into a standard image type without leaving the program where the image is processed.  TWAIN functions with Windows and OS/2 and on Macintosh computers through the use of device drivers, and many popular graphics processing packages support this standard.

See also: scanner, digitizing tablet, image, device driver, OS/2, Macintosh


template

A basic design or layout into which specific data is meant to be fit.  Fill-out or clickable forms, macros that require user interaction, blank documents and shells are all considered to be types of templates.

See also: macro


temporary file;file:temporary (tempfile)
temporary file

Also referred to as tempfiles, these are files created by a program for its own use as part of its operation.  Such files may contain data about files being used by the operator.  They may also be temporary backups of files opened as works-in-progress.

Many Windows programs create temporary working files for different purposes.  These files are nearly always stored in the same common directory, usually labelled TEMP but often stored in C:\DOS or C:\WINDOWS where no TEMP directory has been created.  They are also easily identifiable as temporary files since they begin with a "~" or tilde character.  These files can nearly always be deleted as part of routine file management, since Windows will not allow any such files to be deleted if they are in use by a program running on the system.

See also: file, backup, file management


terminal

Refers either to a diskless workstation (a monitor, keyboard and perhaps a mouse and a minimal processor) connected to a network or a hardware pin or connector end.  Usually confused with terminal emulator; a terminal emulator is what most PCs use for connecting to dialup networks such as BBS' and Internet.

See also: Internet


terminate-stay resident (TSR)

A personal computer program designed to be run once which then remains in memory for the use of other programs; this permits its features to be accessed without the need for individual programs to duplicate the functions of this program.  TSR's are designed both to eliminate the need for extra code in other programs and to improve or augment the performance of existing programs.

See also: memory resident, upper memory area (UMA)


TeX, LaTeX

Extremely powerful macro-based text formatter written by Donald E. Knuth, very popular in the computer-science community (it is good enough to have displaced UNIX troff, the other favored formatter, even at many UNIX installations).  LaTeX is a variation of TeX which has grown at least as popular among UNIX hackers due to its greater ease of use and focus on formatting as opposed to programming.  LaTeX was developed at SRI International's Aritificial Intelligence Laboratory.

See also: macro, UNIX, format, desktop publishing, hacker


Texas Instruments
Texas Instruments (TI)

Known to most computer users as a calculator manufacturer, TI has been involved in microprocessor development and manufacturing in many computer-related areas since the birth of the PC.  Known simply as TI to industry watchers and fans, they were responsible for one of the most popular of the early PCs: the TI-99/4A.  This was a small, 4K computer on a par with the Commodore VIC-20, expandable to comparable capacity to the Apple ][ series, and well-supported with software by users and manufacturers.  It is still prized as a hobby and nostalgia machine.

Texas Instruments is probably best-known today to most users as manufacturers of CPU chips competitive with the Intel line.

See also: Texas Instruments Graphic Architecture (TIGA), microprocessor, VIC-20, Apple, central processing unit (CPU)


Texas Instruments Graphics Architecture (TIGA)
Texas Instruments Graphic Architecture (TIGA)

A relatively new and not yet common graphics specification developed by Texas Instruments. It is supposed to run independent of color depth or screen resolution so theoretically it should be compatible with all future graphics standards…provided they conform to the TIGA standard.  Working TIGA device drivers are available for Windows and Windows 95, so this appears to be a viable alternative to the standard resolution-dependent graphics architecture used by most IBM-compatible video hardware developers.  TIGA cards are generally premium-quality devices used in the graphic arts and video industries.

See also: Texas Instruments (TI), color depth, resolution


text editor

A program designed for the creation or modification of text-only (non-binary) datafiles.

See also: word processor, text processor, filter


text file, ASCII file

Generally speaking, a file containing readable text with only the standard typewriter characters and no special characters or formatting, although it can loosely refer to files which contain IBM graphical characters such as bars and line drawing symbols.  Such files are also referred to as ASCII files.

See also: file, ASCII, format, document, word processing


text mode

Also known as character mode, text mode refers to a mode of graphical operation used by DOS.  Text mode allows only the use of the IBM character set built into the fonts on the computer itself, and permits the use of color only as a means of coloring individual characters or their backgrounds.  (Text mode occasionally looks like a primitive graphics mode because the IBM character set includes many characters designed specifically for drawing graphical objects.  To make matters confusing, objects drawn with these characters are often referred to as text mode graphics.)  Text mode places virtually no strain on most graphics cards.

When an IBM-compatible computer is going through its boot sequence, it is in text mode, and virtually all utilities and programs included with DOS are text mode.  Windows and OS/2's GUI do all of their work in graphics mode.

See also: graphics mode, pixel, typeface, font, mode, boot, disk operating system (DOS), OS/2, graphical user interface (GUI)


text processor

A piece of software designed to process and format text information in a variety of ways.  Text processors work primarily as filters or formatters for existing documents.

See also: word processor, text editor


thin film transistor (TFT)

A type of display used on high-end laptop and notebook computers requiring optimum graphical capabilities.  Each pixel on the screen is an LCD segment which can be activated by between one and four transistors.  Single transistor models provide two-color black and white displays; four-transistor models provide color.  Expensive technology for most users, this is also known as active matrix.

See also: laptop/notebook, pixel, liquid crystal display, Plasma Display Matrix (PDM), transistor


third generation computer

Third generation computers are usually classified as those in common use from the mid-1960s through the mid-1970s.  Third generation computers were the first to use integrated circuits as primary components and floppy and hard disk storage.  Examples of third generation computers are the IBM/360 series.  There is some dispute about whether the earliest popular computers, such as the Commodore PET once common in schools, are actual fourth generation computers or merely advanced third generation computers.  There seems to be a general feeling that fourth generation computers really only began with large-scale integration of circuitry that allowed for thousands, not just handfuls, of transistors on a single chip.

See also: first generation computer, second generation computer, fourth generation computer, fifth generation computer, VLSI, chip, integrated circuit


three-state check box

A relatively new feature of the Windows operating system which allows a check box to have three possible options, or states, instead of just two.  There is usually an ON and an OFF, but there is also a third state used to indicate ON AND, ON NOT or ON BUT.  For example, three-state check box in a word processor might be used to show that a selection of the document is either boldfaced text, not boldfaced text, or partly boldfaced (ON BUT not completely on).

See also: check box, dialog box, boolean


thumbnail, contact sheet

Thumbnail is a term most often used in graphic design and desktop publishing, but becoming more common with day-to-day computing.  It is as it might seem, a "thumbnail sketch".  Thumbnails usually refer to miniaturized versions of graphic images created for reference purposes, usually as a catalog of available images.  However the term can also refer to condensed data of any sort, from a stripped-down database to a spreadsheet showing only totals of other spreadsheets.  Another example of a thumbnail is the miniaturized view of the desktop displayed by Windows as a reference point when the user changes color schemes.

Contact sheets are graphic images composed of a group of thumbnails.  The term stems from photography, where a contact sheet is a developed image of film negatives which are "thumbnail pictures" the size of the negatives themselves.

See also: desktop publishing, database, spreadsheet, image


thunk

"A piece of coding which provides an address", according to P. Z. Ingerman, who invented thunks in 1961 as a way of binding actual parameters to their formal definitions in Algol-60 procedure calls.  If a procedure is called with an expression in the place of a formal parameter, the compiler generates a thunk which computes the expression and leaves the address of the result in some standard location.

Later generalized into: an expression, frozen together with its environment, for later evaluation if and when needed (similar to what in techspeak is called a "closure").  The process of unfreezing these thunks is called "forcing".

A stubroutine, in an overlay programming environment, that loads and jumps to the correct overlay.  Compare trampoline.

People and activities scheduled in a thunklike manner.  "It occurred to me the other day that I am rather accurately modeled by a thunk --- I frequently need to be forced to completion." --- paraphrased from a plan file.  [Source: The Jargon File 3.0.0]  Not commonly used by PC owners prior to Windows 95.

See also: ALGOL, parameter, call, overlay, routine, compiler


tile

Refers to a process Windows uses for laying out either graphics or other windows.  When used to refer to windows, tiling is the effect of having several windows open at once, each occupying a specific section of the screen, so that if four windows were open at once, each "tile" would occupy one-quarter of the screen.  Tiling is usually used to arrange windows within a specific program, rather than arranging all windows in a computing session.

Tiling can also refer to an effect used by Windows and graphics programs for laying out graphics.  When a single small graphic is repeated in rows, squares or rectangles until it fills the screen with copies of itself, it is said to be tiled.

See also: cascade, background, wallpaper


time bomb

Three common meanings: can refer to a timed software mechanism designed to cause a problem in a system at a later date, often "planted" by a fired or laid off employee, or to a device used in free trial software to disable the functionality of the software after a predetermined period of use (usually 30 days), or to a virus that lies dormant on a computer until a specific date or time (Michelangelo and virtually all of the Christmas virii are examples of time bomb virii).

See also: virus, trojan horse, shareware


time slice

Time slicing is the most primitive form of multitasking and the method of multitasking used by the DesqView DOS multitasking system and Windows 3.1.  It divides up processor usage into brief segments or slices of time and assigns these slices to the programs needing the processor in a manner determined by the operating system.

Time slicing is far easier to program and control than true multithreading because it does not truly divide up processor usage, and some people claim that since the CPU is still handling only one task at a time, time slice multitasking is actually just a sophisticated form of task switching and not multitasking at all.

See also: multitasking, central processing unit (CPU), operating system, multithreading, task switching


TOF

Top of file


toggle

Literally, to switch.  Although Windows asks you to believe that this term relates to changing the state of an object with two states (on/off), it can refer to switching between any number of programs, processes or activities.  For example, every day at noon most of the population toggles between work mode and lunch mode.

The term stems from the toggle effect of all switches with fixed positions.  Light switches are examples of toggle switches.  Auto ignitions are "sort of" toggle switches, since the key toggles the engine on and off.  The actual ignition uses a momentary switch, because the key is turned to the ignition position for only a moment and cannot stay there on its own.

See also: transistor, boolean


toner

Rather than using liquid or oil-based inks the way most printers do, laser printers and electrostatic photocopiers use a dry powdered substance known as toner to create images on paper.  An explanation of the process is given at the topic referenced below.

See also: laser printer


toolbar
toolbar, tooltips

A concept developed for Microsoft Windows which adds an iconic menu to the top menu bar of Windows programs.  This menu consists of a collection of small icon "buttons" designed to access the program's functions without searching through menus nested within menus.

Tooltips refers to the text messages displayed beside toolbar icons when the mouse cursor is held over a toolbar icon for a second or longer.  These text messages offer an explanation of the iconic button's function, an essential feature considering the difficulty most users have with associating a small icon with a specific menu function.

Tooltips are not universally used within windows, but most programs offering toolbars support their use.

Toolbar (capitalized) is also used to refer to a freeware menuing program for windows developed by Juan Aguirrebiria and very popular with Windows power users.

See also: menu bar, icon, menu


trace

Printed circuit boards are meant to eliminate wiring by having the wiring embedded directly into the circuit board itself.  The idea is to draw paths between the necessary components so that all components can fit on a single circuit board and the fewest connecting wires possible are required.  The printing process burns away copper from the surface of the circuit board leaving a pattern of flat copper paths between the necessary components.  These paths are referred to as traces or circuit traces.

See also: printed circuit board


track

A track on a magnetic storage device is an area where data is stored.  Tracks are found on magnetic tape (including audio cassettes), floppy and hard disks.  If they were visible, they would look like rings on a tree trunk, and there are 80 such rings, or tracks, on the average 3-1/2" floppy disk.  On double-sided disks, disks where both sides of the media can be read and written, a track refers to the same circular area of disk space on both sides of the disk.  In hard disks with multiple platters, tracks refer to the circular areas on all of the platters in the stack.

Track also refers to the process of tracing a specific pattern, particularly usage of a system, program or process within a program, as in tracking changes to a document.

See also: sector, cluster, hard disk, platter


trackball

This device is an alternative input device to the mouse which functions essentially in the same way.  Trackballs are used where desk space is not sufficient for the use of a mouse, especially with laptops and notebooks, where the user may have difficulty moving the wrists due to injury or other constraints (smaller trackballs can be held in the hand and do not need a flat surface), or where there is an ergonomic need for an alternative input device, such as in the case of repetitive strain injury.

See also: laptop, repetitive strain injury (RSI)


tractor feed

A method of feeding paper into a printer which uses special paper with perforated, punched edges.  The stereotypical method of printing on a PC.  The punches on the edges of the paper are designed to line up with nubbed rollers on the printer and allow the printer to automatically feed and print as many sheets as the "web" of paper can supply (usually 500 sheets in a single web but can be as high as several thousand sheets).  This is the more wasteful of the two printing methods, as tractor-feed printing requires trimming of the perforated edges and is not usually reprinted on the unprinted side, whereas sheet-fed pages can easily be reused.

See also: sheet feeder


transistor

Although it is generally agreed that "transistor" is a bastardized term that has no solid etymological basis, loosely speaking it can be conveniently viewed as a "transcendental resistor".  A resistor is designed to block the flow of electricity, and semiconductive materials do just that when at rest.  However, with the application of a small amount of heat, light or other form of energy, this material "transcends" its resistive state and becomes conductive, allowing energy to pass through it.  This ability to act like a switch, on or off depending on whether energy is being applied to it, forms the basis for all modern electronics and makes reasonably-priced computers possible.

See also: semiconductor, integrate, integrated circuit


trap

A program interrupt, usually an interrupt caused by some exceptional situation in the user program.  In most cases, the OS performs some action, then returns control to the program.  Also to cause a trap.  "These instructions trap to the monitor." Also used transitively to indicate the cause of the trap.  "The monitor traps all input/output instructions." [Source: The Jargon File 3.0.0]

See also: interrupt, operating system, errorlevel


tree

Refers to the way directory structures are viewed in Windows directory navigation programs such as Explorer or File Manager.  So named because the directory structure, when fully expanded, looks like a family tree diagram turned on its side.

See also: branch, collapse, expand, directory structure, root


trojan horse

A computer program which carries within itself a means to allow the creator of the program access to the system using it.

See also: virus


TrueType fonts
TrueType

TrueType is the form of scalable font used most often on IBM-compatible computers, and also on Macintosh and more recently UNIX systems, and probably the most popular type of scalable font in the world.  TrueType fonts are scalable, meaning they can be sized to any height, and they print exactly as they appear on the screen.  There are literally tens of thousands of TrueType fonts available.

See also: font, scalable font, typeface, Adobe Type Manager, softfont, bitmap, jaggies


Turing machine

Often spoken of in hushed tones among hackers and enthusiasts alike,  this is a theoretical device first put forth as a concept in the mid-1930s by Alan Turing.  It consists of a model reading a set of instructions and acting based on the next instruction in the chain, and comprises the basic theoretical framework for all modern computers.  Some claim the Turing machine proves that artificial intelligence is not possible, but it is believed that this does not take into account the fact that neural networks function within this theoretical framework.

See also: artificial intelligence (AI), neural networks


turnkey

Not specifically a computing term, but used often in relation to commercial computer systems.  Turnkey refers to a product package that is complete and ready to use, including hardware and software.  Literally, "turn the key and it goes."  Turnkey systems are usually sold by retailers who deal with the commercial market, and the provision of complete, ready-to-use turnkey systems is usually mentioned as a distinguishing feature of VARs.

See also: value-added reseller (VAR)


typeface

Refers to a family of fonts.  For example, Arial, Times, Courier and Lucida are typeface families, since they can comprise several fonts.  Windows comes with all four typefaces in several fonts, so that each can be used as a regular, boldface (dark) font, italic (slanted) or bold italic rather than just as a single type of font.  Some of the more common typefaces, such as Helvetica, Futura, Times and Palatino, can have literally dozens of fonts to represent different weights, slants, and effects such as hollow or three-dimensional lettering.

See also: font, TrueType, Adobe Type Manager


ultra-large scale integration (ULSI)

A method of electronic component manufacture that permits more than a million components (resistors, transistors, etc.) within a single integrated circuit.  Modern CPU chips are examples of ULSI circuits.

See also: large-scale integration (LSI),  very large scale integration (VLSI), integrated circuit, central processing unit (CPU), chip


Ultra-VGA
Ultra-VGA (UVGA)

A high-end video graphics standard used primarily by professionals for pixel and color resolutions higher than the consumer Super VGA standard 800x600x256.

See also: Super VGA, VGA, PGA, XGA, Texas Instruments Graphic Architecture (TIGA), resolution, pixel


undocumented feature

Seldom of use to casual users, undocumented features are aspects of a program which are not normally available and not covered in manuals, online help or other documentation.  Virtually every large program, particularly operating system software such as Windows 3.1/3.11 and Windows 95, will have many undocumented features.

These features are sometimes bug-like anomalies, or ways of manipulating the program or its data which the programmers never discovered, but more often they are leftovers from the programming and testing stages, when the programmers created certain functions in order to test the integrity or versatility of the software and never removed these features from the finished product.  Finding a useful undocumented feature in operating system software and being the first to put it to use in a practical fashion is one of the greatest thrills in programming.

We'd show you an example of an undocumented feature in this help tool, but if we did, it wouldn't be undocumented any more.

See also: Easter egg bug, beta test


Unicode

A relatively new encoding scheme that provides a facility for creating a usable computer alphabet for every character in common use in every common language on earth.  Unlike ASCII, which uses eight bits and allows only 128 possible characters, Unicode is a 16-bit alphabetical byte, which means there can be 65,536 characters assigned to individual patterns of 16 bits.  Unicode is, in effect, the universal computer language although it is still not very common.  It is believed that Unicode will be available on all computers by the end of the century, and software for creating and translating Unicode already exists for virtually all platforms.

See also: bit, byte, ASCII


uninterruptible power supply (UPS)

A UPS is a battery-powered device designed primarily to provide emergency power to a computer system and used primarily in areas where outages are frequent.  The UPS functions as the computer's actual power supply, since all power to the computer routes through the battery.  UPS' are generally used for allowing users sufficient time to save all work and properly shut down the computer during a power outage, and most include power conditioning features.

See also: dirty power, power conditioner


UNIX

Operating system created at Bell Laboratories, UNIX was based on the C language and engineered for portability across hardware platforms.  Considered by hackers to be the most flexible and powerful operating system in existence today.

There are two major types of UNIX: System V, developed by AT&T; and BSD 4.x, created at the University of California at Berkeley.  The former is the basis for most high-end corporate and industrial UNIX systems; the latter is the popular choice with smaller businesses and institutions. The two types are not as compatible as their sub-types.

Among the most popular sub-types of BSD 4.x are Linux and FreeBSD, which are extensively used in small-scale Internet provision.  UNIX is rarely used on home computers except by hackers or hackers-at-heart, although its use is growing as PC power increases and Linux/FreeBSD software databases grow.

See also: Linux, operating system, clone, hacker


upgrade, update

These two terms are widely misused by consumers.  Upgrade generally refers to a major improvement or major change (as many users discover, upgrades are not always improvements) in a piece of hardware or software.  Update usually refers to an improvement designed to fix or patch a bug or to accommodate changes in software or hardware which the particular product is frequently used with.  For example, Windows 95 is an upgrade over Windows 3.1, but Windows 95 is only an update to the Windows 95 beta test version which had been available for over a year before Win95's release.

See also: patch, bug, version, beta test


upper memory area (UMA), upper memory block (UMB)

The upper memory area refers to all memory in the range between 640K (the upper limit of conventional or DOS memory), and 1Mb on computers with 80386 and newer CPUs.  This area is supposed to be reserved for the hardware, and for mapping ROMs into RAM for better system performance, but in practice there is usually a substantial amount of unused memory once the hardware has claimed its real estate.

Upper memory blocks are 4K blocks of space in the UMA which are used to store memory-resident programs, device drivers and other code that is needed by the system and can be moved to locations other than the first 640K of memory.  The advantage of using these UMBs is that the more drivers and memory-resident programs that can be loaded into UMBs, the more memory is available for use by DOS programs.

See also: high memory area, conventional memory, central processing unit (CPU), read-only memory (ROM), memory resident, device driver


user resources (USER.EXE)

USER.EXE is the Windows program launched when Windows is started which manages the user module.  The user module is responsible for creating and manipulating windows, buttons and dialog boxes.  USER.EXE manages user resources, one of three critical 64K "heaps" used by Windows for managing its core functions.  Users mainly know this as part of Windows 3.1/3.11 which crashes with frightening regularity, due mainly to programs which allocate either too much of this critical resource or refuse to release the resources when the program exits.

See also: GDI, heap, kernel, dialog box


user supported software

Although this term is often used to refer to all shareware which requests a fee for use of the program, user supported software is actually a form of shareware in which the author requests payment only if the user feels the software is worth supporting with payment.  In effect, it is the current utopian pinnacle of software distribution, since it recognizes the need for the author to earn money from their work but still allows the user to make use of the software without payment if they so choose.

See also: shareware, freeware, Association of Shareware Professionals (ASP), license


utility

Usually used to distinguish a type of program from an application.  Utilities are usually said to perform functions related to the maintenance of hardware and data rather than direct data manipulation.  Utility can also be used to refer to any program which alters data in files but does not necessarily create new, usable data, or which is designed for the purpose of maintenance and/or tuning of the computer.  A fuzzy term with no precise meaning.

See also: application, program


value-added reseller (VAR)

Refers to a company in the computer industry which sells software or hardware manufactured by another firm.  The "value-added" part usually refers to the fact that VARs usually offer more than just hardware and/or software (e.g. training, on-site setup and support) that the manufacturer cannot or will not offer directly to its clientele.

See also: OEM


vanilla

Depending on the context, can mean plain, ordinary, featureless or unaltered from original configuration.  Usually refers to software, as in "I couldn't stand the inflexibility of vanilla Doom, but I'm probably going to lose my job if I don't stop playing Doom II.")

See also: Doom


vaporware

Software or hardware that does not exist and never will, or software announced so far in advance of actual release that users become hostile to the publisher.  Chicago, which later became known as Windows 95, is the most famous example of vaporware, released nearly a year and a half after its advertised publication date.

See also: FUD


VCR

Video Cassette Recorder


VDI

Virtual Device Interface


VDM

Virtual Device Metafile


vector graphics

Also referred to as object-oriented graphics, this is the method of design used by most CAD and raytracing software, and also the method used in creating TrueType and other scalable fonts that appear just as smooth at any size.

The name derives from the fact that these graphics are drawn using vectors (straight or curved lines), which are represented as extending within a percentage of a given area; rather than painted to specific pixels on the screen.  Using a percentage of a given area for a circle or curve allows vector graphics to resize themselves without becoming jaggy or excessively distorted.

Simple vector graphics such as line drawings usually require less memory and disk space than comparable bitmapped graphics, but the more complex the graphic image, the more lines and numbers have to be recorded in the file and hence the more memory it takes.

See also: bitmap, computer-assisted design (CAD), raytrace, Truetype, font, pixel, bezier curve, jaggies


vendor-independent mail (VIM)

A standard for developed by Lotus which allows programs using it to send email regardless of the application type.  With Windows and OS/2, VIM calls a DLL which provides an interface to email capabilities on the computer using it.

See also: DLL, OS/2


version, revision

Version and revision are used interchangeably to describe the state of a given piece of technology, and version numbers are the computer industry equivalent of model years for cars.  Version and revision are also used as slang terms for the act of applying version and revision numbers to products (e.g. "When Microsoft versioned Windows in 1992 to 3.1, many people felt they should have versioned it 4.0 because of its improvements over 3.0.").  Version numbers are not always sequential.  For example, Microsoft released Word for Windows 2.0 and then released their next version as 6.0.  There was no version 3,4 or 5 on the Windows platform.

There are few standards used for versioning, but revisioning is usually done using dates, or revision dates.  For example, a program named SuperStuff might be versioned Superstuff Revision 0495 to indicate that it was last updated April of 1995.  Some programs are revision dated down to the hour.

See also: update, platform


VLSI
very large scale integrated circuit (VLSI)

Refers to a manufacturing process that allows for thousands of components (transistors, resistors, etc.) to be housed in a single package.  Still in use for chip manufacture; largely replaced in high technology by ULSI.

VLSI was also the name used by a firm manufacturing chipsets for PC motherboards.

See also: large-scale integration (LSI), ultra-large scale integration (ULSI), Ic, transistor, semiconductor, superconductor, chipset, motherboard


VESA Local Bus
VESA Local Bus (VLB, VL Bus)

A system of hardware architecture originally intended for video cards which has since been applied to other type of peripheral devices as well.  Used mainly on 80486-equipped motherboards, VLB offers performance increases over ISA (the 16-bit standard) and EISA (the previous "clone" standard for 32-bit CPUs) by allowing data related to the specific device to move directly from the CPU to the card itself, bypassing internal routing circuitry on the motherboard which is used by other architectures as a form of "traffic control".

VLB is used primarily by i/o cards (peripheral cards which handle mouse, joystick and disk drive data) and video adapter cards, and requires that the motherboard be equipped to handle VLB-type cards and data transfer.  Most earlier Pentium motherboards did not permit VLB alongside the usual PCI standard.

See also: VESA, ISA, EISA, PCI, clone, 80486, motherboard, peripheral device


vi

A UNIX acronym for visual interface, vi is the most widely-used full-screen text editor on the UNIX platform.  (Text editors can either be full-screen, displaying both text as it is written and text which has already been written; or line editors which create text documents a line at a time and display only the line in progess.)  Created by Bill Joy for BSD UNIX.  Not at all novice-friendly and far less sophisticated than EMACS.

See also: UNIX, text editor, platform, EMACS


VIC-20
VIC-20 (Commodore)

In the mid- to late-1970s, this was considered the premier low-cost home computer system, in a technological class with Atari's popular 2600 series home entertainment system.  It predated the Commodore C-64 and gave hundreds of thousands their first peek at affordable home computing.

The Commodore VIC-20 used a whopping 4K of memory, the same as the ground-breaking Atari 2600 system; came with program cartridges including primitive games and a BASIC language, plugged directly into the cable input of a TV set, and offered the possibility of adding a cassette data storage drive.  Actual floppy drives appeared later with the introduction of the C-64.  VIC-20s are often seen at garage sales in the mid-1990s at prices ranging from a dollar to ten dollars for a complete system excluding TV monitor.

See also: C-64, Atari, BASIC, memory


VDT
video display terminal (VDT)

Usually refers to the combination of monitor and keyboard comprising a terminal; also synonymous with CRT display or monitor.

See also: CRT, terminal


Video Electronics Standards Association (VESA)

Organization responsible for approving standards for video displays on personal computers.  Among other things, the VESA standards govern data i/o and video adapter technology on IBM-compatibles.

See also: VLB, PCI, adapter


VGA
Video Graphics Array (VGA)

The successor to EGA and the standard from the late 1980s to about 1994 for personal computer graphics.  Originally introduced as the IBM color graphics standard used on Personal System/2 (PS/2) series of home computer models, the standard has undergone several updates and enhancements.

See also: CGA, EGA, SVGA, greyscale, resolution


video RAM (VRAM)

VRAM chips are fast DRAM chips, specially engineered to allow for the faster data transfer needed by video displays and used mainly on high-performance models of popularly available video cards due to the higher cost of this technology.

See also: memory, dynamic random access memory (DRAM), static RAM (SRAM), peripheral card


virtual

Simulated.  Can refer to the use of disk space as RAM memory and any other situation where software or hardware is used to emulate software or hardware which does not exist on the machine in question.

See also: virtual disk, virtual memory, virtual reality, virtual machine, random access memory (RAM), emulation


VAX
Virtual Address Extension (VAX)

The most successful minicomputer design in industry history, possibly excepting its immediate ancestor, the PDP-11.  Between its release in 1978 and its eclipse by killer micros after about 1986, the VAX was probably the hacker's favorite machine of them all.  [Source: The Jargon File 3.0.0] Manufactured by DEC.

See also: Digital Equipment Corp. (DEC), hacker, PDP-10/11/20, VMS, minicomputer


virtual disk, RAMdisk

Virtual disks are areas of RAM memory which have been set aside as areas for temporary storage of data.  It functions exactly like an additional disk on the system but runs much more quickly than an actual disk.  These are also commonly known as RAMdisks, and the contents of these temporary disks disappears whenever the computer is turned off.  Virtual disks are not commonly used with modern PCs due to the ability of most computers to create swap files for use as virtual memory, but they were fixtures on most computers, from Atari STs to Macs and PCs, which did not have hard disks.

See also: random access memory (RAM), swap file, Atari, Macintosh


virtual machine

A virtual machine is, quite literally, a computer-within-a-computer.  Virtual machines are areas of memory set aside in multitasking and task switching operating systems which contain complete copies of the operating system and enough room for a given program to operate.  For example, Windows 3.1 and higher can have multiple DOS programs operating in the system at the same time.  Each of these programs gets its own area of memory and its own copy of DOS, and access to a full set of the basic 8086 machine instructions needed for basic DOS operation.  Windows 95 runs newer 32-bit Windows programs using the same system, a complete virtual Windows machine for each 32-bit program running on the system.

See also: multitasking, task switching, operating system, 80x86, bus, disk operating system (DOS)


virtual memoryachine
virtual memory

Virtual memory is the term for the use of a disk-based file as a substitute for physical memory when there is not enough chip memory on the system.  It is not virtual memory but real memory, since the hard disk is used the same way as memory chips are, but because of the difference in speed between swap file memory and actual machine memory, the data on the hard disk is referred to as virtual memory.  The file used for virtual memory is known as a swap file.

Windows 3.1 and Windows 95 use virtual memory dynamically, varying the swap file size depending on the current needs of the system unless they are specifically told to use a certain amount of disk space for virtual memory.  Allocating a fixed amount of space, usually double the amount of actual DRAM memory for Windows 3.1 and triple or quadruple the DRAM memory with Windows 95, tends to improve performance.  This fixing of disk space for use as virtual memory is called creating a permanent swap file.

See also: swap file, memory, file, dynamic random access memory (DRAM), chip, virtual disk


VR
virtual reality (VR)

A computer-simulated environment that deliberately attempts to mimic reality, usually using three-dimensional imaging and often sound and requiring interaction on the part of the observer.

See also: interactive, role-playing game (RPG), virtual


VSAM
virtual storage access method (VSAM)

A file structure allowing "keyed" search retrievals from databases, usually used on larger corporate systems.  ISAM is considerably more popular at this time.

See also: indexed sequential access method (ISAM), Structured Query Language (SQL), ORACLE, database


virus

A program which replicates itself on computer systems by incorporating itself into other programs which are shared among computer systems. See also: program, hacker, trojan horse, high-risk environment


VisiCalc

The first widely-used spreadsheet program, available for UNIX, Apple ][, CP/M and many other platforms of its day.  Obsolete.  See also: spreadsheet, Lotus, Apple, CP/M, UNIX


Visual Basic

Microsoft's object-oriented programming language and interface for Windows, Windows NT and Windows 95, said by many to be the language that brought high-powered programming capabilities to the average user.  The language used for literally tens of thousands of free, shareware and commercial programs for Microsoft Windows.

See also: BASIC, runtime library, Windows NT, interface


VMS

DEC's proprietary operating system for its VAX minicomputer.

See also: Digital Equipment Corp. (DEC), proprietary, operating system, VAX


volatile memory

Any memory whose contents disappear when the power is turned off is termed volatile memory.  Video RAM (VRAM), static cache RAM (SRAM) and dynamic RAM (DRAM) are all forms of volatile memory.

See also: video RAM, static RAM (SRAM), dynamic random access memory (DRAM), memory, cache


volume

In theory, volume should be fairly obvious: one book in the encyclopedia is a volume; one disk or drive on the system should also be a volume.  In practice it gets a little muddy.  Strictly speaking, volume should only be used to refer to a logical drive, meaning an actual disk drive or partition on the system identified with a drive letter.

In practice, though, people use volume to refer to a physical drive (an actual disk) or a logical drive (a section of a disk that behaves on the system like an actual disk), or even part of a logical drive.  For example, the large compressed files used by disk compression programs such as Stacker and DoubleSpace/DriveSpace are referred to as volumes.

See also: physical and logical drive, label, disk compression, Stacker


Von Neuman architecture

The basic architectural design scheme underlying most modern computers.  The name stems from John Von Neumann (1903-1957), a mathematician who first suggested the prototype model for the modern computer.  This model consists of a central processing unit to handle arithmetical functions, memory connected to this processor, the processing of instructions in sequence (one after the other), input devices to control how the data is processed, and output devices to display the results of the processing.

This particular architecture is nearing the end of its useful life, because there are severe limitations placed on the ability of processors and memory to communicate, limitations which have contributed to the paradox of software becoming complex at a rate the hardware can't handle.  This particular limitation is known as the Von Neumann bottleneck.

See also: memory, software


wait state

A pause in a computer's operation where it must wait a cycle of operation before completing a transaction between the CPU and the memory chips.  Wait states are designed to allow CPUs to synchronize with memory chips which are not fast enough to keep up with the processor.  Wait states are a performance inhibitor, but necessary with high-speed CPUs matched to slow RAM.  The ideal situation is to have zero wait states, or no waiting by either memory or processor for memory access functions.  The memory chips should be able to feed data to the CPU as quickly as it can be processed.

See also: central processing unit (CPU), memory, chip, cycle


wallpaper

In hacker slang: any useless data or printouts.  In Windows: graphics files used as visual backdrops to the desktop.

See also: background, desktop


warm boot

To restart an operating system without physically shutting off power to the computer.  The components are still "warm", or receiving electricity, while the computer is restarted.  Usually faster than cold booting and often a method of recovering data since a warm boot does not erase the contents of certain types of memory.  Warm boots are always reboots.

See also: cold boot, boot


wetware

From the novels of Rudy Rucker: the human nervous system, as opposed to computer hardware or software.  Can also refer to computer operators.  More recently the term has also come to mean theoretical software and hardware interfaces that can send and receive input directly to or from the human nervous system.

See also: software, neural network, artificial intelligence (AI)


WG

Working Group, a group or committee organized for the purpose of approaching a specific problem; or workgroup, a collection of individuals or computers, usually networked, oriented toward a like task.

See also: Windows for Workgroups, network, Internet


Whetstones

Software used by most popular PC benchmarking programs to measure operational speed in a wide range of areas as a single performance unit called a Whetstone.  It measures arithmetic functions performed by the CPU and gauges hardware performance only.

See also: central processing unit (CPU), MIPS, MFLOPS, Dhrystones, benchmark


wildcard

A wildcard is a character used to represent other characters, similar to the way wildcards function in card games.  They are used mainly for file operations such as finding, copying, moving, filtering and backup.

The common wildcard characters for DOS and Windows are the question mark (?) and the asterisk (*).  The question mark functions as a substitute for any single character, while the asterisk can substitute for whole groups of characters.

DOS wildcard syntax is very specific.  For example, MYTAX9?.WKS would find all spreadsheet files of "my taxes" for all years beginning with 9, and MYTAX?5.WKS would find 1985 and, if it exists 1975 tax return worksheets too.  The asterisk substitutes for groups of characters, so if MY were someone's initials, ??TAX95.WKS would find all tax worksheets beginning with two initials, but *TAX95.WKS would not.  The asterisk can only be used as the last character before the period or the last character of the filename (e.g. MYTA*.WKS or MYTAX95.*)

 See also: file, software, syntax, naming convention, eight-dot-three, filter, dialog box


Winchester drive

Originally, Winchester drives referred to removable hard disks, but the term later came to mean any hard disk, fixed or removable, and is now virtually obsolete.  The term stemmed from the Winchester 30-30 rifle, as the first such systems used twin 30-megabyte disks.

See also: fixed disk, hard disk


Windows NT

As of this writing at version level 3.51, Windows NT is Microsoft's top-of-the-line Windows product, a true 32-bit multitasking operating system designed mainly for high performance network-based computing.  The NT stands for New Technology, and Windows NT offered most of the new features now available in Windows 95 such as full 32-bit operation, long filenames, registry management of most desktop options and true multithreaded operation, a full two years before Win95's release.

See also: version, multitasking, long filenames, registry, multithreading, Windows for Workgroups


Windows for Workgroups

Windows 3.11 is not the same as Windows for Workgroups.  WFWG, as it is often referred to, is a Windows package released in 1993 designed to add full networking capability to the base operating functions of Windows 3.1.  It includes networking software, email, fax, scheduling and other applications as bundled extras, as well as a few performance enhancements over Windows 3.1, and was sold as a consumer product as well as an actual networking operating system, but it was not a new release of the Windows operating system, since the core non-networking functions of Workgroups were the same as Windows 3.1.

Windows 3.11 was, in Microsoft's words, a "driver refresh", an update with no significant new features.  Released in 1993 but not actively marketed until late 1994 when 3.1 stocks had sold out, it included a few minor fixes and enhancements over Windows 3.1 but was not an actual upgrade.

See also: Windows NT, upgrade, bundle, network, version


WIP

Work in progress


wire frame

A type of modelling for creating computer-generated images; akin to working with papier mache.  The basic outline of the three-dimensional object is built using a collection of lines that resemble a wire framework and the details of the object are built around it.

See also: line art, raytrace, AutoCAD, CAD


wizard

A term apparently concocted by Microsoft to describe a type of walk-through help developed initially for their Microsoft Office suite of applications (Word, Excel and PowerPoint) and now implemented on a wide range of Windows 3.1 and Window 95 applications.  Wizards are designed to assist novice users through step-by-step processes, ranging in complexity from the installation of new software to the creation of complete desktop publishing documents, without requiring the use of the manual or any prior knowledge of the program.

This topic is also the first screen of a demonstration wizard created to show how the process works.  Click the Next Topic button to continue with this short demo.

See also: application, Microsoff, install, desktop publishing


wizard mode

Refers to special access, usually protected by a password, that allows a given user access to the core configuration functions of a program, usually a game, for purposes of experimentation.  Stems from an early computerized dungeons'n'dragons game named rogue in which the system administrator or programmer was allowed a "cheat mode" in which to hack aspects of the game.

See also: role-playing game (RPG), Hack


WO

Write Only


WPI
Worcester Polytechnic Institute (WPI)

Site of a very active community of PDP-10 hackers during the 1970s.

See also: PDP-10, hacker


word

Rather than use the term byte for a unit of storage on computers that allow the transfer of data more than 8 bits at a time, the term word is used, although word also refers to an 8-bit unit of storage on an 8-bit computer.  Modern 386 and 486 chips transfer data 32 bits at a time, so each memory location where this block of data is stored is referred to as a word.  Pentium and Pentium Pro computers use a 64-bit word.

See also: bit, byte, bus, Pentium


WordPerfect

Refers either to WordPerfect Corporation, an American software giant most notable for their WordPerfect software.  Wordperfect is also novice slang for any word processing program (e.g. "What kind of wordperfect do you use?  I prefer Word for Windows myself.")

See also: Novell, desktop publishing, word processing


word processing

The act of formatting a text document which may also contain graphics for purposes of viewing or printing, usually by others.  The line between word processing and desktop publishing has become blurred in recent years; the sophistication of modern word processors now gives them facilities once reserved for desktop publishing software and vice versa.

See also: text processor, desktop publishing, text file, text editor, WordPerfect


word processor

A piece of software designed to process text into documents for printing or transmission.  Word processors are used for both the development of new documents and the alteration and reformatting of existing documents.

See also: text processor, text editor, WordPerfect


word wrap

Refers to the ability of most modern text editors and word processors to take lines longer than can be displayed on the screen or in a window and break the line into two or more lines so that all text in a document can be viewed onscreen.  Word wrap can either be saved as a parameter of the program used to view the document or used as a temporary option for viewing files depending on the ability of the program to use this feature.

See also: text editor, word processing, document, parameter


working directory

An important Windows term relating to the system environment in which a program is operating.  Although a program might be opened from its own directory, which contains all the files it needs to run, working directories can be set so that when the operator opens or saves a file or looks for data within a file, the directory set as working directory is the first place the program looks or shows the operator in a dialog box.

Not all Windows programs allow working directories to be changed without affecting the performance of the software, but the ones that do offer users the opportunity to add a significant amount of speed and ease of use to the program's operation.  For example, setting the working directory of a word processor to the directory containing the most frequently accessed documents can save a stenographer ten minutes a day of changing directories.

See also: program, directory, dialog box, word processor, document


worksheet

Generally used when referring to spreadsheets.  A worksheet is a single data file from a spreadsheet program.  Newer spreadsheets allow integrated "3D" operations in which changes made to, for example, the general ledger show up on an employee's individual worksheet.

See also: integrate, spreadsheet, cell


WORM
write once, read many (WORM)

An optical disk formatting technique using spiral pattern of pits; designed to allow accumulations of large amounts of permanent data storage in a small space.  WORM drives are used in situations where high volume long-term storage is needed with the ability to add to an ongoing archive on a regular basis.  Graphic design houses and software development firms are frequently users of WORM drives.

See also: rewriteable optical storage, magneto-optical storage, archive


write precompensation (WPC/WPCOM)

This is a feature of hard disks used to compensate for the fact that there is less room to store data on tracks near the center of a disk or platter.  The hard disk's head "precompensates" for the higher density of data on these smaller tracks by increasing the strength of the magnetic signal on these tracks.  Some disks allow only a single setting for WPC which kicks in at a specific track number, but most newer hard disks either continually increase the magnetic strength when writing to disk or provide (and need) no compensation.

See also: hard disk, track, platter


write-protect

Write protection is the application of a measure to any writable storage medium to prevent data from being written to it.  Write protection usually refers to floppy disks.  3-1/2" floppy disks can be protected against accidental writes by closing a small window on the disk by sliding the tiny black tab designed for the purpose over the window.  5-1/4" disks use a different type of write protection.  These disks have square notches in the sides of them, and covering this notch with adhesive tape of any kind will prevent it from being written.

Hard disks can also be write protected, but this requires special software and in most cases this kind of protection isn't practical since Windows needs to be able to write to its swapfile quite frequently on most systems with less than 12Mb of memory.

See also: floppy disk


WYGINS

What You Get Is No Surprise (also WIGGINS); software acronym; a play on WYSIWYG.

See also: WYSIWYG


WYSIWYG
WYSIWYG, WYSIWYP

What You See is What You Get: refers to a screen that displays data exactly as it will appear on another computer or printout; or, less commonly, used to alert users to the fact that the software is exactly as it appears with no hidden features, bugs or extras not clearly visible to the eye.

Less common variation: What You See Is What You Print (WYSIWYP)

See also: word processing, desktop publishing, scalable font, line art, metafile, WYGINS


x-, y- and z-axes and coordinates
x-, y- and z-axis, x-y-z coordinate

These leftovers from high school geometry are commonly used to refer to positions on the screen.  The computer screen is divided into sectors, each sector represented by a pixel.  The x-axis is the division of sectors left to right on the screen, and y-axis is the division of sectors up and down.  A pixel in the center of a 640x480-pixel screen (the standard resolution used on most home computers) has an x-y coordinate of 320,240...320 pixels across from the left and 240 pixels down from the top.

The z-axis refers to depth, and is only used with representations of three-dimensional objects.  If the monitor was actually a holographic cube of 640x480x320 pixels in depth, the z coordinate would be 160, halfway back from the front of the screen.

Axis is the plane, or directions, in which the segments are numbered.  For example, the x-axis is usually left to right.  The coordinate is the exact location on one or more axes of a given point.

These terms are also used to refer to the location of any item on a two or three-dimensional grid divided up into segments, such as a chart, graphical image or playing field in a game.  The squares on a chess board, for example, could also be defined by their x- and y- axes.

See also: image, bitmap, resolution, sector


xBase

A generic term used to refer to any database or database management software which is compatible with the industry standard dBASE format developed by Ashton-Tate.  Packages that use the dBASE file format are said to be xBase products, and there are literally tens of thousands in use.  dBASE is currently at version V (5); the base industry standard for xBase is dBASE III compatibility.  dBASE was the first widely-used database products to provide full relational database capability on the PC.

See also: database, dBASE, Ashton-Tate, relational database


XENIX

A variation of the UNIX operating system created by Microsoft for IBM compatibles.  Not in popular use now with the availability of the free Linux and FreeBSD UNIX clone systems, and far less supported than Microsoft's Windows NT operating system which was designed for similar markets.

See also: UNIX, operating system, Linux, Windows NT


X-Windows

This is "Windows" for UNIX operating systems.  X-Windows is a Mac/Windows-type interface developed at MIT for enhancing the usability of UNIX, essentially bringing it up to speed with the GUI standards on most other platforms.  The source code for the interface itself is free to the public, and there are both free and commercial versions of X-Windows available.  X-Windows is used as the base for nearly all UNIX-based GUIs.

See also: graphical user interface (GUI),  UNIX, operating system, interface, Massachusetts Institute of Technology (MIT), source code


zap

Three meanings.  In hacker slang, to erase or destroy (e.g. "I zapped all my copies of that game yesterday when it refused to let me win.") In hacker usage, refers to a program that allows direct byte-level editing of a binary file (also known as a hex editor).  In database management, to permanently erase records or parts of records in a database file.

See also: database, hexadecimal, hacker, byte


zero file

Two meanings.  In general computing it refers to a file with no data (or zero bytes).  This file actually does take up space though, since all files must use at least one sector of the disk on which they reside.  On the Internet, a zero file refers to the first file of a binary posting and is used to describe the software being posted.

See also: sector


Zork

A seminal computer game.  The second of the great early experiments in computer fantasy gaming; see ADVENT.  Originally written on MIT-DM during the late 1970s, later distributed with BSD UNIX (as a patched, sourceless RT-11 FORTRAN binary; see retrocomputing) and commercialized as `The Zork Trilogy' by Infocom.  The FORTRAN source was later rewritten for portability and released to USENET under the name "Dungeon".  Both FORTRAN "Dungeon" and translated C versions are available at many FTP sites.  [Source: The Jargon File 3.0.0]

See also: role-playing game, Hack, FORTRAN, C, UNIX


ZIF
Zero Insertion Force (ZIF)

Refers to the type of socket, usually called a ZIF socket, used by most newer pin grid array type CPU chips (80386 and higher) to connect them to the motherboard.  These sockets have a grid of holes where each pin of the chip fits loosely, and the connection is made by the use of a lever which clamps the contact points in the socket to the pins so they can connect with the rest of the system.

See also: pin grid array (PGA), motherboard, central processing unit (CPU), 80x86


ZIP

A generic term referring to both the process of compressing files for storage or transmission using PKZIP or a similar form of archiving software, and to the programs designed to create these archives.  PKZIP, created by PKWARE, Inc.  is the industry standard and was developed on the IBM-PC.  Info-Zip is a free, PKZIP compatible library of code used in a wide range of programs to unpack PKZIP archives.

See also: PKZIP, data compression


File Extensions and their Meanings
File extensions and meanings

Introduction

1ST	Usually a text file with the name README.1ST.  Occasionally chapter files for electronic books or data files used by programs

386	A device driver used by Windows (pre-95) for enhanced mode functions

8BF	Photoshop-compatible "plugin filter" program file designed for graphics processing

_DD	Norton Disk Doctor "stray data" file; see CHK

$$$	Temporary work file or Programmer's File Editor backup file; nearly always erasable

A

AD	An After Dark screen saver module

ADI	AutoCAD plot file

AFM	Adobe PostScript font support file; contains information about the font

AIF	With AIFF, UNIX-based sound file format used on the Internet

ALL	WordPerfect printer and font definition file

ANI	DOS: low-resolution animation file; Windows: animated cursor image file

ANN	An annotation made to a Windows helpfile

ANS	ANSI graphics file; viewable by typing TYPE <filename> at the DOS prompt; usually created by bulletin board operators to advertise their board

ARC	Compressed, archived file, processed usually with PKUNPAK.EXE (PKWARE; product; difficult to find now as the ARC file format is obsolete)

ARJ	Compressed, archived file created with ARJ.EXE by Robert K. Jung

ART	Usually a graphics file for First Publisher

ASC	ASCII text file; seldom used any more; TXT is more common

ASM	Assembly language source code

ASP	Procomm script file

AU	Audio data file; Sun Microsystems format; common on the Internet due to portability

AVI	Microsoft Video for Windows animation file

B

BAK	Backup file; nearly always safely erasable

BAS	Program or source code in BASIC programming language; requires the proper BASIC command interpreter to run; not all interpreters are the same and many produce unexpected results with incompatible BASIC code

BAT	DOS batch file; a series of commands executable just as if they were typed at the command prompt; the simplest programming language for IBM-compatibles

BIN	Binary data file; usually an "overlay" file used at certain times by a given program; on some systems BIN files are actual programs

BIT	Lotus Manuscript graphic file

BKP	A backed-up file; almost always safely erasable

BLD	BSAVE'd BASIC binary file.  These are loaded with the BLOAD command; seldom used now

BMK	Bookmark information from a Windows helpfile

BMP	Bitmapped graphics file used mainly with Microsoft Windows

C

C	Source code for a C language program

CAB	Compressed, archived binary file used by Microsoft for distributing software

CAL	Calendar file; data file used by several programs, in Windows almost always used by Windows Calendar

CAT	Master catalog file used with MSBACKUP (MS-DOS 6.0+); critical to the backup set

CDR	Graphics file created by CorelDraw

CFG	Configuration file for a program

CFN	Configuration file for a program

CGM	Computer Graphics Metafile used by MS Publisher and other compatible programs

CHK	"Stray data" file produced by DOS CHKDSK.EXE.  These files are written to the root directory when you convert lost chains to files.  Best kept unless system is behaving flawlessly and all files are accounted for

CHT	Chart file from one of several charting programs or a "cheat" file of tips for a game

CLP	Windows program data (any type) which has been copied to the clipboard and saved to disk as a file

CNF	Configuration file; either contains setup data created by the program when installed or the user's personal settings

CNT	Windows 95 helpfile topic list file

CNV	Converter program used by other Windows programs to convert one type of data to another type

COB	Source code for programs written in the COBOL language

COD	Object code file used by compilers

COM	"Command file"; a DOS-only program consisting of a series of instructions that can be executed directly by COMMAND.COM and does not need sophisticated control over the hardware

CPI	Code page information files for foreign character sets used by MS-DOS; rarely needed

CPL	Windows control panel "applet" or mini-program; not runnable from the command prompt or by double-clicking

CPS	Antivirus checklist file, probably left by Microsoft Antivirus.

CPT	Macintosh format Compact Pro compressed archive file

CRD	Cardfile data file for Windows Cardfile; also used by other database programs

CRF	Cross-reference file

CUT	Halo I, II, III graphics file from Dr. Halo

D

DAT	data file; used in hundreds of applications for various purposes

DB	Paradox database file

DB2	dBASE II database file

DB3	dBASE III database file

DB4	dBASE IV database file

DBF	Database file, usually compatible with or created by Ashton-Tate's dBASE

DCT	Dictionary file; usually contains the word list

DEF	Definition file; used for a variety of purposes by different programs

DEV	Device driver file; also used in various forms by programmers to indicate "development"

DHP	Dr. Halo PIC graphics format file

DIB	Device-independent bitmap graphics file; used mainly by Windows

DIC	Dictionary file used by a spelling checker

DIF	Data Interchange Format ASCII files used by spreadsheets, or differential backup catalog file used by Microsoft Backup

DIR	Usually an Mscreate.dir file used in installing Microsoft Windows NT or Windows 95 products

DIZ	Text file found in PKZIP-compressed software that automatically generates a description of the software when it is viewed on specially-configured bulletin board systems (usually called FILE_ID.DIZ).  These files usually provide capsule information about a program and can save a lot of test-running, especially with shareware CD's

DJP	Hewlett Packard softfont file for HP Deskjet-compatible printers

DLL	Windows or OS/2 Dynamic Link Library file; a program that requires another program to run.  Unlike DOS OVL files, DLL's can be used by more than just the program they came with

DOC	Documentation text file.  When found in software packages prior to 1995, usually the plain-text manual.  Also represents formatted document files created by a word processor.  1995 and after: when found in a software package usually a Microsoft Word format text file browsable with WordPad or Microsoft Word Viewer

DOT	Document template file used by Windows word processors, particularly Word for Windows

DRV	Hardware device driver file; usually loaded at DOS/Windows boot-up to configure and access hardware components

DRW	CorelDraw graphics file; also used by other graphics programs

DVP	DESQview configuration file

DVR	Device driver file; seldom used any more

DWG	AutoCAD drawing file

DXF	AutoCAD graphics file

E

EPS	Encapsulated PostScript data file usually used by desktop publishing programs; more often used now to provide documents via the Internet which can be viewed on many platforms

EXE	Executable program file used by DOS, Windows or OS/2

F

FAQ	Frequently Asked Questions text file

FLC	Compressed AutoCAD animation file

FLI	AutoCAD animation file

FLT	Filter data file; used by many different types of programs

FMT	Formatting file used by dBASE III

FNT	Font file; various formats depending on the program

FON	Bitmapped font file used by Windows (bitmapped fonts get "jaggy" at large font sizes and often have a fixed set of allowable font sizes)

FOR	FORTRAN language source code file

FOT	Windows configuration data file for TrueType (TTF) fonts

FOX	FoxBASE database file

FRM	Form; either a blank form template or a saved, filled out form

FTG	Windows Help database file created by a maximized Full-Text Search; usually erasable, particularly if they take up a great deal of space

FTS	Windows Help database file created by a Full-Text Search; usually erasable, particularly if they take up a great deal of space

FUL	Full backup (complete contents of a disk) catalog file used with MS-DOS 6+ Backup

FX?	 FXS, FXD etc. files are datafiles used by Winfax/Winfax Pro. Outdated FXS files can nearly always be deleted

G

GDI	GEM Metafile

GID	Usually a Windows 95 helpfile data file that stores the keywords and user information for a specific HLP file

GIF	CompuServe Graphics Interchange Format graphics file

GRP	Windows Program Group data file; stores information about icons and special execution instructions for Windows programs

GX1	Show Partner graphics file

GXL	GRASP Graphics file format often used for game animation

GZ	ZIP-compressed archive file using GZIP or a compatible program; a form of compression used mainly on UNIX systems but becoming popular on the Internet.  Might also be preprocessed with tar

H

H	C programming language "header" file

HLP	Help file. DOS program HLP files may or may not be formatted text; in Windows and OS/2 these are always specially-formatted, compiled hypertext similar to this file

HNT	Hint or "cheat" file from a game

HPF	Hewlett Packard HP/PCL printer softfonts, usually created by Bitstream

HPG	Hewlett Packard Graphics Language (HPGL) file

HGL	Hewlett Packard Graphics Language (HPGL) file

HQX	Macintosh-format BinHex-encoded binary file designed to allow transmission of Mac files to other platforms

HST	Usually a text file showing the history or usage log of a particular program

HTM?	Hypertext Markup Language (HTML) file; a World Wide Web-formatted page

HYC	Hyphenation list file for WordPerfect

I

ICE	Archive file compressed by LHice or compatible software

ICO	Icon graphics file used by Windows or OS/2

IDF	Configuration file used by Windows 95 and some other Windows programs

IDX	FoxBASE database index file

IFF	Deluxe Paint II graphics file

IMA	Image file; possibly a disk image created by a disk copy program; has many uses

IMG	GEM Paint graphics file or Atari ST metafile which can often be used by desktop publishing programs; also many other uses

INC	Incremental backup file used by Microsoft Backup, also a programming file

INF	Information file, usually a text file; in DOS, usually a text file that describes a program; in Windows, a program used in the setup process or by a specific program to store certain parameters

INI	Windows initialization file; stores the user's personal settings for a program

ISF	IBM image support facility file

J

JIF	JPEG (Joint Picture Experts Group) compressed graphic image file

JPG	JPEG (Joint Picture Experts Group) compressed graphic image file

K

KEY	Keyboard macro definition files, or a file indicating the state of registration of a piece of software

L

LEX	Lexicon, thesaurus or dictionary file used by a grammar or spelling checker or online thesaurus

LBM	IFF graphics file used by Deluxe Paint and others

LBR	Ancient type of compressed file created with text instructions; once used on the World Wide Web

LIB	Library file used by a computer language compiler

LNK	Windows 95 shortcut information file used by the Start menu; also link file used by some compilers

LOG	A logfile of information about a specific program, user, or activity within a program

LST	Text file usually consisting of a list of files contained in a software package

LTR	Letter file used by word processing programs

LZH	Compressed archive file created by LHArc or LHA.EXE

M

MAC	MacPaint graphics file or a macro file

MAN	File that contains the manual for a program.  This is usually in the form of a text file.

MDB	Microsoft Access-compatible database file

ME	Usually a text file with the name READ.ME (see 1ST)

MID	Standard MIDIfile Format (SMF) song file

MIM	MIME-encoded binary file attached to USENET postings and email

MME	MIME-encoded binary file attached to USENET postings and email

MNU	Menu data file (usually saved from personalized settings) or a mouse menu configuration file

MOD	File to support data exchange between DOS and Windows; also a sound or song file made by rearranging a collection of sound samples

MOV	Apple QuickTime animation file

MOZ	Short for "Mozilla", a Netscape Navigator cached file; safely erasable if not in a subdirectory of the currently-used copy of Netscape

MP2	MPEG (Motion Pictures Expert Group) audio sound file

MPG	MPEG (Motion Pictures Expert Group) motion picture file or MPEG audio sound file

MPE	MPEG (Motion Pictures Expert Group) motion picture file or MPEG audio sound file

MSP	Microsoft Publisher document file

MRB	Multi-resolution bitmap file; used by Windows Help to permit accurate view of helpfile graphics on nonstandard video displays; not usable elsewhere

MVB	Windows helpfile with embedded video and/or database

N

NAM	"Name file", used by many programs, most commonly Print Shop

NDX	dBASE-compatible database index file; used by thousands of programs

NEW	Update file; usually WHATS.NEW, a text file containing new product information or information about new features in an existing product

NG	Database file for Norton Guides (text databases; usually DOS helpfiles)

NOT	Usually a text file "note"

NOW	Almost always a README file; so named to indicate its urgency

NTX	dBASE-compatible database index file

O

OBD	Microsoft Office 95 binder file

OBJ	Object source code file; used by Pascal and other object-oriented languages

OLD	File that has been backed up and renamed to indicate its status as "old"er than another file (probably in the same directory) with the same name)

OVL	Overlay file; part of a program which cannot be loaded into memory at boot due to DOS memory restrictions

OVR	Usually an overlay file; part of a program which cannot be loaded into memory at boot due to DOS memory restrictions

P

P	Usually Pascal programming language source code

PAK	Compressed archive file created by NoGate Consulting's PAK.EXE

PAL	Palette file; contains color palette information for the graphics program which generated it

PAS	Pascal programming language source code file

PCC	Compressed PC Paintbrush (Z-Soft) graphics file; not Windows Paintbrush compatible

PCD	Kodak Photo-CD format graphics file

PCX	PC Paintbrush (Z-Soft) graphics file; Windows Paintbrush compatible

PDF	Printer Definition File or Portable Document Format (Adobe's Acrobat Reader) document or hypertext file

PDV	Microsoft Paintbrush device driver file

PDX	Paradox database file

PBM	Portable bitmap format graphic image

PGM	Program binary file, usually an overlay; also portable greymap format graphic image

PGP	A Pretty Good Privacy encryption string file used for creating or decoding PGP-encrypted data

PIC	Lotus graphics file, or graphics file used by PC Paint+, GRASP, MacDraw, Degas and others

PIF	Windows or OS/2 program information file; a configuration file for running DOS programs within Windows or OS/2.

PIM	Permanent IMage file used by some graphics programs; used in some programs (usually Personal Information Managers) as a database file

PIT	Older format Macintosh PackIt compressed archive file

PL	Perl language generated script file; could appear identical to an HTML-format file

PNG	Portable Network Graphics format graphic image file

PNM	New Print Shop "name file"

POG	New Print Shop graphics file

PPM	Portable pixmap format graphic image file

PPT	Microsoft PowerPoint presentation file; browsable using the free Microsoft Windows PowerPoint viewer

PRD	Printer definition file; this extension is used by many DOS text editors and word processors, most notably WordPerfect

PRG	Programming source code (any language) or program file from Atari ST/STe/TT

PRN	Usually a text file formatted for printing

PRS	WordPerfect printer definition file

PRT	Data file, usually text, designed or saved by a program for printing

PSO	PostScript Page Description Language (PDL) printer Bitstream softfont file

Q

QT	Apple QuickTime video animation file

R

RA	RealAudio compressed sound file

RAR	RAR format compressed archive file

RAS	CMU raster image format graphic image; also a configuration file used by remote access software

RAW	Either a "raw" sampled sound or a RAW-format graphic image

RC	List of USENET newsgroups compiled by a newsreader program

REC	Windows Macro Recorder file

REG	Registration information file, usually for a Windows program; used in installation to configure the program for proper interaction with Windows and other Windows programs

RGB	Graphic image format used on some UNIX-based Internet sites

RLE	Run-Length-Encoded compressed graphics file: often used as Windows start-up screens

RTF, RTX	RichText formatted text document

S

SAV	File that has been backed up or a saved position in a game

SCR	Script file used by telecommunications software, task automation software or a text or graphics from a screen capture program

SCT	Lotus Manuscript screen capture text file

SCR	DOS: either a screen image captured and saved by a screen capture program or a graphics image, probably used by a game; Windows: a screen saver program file

SCX	Graphics file for RIX/EGA and ColoRix programs

SDA	Descriptive information file for SDN compressed archives

SDN	Compressed archived file distributed by SDN (Shareware Distribution Network) International.  Unpacked using PAK.EXE

SDR	Printmaster "name file"

SET	Backup set file used with Microsoft and Norton Backup; various other uses

SFL	Hewlett Packard HP/PCL-4 bitmapped softfont file (Landscape orientation)

SFP	Hewlett Packard HP/PCL-4 bitmapped softfont file (Portrait orientation)

SFS	Hewlett Packard HP softfont file indicating a screen font

SHP	Printmaster graphics library file

SIG	A signature; either a short message file attached to the end of email or USENET posts or a configuration or registration file for a program

SIT	Macintosh format StuffIt compressed archive file

SK	SideKick Plus (DOS) utility program overlay file

SND	Sound file; used by several applications

SQL	SQL-format database file

STF	Setup information file used by Microsoft program installer; not always safely erasable; may be needed for partial installation and uninstallation

STY	Style sheet for WordPerfect

SYS	Device driver file or, in the case of SYS files in the root directory, configuration files for system boot

T

TAR	Tape ARchive file; usually created on a UNIX machine.  Tar allows several files to be "chained" together for ease of transportation, especially with large numbers of small files (saves the user having to type in multiple file names at the command prompt)

TBK	Windows ToolBook program file; needs the ToolBook runtime library to work

TGA	Targa-format graphics file; all-text information, can actually be read and understood

THN	"Thumbnail" file; a reduced-size sample usually of audio or graphics data

THS	Thesaurus file for WordPerfect and other word processors

TIF	Tagged Image File Format graphics file; used as a high-resolution picture format for transporting graphics data across platforms

TMP	Temporary work file; almost always erasable; if still in use the system will not permit them to be erased

TOC	Table of contents file used in many different types of programs

TOS	Program file used by the Atari ST/STe/TT

TRM	Terminal definition file used by Windows Terminal and other DOS terminal emulation programs

TRN	Translation file; used to translate one type of data for use in another program, translation tables for keyboard layouts for different countries, or configuration information for foreign-language use of a program

TST	"Test" file; used by many different applications

TTF	TrueType format font for Windows, OS/2 or Macintosh

TUT	Tutorial file; could be any data type (usually text)

TXT	Plain text file

U

UC2	Compressed file archived using UltraCompressor II from Ad Infinitum

UPD	Update file; usually a text file containing new product information or program usage history

UU?	Uuencoded binary file; a binary file converted to text in a form that allows it to be shared via USENET or email

V

VBX	Microsoft Visual Basic control file; similar to a DLL except exclusively designed for Visual Basic.  Contains data relating to the layout of specific controls on the screen

VOC	SoundBlaster audio sound file

VXD	Device driver file used by Windows 95 or newer

W

WAV	SoundBlaster audio sample file

WB2	Quattro Pro spreadsheet file

WBT	A batch file program used by Norton Desktop or WinBatch

WK?	Lotus 1-2-3 spreadsheet file; number represented here by ? is the 1-2-3 version number

WKE	Lotus 1-2-3 educational version worksheet file

WKQ	Quattro spreadsheet file

WKS	Lotus 1-2-3 spreadsheet file

WMF	Windows Metafile graphics format file

WPD	WordPerfect data file

WPG	WordPerfect Graphics file for version 5.0 and later

WPK	WordPerfect keyboard macro file

WPM	WordPerfect macro file

WRI	Formatted text document created by Windows Write

WRK	Lotus Symphony spreadsheet file; used by other compatible spreadsheets

X

XL?	Microsoft Excel spreadsheet file (XLA, XLB, etc.)

XTP	Xtree overlay file

XXE	Xxencodedbinary file (seldom used now)

Y

Z

Z	ZIP-compressed archive file using GZIP or a compatible program; a form of compression used mainly on UNIX systems but becoming popular on the Internet; also a compressed file used in many Windows software installations

ZIP	Compressed archive file created using PKZIP or a related program which uses PKZIP's file format.  Also a tutorial data file used by Quicken

ZOO	Compressed archive file created by ZOO.EXE; seldom used


Prior to Windows 95, all files used by DOS and Windows 3.1/3.11 were limited to eleven characters, or eight characters, a period, and a three-character "extension".  With literally millions of programs created for DOS and Windows, this three-character extension business eventually got pushed to its limit, and in truth it was always a headache for developers.  After all, how can you effectively communicate the meaning of a specific file or file type in just three characters?

Windows NT and Windows 95 have finally broken through this limitation (years after it was reduced or eliminated on other operating systems) and files can be given much longer file names that can be used to accurately describe what a file is and what it does.

At a certain point in everyone's computer education, they discover that it pays to know the meanings of specific file extensions.  It usually comes at a time when the hard disk is full to bursting and files have to be erased…but which files?

Heres a guide to more than 250 common file extensions for DOS, Windows and Windows 95, the programs which use them, and what the specific file types are for.  As for what to erase…that's pretty much up to you.


Introduction
Instructions

Please read this disclaimer first

General usage instructions

Copying and pasting definitions

Terms not found in the lexicons


General usage instructions

PC/Internet Lexicon is offered as an aid to understanding computing and Internet terms.  Its use is very simple.

1. Either select a lexicon to browse by clicking one of the bars on the Contents menu or by selecting an item from the Lexicon drop-down menu.

2. Click the first letter of the term you are searching for on the alphabet bar.  Unfortunately, the lexicon is not equipped to handle "fuzzy" searches unless you have special software designed to allow these searches with Windows help tools, so you'll have to be accurate about at least the first letter.

3. Scroll down the screen until you come to the term you are looking for.

4. Click on the term and a box with its definition will pop up.

5. Where appropriate, related terms will be available to browse by clicking the highlighted words in the pop-up box.

6. If you do not find the term you are looking for, either try another lexicon (the term may be included in a different section) or click the Search button to perform a keyword search.  If you need help performing the keyword search, select the Advanced tips item from the Lexicon menu for walk-through help with this very powerful feature.

TIP: This lexicon contains a pop-up right-click mouse menu to prevent having to access the drop-down menu or contents to select a lexicon.

TIP: The next topic is a hidden Easter Egg.  That means we're not going to tell you what it is or how to find it, but you might find it useful.

IMPORTANT NOTE: This version may report errors when browsing some highlighted terms in the pop-up boxes.  Terms reporting errors are available from the registered and retail versions only.


Eliminate the splash screen by launching the lexicon file, not the menu.  Hey, it's freeware...

time as we know it will cease to exist in the year 2012

many tribes and seers have echoed the same prediction

are you ready for a time you never met before?

Keeley said that time is gravity; I say he's right

looks like we're about to master gravity...


Disclaimer

Neither the authors nor Dynamic Living Media, its agents or principals make any warranty, expressed or implied, regarding the accuracy of the information contained in this software.  We have attempted to make this a definitive work; we do not warrant our success in doing so.

Please note that many definitions and suggested links may reflect the bias of the author(s).  In most cases, every attempt was made to provide logical links to the all related topics.  However, there are some instances in which links and definitions appear which the user may feel are of questionable value or taste.  The author(s) of original material for this document were instructed when creating material to side with the projected needs of the user rather than for sheer objectivity to counterbalance what Dynamic Living feels is an anti-user bias in the computing industry.

Due to the volatility of computing terminology, no guarantee can be offered that the definitions for the terms offered, nor any information herein that is not directly related to Dynamic Living Media or the authors of this document, will be accurate and pertinent to the situation faced by the reader or the needs of the user of this software.  Users may quote this source as a reference provided they agree to assume all liability for any damages which may result from erroneous or improper information which is not the direct responsibility of Dynamic Living Media.  Users may quote terms attributed to other sources providing the appropriate attribution is included in the text of any resulting document.

The disavowing of legal responsibility in this disclaimer extends to cover all parties contributing to, and all authors, publishers and other principals involved in creation of, reference documents and/or other sources used in the creation of this software.


Copying and pasting
Copying and pasting definitions

Windows 3.1/Windows for Workgroups and Windows95:

Windows 3.1/Windows for Workgroups will not allow you to copy information from popup help topics.  Unfortunately, all but a handful of the definitions in PC/Internet Lexicon are popups.

There is a rather clumsy workaround for this, however.  Here are the steps:

1. Click the term or acronym to pop up a definition

2. Click again to close the pop-up window

3. Click the History button to display a list of the topics you have browsed.

4. Select the term or acronym you wish to copy to the clipboard.  The definition will then be displayed in a normal help window

5. You can now click the blue text at the top of the window to pop up the copy-to-clipboard dialog, and copy-and-paste can proceed normally.

Expert mode (Windows 95 only)

If you have Windows 95, the new Windows Help will allow you to copy definitions from pop-up windows which are displayed when you click on a term or acronym and still have the popup window open.  This is something you can't ordinarily do, and it only works in a "secondary help window".

This feature only works with Windows 95.  This feature can cause novice users, so it is offered as an "expert tool" because activating this feature opens a second lexicon window removes the menus from your main index window.

Please remember to honor the authors' copyrights when inserting these definitions word-for-word into other documents.

The  expert mode can be used by:

1. Selecting the expert-level indices from either the Lexicons drop-down menu or the right-click mouse menu

2. Selecting a lexicon and subsequently a definition from the new "secondary" lexicon window

3. Copying the text to the clipboard using the Ctrl+C keys.  (Press and hold Ctrl while the popup window is open and tap C.)

4. Pasting the text into a document using the usual methods.

NOTE: You cannot copy the bitmaps (graphics) using this method.  All that can be copied is the text.


For terms not found in the lexicon

This reference is quite rich, but by no means complete.  It was impossible to include the thousands of computer-related terms that could have been added here without making the tool too difficult to manage as a Windows helpfile.  Therefore, it's likely that many terms you expect to find in this lexicon simply won't be here.

There are two possible approaches you can take with an unfound term.  The first is to perform a keyword search of the helpfile using the Search function built into Windows Help.  There are several thousand terms listed, but hundreds more were not included in the main indexes and are searchable as keywords.  Follow the instructions in the Copying and pasting topic to do a more thorough search.

If you have Windows 95, you can do a full search of every word in the help tool, including words which were never given definitions.  It is often possible to browse topics containing the word you are looking for and figure out the meaning of the word by the context in which it is used.

The final approach is to try a World Wide Web search of one of the many dictionaries and acronym lists available online using the Web page supplied with this lexicon.  The search engine will access several databases (not all of them at once, unfortunately) and with any luck one of them will contain the term you are searching for.  Unfortunately you will need to be online in order to use this resource.


Licensing information

Microsoft Windows™ and Windows 95™ are registered trademarks of Microsoft Corporation.  Dynamic Living Media is not affiliated in any way with Microsoft Corporation except as licencees and users of their products.  The Internet Lexicon, PC Lexicon, and PC/Internet Lexicon are copyrighted 1995 Dynamic Living Media.  All files included in this archive are the copyrighted property of DLM except where noted or accredited.

IMPORTANT NOTE:	If you do not agree to the terms of this license, do not use this software.
Terms of your software license:

(Legales with English subtitles; click the BACK or CONTENTS button when you've had enough)

1. This license is limited to the terms and conditions described herein.  Its permissions extend for the life of the license.  Its prohibitions and restrictions extend for the life of the copyrighted work or two years following the release date of the software, whichever comes first, except where noted.

Plain English

2. As a paid user you are permitted to install and use this help tool, henceforth known as  or "the software", for personal use on a single computer and to make one (1) copy of the distribution disks and two (2) copies of electronically-distributed software for archival backup only.  If two copies of the original software exist in your possession, at least one copy must be stored a minimum of one hundred meters from both the original and the first copy.

Plain English

3. If you do not intend to register this software, or you are in possession of a copy of this software which has not been purchased through an authorized Dynamic Living Media distributor, your possession of this document or any part of it is in violation of copyright.  You must erase this software and all copies of it in your possession from your computer immediately.  Distribution of the software in this package except where noted without the expressed written consent of Dynamic Living Media is strictly prohibited and will be enforced.  Any act which consists of making this software publicly available via exchange of data in physical or electronic form may constitute criminal fraud.

Plain English

4. No time limits are applied to the use of the software on the disks supplied with your installation package except where noted in the documentation itself.

Plain English

5. All benefits, restrictions and prohibitions outlined in the license are transferrable.  The copyright holder reserves the right to deny transfer of license for any reason.

Plain English

6. All restrictions on copying and distribution of the software become null and void two (2) years or seven-hundred thirty (730) days after the release date, at which time all software whose release date is greater than two (2) years old may be freely distributed under the terms of the copyright.  This condition applies to all software bearing the Dynamic Living Media copyright, either visibly or encoded as part of a binary file.

Plain English

7. WARRANTY: The software is provided as operational and usable within the parameters described in the packaging and requirements on all systems which fall within the standards listed on the package.  Neither Dynamic Living Media nor its agents or distributors shall be liable or responsible for the failure of this product to perform as advertised on equipment which does not meet the criteria described on the package.  Distribution disks are warranted against failure for a period of 30 days and may be returned for repair or replacement before that period without charge.  Under no circumstances shall Dynamic Living Media, its agents or distributors be responsible for any inability to use this product as advertised due to nonstandard software or hardware configurations including but not limited to third-party menuing systems, system software and hardware. If one or more of the disks in the set is faulty, or refuses to install within 30 days, it/they may be returned to Dynamic Living Media for replacement.

Plain English

8. LIMITATION OF LIABILITY:  Under no circumstances and under no legal theory, tort, contract, or otherwise, shall Dynamic Living Media be liable to you or any other person for any indirect, special, incidental, or consequential damages of any type including, without limitation, damages for loss of goodwill, lost productivity, computer failure or malfunction, or any and all other commercial damages or losses which are not directly due to negligence or malice on the part of Dynamic Living Media as covered by legal definitions of reasonable care.  This limitation of liability shall not apply to liability for death or personal injury to the extent applicable law prohibits such limitation.  Some jurisdictions do not allow the exclusion or limitation of incidental or consequential damages, so this limitation and exclusion may not apply to you.

Plain English


License term 1
Your rights to use the software itself never expire, and the do's and don'ts will be in effect for decades to come except for your right to share the software with others, which you may do two years after this software's release date.  "Software package" means this helpfile specifically and all files except for any free or freely copyable programs included as part of this package.  See README.TXT for further details.

As a matter of policy, Dynamic Living Media downgrades all software labelled "commercial", "retail" or "shareware" to freeware after two years, meaning that if this is 1998, you're probably off the hook completely as far as needing to pay for this version.  (Check the dates on the files in this program's directory if you're not sure.)


Big deal.  It's free software.  Just remember that we wrote it, and while you can share it, you can only share the complete package, not parts of it.


Once again, big deal.  You have nothing to worry about as long as you do not modify the software or claim all or part of it to be your work.


Your right to use the materials you got with this help kit, and that you will get in future from us via email or FTP, never expire.  Use it as long as you like.  Some of our products have expiry dates; this one does not.


This is part of our commercial license.  Don't worry about it.


We at Dynamic Living believe that freedom of information is more than just a right.  It's a principle.  All Dynamic Living Media information products become free software two years after the release date.  (The release date for Dynamic Living Media products is the same as the date on the files themselves.)  It doesn't matter with this product because it's freeware.

We encourage all publishers to adopt similar free-distribution clauses for their software so that the gap between "information haves" and "information have-nots" can be reduced.  Let's face it...after two years on the market, a publisher isn't going to make much money on an old version of the software anyway.


Since technically there is no package, there is also no warranty.  We don't warrant our freeware releases in any fashion.


If it's our fault, we'll do everything in our power to fix it.  If it's not our fault, we need this disclaimer to protect ourselves against people who enjoy frivolous lawsuits.


Acknowledgements
Acknowledgements and credits

Cub Lea and Dynamic Living Media made extensive use of several popular and commonly-available resources in the creation of this package.

The most critical for the Internet lexicon was the Internet Users' Glossary (RFC 1392) which was the source for most of the networking terms used here.  Information regarding this document and the sources used in its creation are listed in the acknowledgements topic highlighted above.

The PC Glossary by Disston Ridge, Inc. was also consulted often as a source for essential terms and cross-references for the general computing lexicon.  We also thank Disston Ridge for setting a standard of quality to shoot for, and for providing the inspiration for this work.  We will no longer think of Disston simply as a manufacturer of saws.

An uncredited list of acronyms which circulated on the Internet was source for about 250 acronyms in all categories.

The Jargon File version 3.0.0, our favorite source for information on more arcane subjects and definitions, was consulted and quoted frequently; we can't match the style and wit used here and strongly recommend this document to all our readers.

GLOSSARY.HLP, the glossary enclosed with Microsoft Windows 3.1 and produced by Microsoft Corp., was also consulted frequently.  It was used as a skeleton document and a constant reminder of how not to deal with elementary terms critical to novice users; regrettably, early versins fell into the same trap and some remnants of this problem still remain in the product.

Several friends on Internet Relay Chat, (Graham Blake of Denman Island, BC and Damascena Korwen of San Francisco, CA in particular), were - knowingly or not - also instrumental as inspirations for this project.

Cub Lea can be contacted at cublea@cyberstore.ca or on CompuServe at 103076,1667.


Internet Users' Glossary information
Internet Users' Glossary

Network Working Group/G. Malkin/Request for Comments: 1392/Xylogics, Inc./FYI: 18/T. LaQuey Parker/UTexas/Editors/January 1993

Status of this Memo

This memo provides information for the Internet community.  It does not specify an Internet standard.  Distribution of this memo is unlimited.

Abstract

There are many networking glossaries in existence. This glossary concentrates on terms which are specific to the Internet. Naturally, there are entries for some basic terms and acronyms because other entries refer to them.

Acknowledgements

This document is the work of the User Glossary Working Group of the User Services Area of the Internet Engineering Task Force (IETF). Special thanks go to Jon Postel for his definitive definition of "datagram".

References

BIG-LAN "BIG-LAN Frequently Asked Questions Memo", BIG-LAN DIGEST V4:I8, February 14, 1992.

COMER Comer, D., "Internetworking with TCP/IP: Principles,

Protocols and Architecture", Prentice Hall, Englewood Cliffs, NJ, 1991.

FYI4 Malkin, G., and A. Marine, "FYI on Questions and Answers: Answers to Commonly asked "New Internet User" Questions", FYI 4, RFC 1325, Xylogics, SRI, May 1992.

JARGON "THE JARGON FILE", Version 3.0.0, July 1993.

HPCC "Grand Challenges 1993: High Performance Computing and Communications", Committee on Physical, Mathmatical and Engineering Sciences of the Federal Coordinating Council for Science, Engineering and Technology.

MALAMUD Malamud, C., "Analyzing Sun Networks", Van Nostrand Reinhold,

New York, NY, 1992.

NNSC "NNSC's Hypercard Tour of the Internet".

LAQUEY LaQuey, T. (with J. Ryer), "The Internet Companion: A Beginner's Guide to Global Networking", Addison-Wesley, Reading, MA, 1992.

NWNET Kochmer, J., and NorthWestNet, "The Internet Passport:

NorthWestNets Guide to Our World Online", NorthWestNet, Bellevue, WA, 1992.

RFC1208 Jacobsen, O., and D. Lynch, "A Glossary of Networking Terms",

RFC 1208, Interop, Inc., March 1991.

STD1 Postel, J., "IAB Official Protocol Standards", STD 1, RFC

1360, Internet Architecture Board, September 1992.

STD2 Reynolds, J., and J. Postel, "Assigned Numbers", STD 2, RFC 1340, USC/Information Sciences Institute, July 1992.

TAN Tanenbaum, A., "Computer Networks; 2nd ed.", Prentice Hall, Englewood Cliffs, NJ, 1989.

ZEN Kehoe, B., "Zen and the Art of the Internet", February 1992.

Security Considerations

While security is not explicitly discussed in this document, some of the glossary's entries are security related. See the entries for Access Control List (ACL), authentication, Computer Emergency Response Team (CERT), cracker, Data Encryption Key (DEK), Data Encryption Standard (DES), encryption, Kerberos, Privacy Enhanced Mail (PEM), Trojan Horse, virus, and worm.

Authors' Addresses

   Gary Scott Malkin
   Xylogics, Inc.
   53 Third Avenue
   Burlington, MA 01803
   Phone:  (617) 272-8140
   EMail:  gmalkin@Xylogics.COM

   Tracy LaQuey Parker
   University of Texas at Austin
   Computation Center
   Austin, TX 78712
   Phone: (512) 471-2444
   EMail: tracy@utexas.edu


About the editor

 Cub Lea is a freelance writer and hypertext author living in Burnaby, British Columbia.  He can be reached on the Internet at cublea@cyberstore.ca (check the person-finder services if this address is no longer working) or at CompuServe at 103076,1667.


wizard screen 2

This is the next screen of this demonstration wizard.  There are no options to choose from in this demo, so if you understand the concept, continue to the third screen by clicking the Next button.  If you want to review what you have learned, click the Previous button.


wizard screen 3 (last)

This is the last screen of the demo wizard.  Once again, you can return to the previous screen by clicking the Previous button and make any changes you wish to make there, or you can finish the job the wizard is designed to assist you with.


Unavailable definition

This term is not included in this release.  (There are fewer than 20 such terms.)  Consult the registered version for more information.


Unavailable definition

This term is not included in this release.  (There are fewer than 20 such terms.)  Consult the registered version for more information.


Unavailable definition

This term is not included in this release.  (There are fewer than 20 such terms.)  Consult the registered version for more information.