APPENDIX: The Accompanying Files


OVERVIEW OF THE ACCOMPANYING FILES
==================================

Besides the individual chapter text files, ETHAN.ZIP contains all of the
example code, BASIC programs, and assembly language source files used in
this book.  The example BASIC files have names like CHAPn-n.BAS, where the
first part of the name indicates which chapter the example was used in, and
the second part is the listing number within that chapter.  The remaining
BASIC files use more descriptive names, and those are the ones you're most
likely to actually use and add to your own programs.  Likewise, the shorter
assembly language examples from Chapter 12 are in files named CHAP12-n.ASM,
but source code for the complete routines are in files having names based
on the actual routine names.
     The library files named BASIC.* are meant for use with QuickBASIC
version 4.0 or later, and the files named BASIC7.* are for use with BASIC
PDS and VB/DOS.  Files with a .QLB extension are Quick Libraries that you
load along with QB.EXE or QBX.EXE or VBDOS.EXE, depending on your version
of BASIC.  The .LIB files are intended for use with LINK, when you create
executable programs.  There are also a few .BI (BASIC Include) and .MAK
(Make) files used to support some of the programs.  I did not bother to
include separate .OBJ files for the assembly language routines, since you
can easily extract them from BASIC.LIB or BASIC7.LIB if you need them.


STARTING BASIC

To start QuickBASIC and load the BASIC.QLB library, enter this from the DOS
command line:

     qb [program] /l basic.qlb /ah

If you specify the optional BASIC source program name, that is loaded into
the QuickBASIC editor along with the BASIC.QLB library.  The /ah switch
tells QuickBASIC to allow huge (greater than 64K) arrays, which is needed
for some of the demonstration programs.
     If you are using BASIC PDS, start QBX as follows:

     qbx [program] /l basic7.qlb /ah /es

The /es switch is needed for the EMS.BAS demonstration, and it tells QBX to
cooperate with your use of Expanded memory.  When /es is omitted, QBX
assumes no other programs are using EMS, which lets it access that memory
slightly faster.  Since EMS.BAS stores its sample data in Expanded memory,
this option is needed to avoid corrupting EMS memory.  Even if you do not
plan to run EMS.BAS, using /es is harmless.
     If you have VB/DOS you should start it like this:

     vbdos [program] /l basicvbd.qlb /ah /es

Once the appropriate Quick Library has been loaded, you may use the File
Open menu sequence to load the BASIC programs.  Note that with VB/DOS, the
Open menu defaults to a .MAK extension, so you'll have to enter *.BAS or
type the complete name of a BASIC program source file.
     Some of the example programs use BASIC's CALL Interrupt command, and
to run those you will have to quit the BASIC editor, and restart it loading
the default Quick Library that comes with your version of BASIC.  You do
not need to specify a Quick Library name when loading the default library;
using only the /l switch is sufficient.


LINKING

When you compile and link programs manually from the DOS prompt and you
want to use the .LIB libraries supplied with this book, you must specify
the library name manually on the LINK command line:

     link program [/options] , , nul, basic[7] ;

The BASIC7 library works with both BASIC PDS and also VB/DOS, so it was not
necessary to provide a separate BASICVBD.LIB file.  You can also compile
and link from within the QuickBASIC or QBX editors using the menu options. 
When a Quick Library is loaded, the BASIC editor uses the same first name
for the LINK library when it shells to run BC and LINK.  For example, if
you started QBX like this:

     qbx /l basic7.qlb

QBX tells LINK to use a parallel .LIB library named BASIC7.LIB.  But since
there is no BASICVBD.LIB file you must compile and link manually when using
VB/DOS.  If you don't use BASIC PDS you can optionally rename BASIC7.LIB to
be BASICVBD.LIB.  Then when you start VB/DOS as shown above it can specify
the correct library name when it shells to LINK.
     The BASIC editor limits you to using either the Quick Library from
this book *or* BASIC's version that contains CALL Interrupt--you cannot
load two Quick Libraries at one time.  However, you can link with more than
one library when creating an executable program manually.  This example is
for QuickBASIC, and you would substitute QBX.LIB and BASIC7.LIB with PDS,
or VBDOS.LIB and BASIC7.LIB when using VB/DOS:

     bc program [/o] ;
     link [/options] program [other modules], , nul, qb.lib basic.lib ;