ÿ\CL\FL\MODEM3®HY0¯®RM70¯®LL1,.25¯®LM1¯®MDBR¯®RHA ®RM65¯Michael Finley®LD ¯ MODEMS, p. ®PN¯ of ®FP¯®MDNM¯ ®RM36¯ ¯®MDNM¯®RFA Michael Finley * 2096 Dayton Avenue * St. Paul, MN 55104 ®LD ¯612/646-4642 ¯®UL3¯®PT11¯®LS2¯®FR¯®PT4¯®DAm/d/yy¯ ®FR¯®RM33¯ 2,415 words ®FR¯®MDSU¯®PT11¯®LS1.75¯®FC¯A BUYER'S GUIDE TO MODEMS®MDNM¯ ®LM2¯ ®MDSD¯®PT6¯By MICHAEL FINLEY®MDNM¯ ®FL¯ ®RM36¯®PT6¯®IP5,0¯®LL1,0¯®LS1.25¯The proliferation of personal computers in the office and at home over the last dozen years has resulted in the creation of two classes of consumers -- those who have managed to stay abreast of rapid developments in personal computers and those who, because they have not yet made the leap to own or operate a computer, aren't exactly certain what the fuss is all about. ®RFA¯Take the case of modems. Most people know that modems are devices which link computers to telephone lines. Beyond that, the understanding becomes a ®PG¯ ®IP0,0¯bit vague. This is understandable. Telecommunications is a combination of very old technology -- the phone existed before the automobile -- and the latest microchip and optic fiber technologies. There is no avoiding technical terminology about compatibility, protocols, baud rates and duplexes, but there is no great need to understand these things as long as you know where you want to go, and how to get there. ®RFA¯®IP5,0¯Where you want to go with your modem could be just about anywhere. The reasons over 40% of America's 100 million personal computers are now equipped with modems are many, and why modems are the most popular computeral peripheral after hard or fixed disks are many:: ®IP0,2¯* people want to "chat" with one another over computer Bulletin Board Systems (BBSs), or to download public domain or "shareware" software programs from them; * they want to link up to on-line databases such as Compuserve, DIALOG, The Source, Genie, and other computer-driven reference, with answers to every imaginable question; ®PG¯®LS1.5¯ * they want to meet in on-line users groups to talk about their interests, or to play games or engage in other entertainment; * they want to transmit data from home to office, or from office to client; * they want to transmit data compatibly from one brand of computer to another. ®IP5,0¯What all these reasons have in common, however, is the urge to "complete the promise" of personal computing -- to make the individual workstation as interactive and as powerful as possible. Computers put speedy manipulation of data within reach of everyone -- modems link computers together to multiply that power a hundredfold or more. The word "modem" is a combination of MODulator/DEModulator -- electronics-ese for what modems do, modifying a stream of signals so that they are transmittable and retrievable. Put another way, modems act as translators between computer signals, painstakingly making both sides of the conversation understandable to each. Though standards exist amomg modems, there are still myriad varieties, speeds, styles, features and functions available. The good news is that prices are falling, and that high speeds and high reliability are cheaper than ever before. The bad news is it's hard to test-drive a modem before buying it. Prospective modem-buyers need to ask themselves the following questions: ®PT12¯®MDBO¯What do I need to telecommunicate?®MDNM¯ ®PT6¯You need four things: a computer, a phone line, a modem, and a telecommunications software program. Your regular phone line will do -- if you plan on doing intensive telecommunicating, you may wish to have a separate line installed, with a different phone number. Some modems come packaged with, or bundled with, their own telecommunications programs, or with inexpensive beginner's programs such as Bitcom. Many mail order offers include shareware programs on diskette, such as Procomm or Qmodem, which you may pay for if you wish. These programs are of very high quality, and are inexpensive to purchase (under $100) if you choose to pay for it. But you will need some kind of telecommunications program -- and some off-the-shelf packages cost $300, $400, and more. ®PT12¯®MDBO¯How fast a modem do you need?®MDNM¯ ®PT6¯Three years ago, the choices were easy -- 300 bps (bits per second), or slow, and 1200 bps, four times as fast. Today 2400 bps is rapidly becoming a standard, and 9600 bps is inching its way into the marketplace. Of course, speeds up to 19,200 bps (19.2 kilobytes per second) are available for specialized purposes. Unless you are on a very tight budget, do not settle for 300 bps. At that rate, sentences scroll by much slower than you can read. 1200 bps is a bit too fast to read at normal scrolling speeds, but is the favorite speed. 2400 is very fast, and 9600 may be too fast to control. The reason speed is important is that, except for local calls to non-commercial computers, you pay for your time spent on-line. At long distance rates of $.30 per minute, downloading a 20 kilobyte program or 3,500 word document using the usual Xmodem protocol will cost $4.33 at 300 bps, but only $1.06 at 1200 bps, and $.53 at 2400 bps. On the other hand, on-line references like Compuserve charge more per minute for higher speeds -- $6.00 per night-time hour at 300, $12.50 per hour at 1200. But on balance, higher speeds still save you lots of money in long distance charges and connect fees. You can buy a new 300 bps modem for under $50. It is an inexpensive way to break into the world of telecommunications. You may also find that using a 300 bps modem will make you unpopular with some BBSs. Slower modems mean longer stays on-line, which makes it harder for other users to connect. A strong prejudice exists in these electronic communities against slow-poke modems tying up the phone lines. ®PT12¯®MDBO¯Do all computers work with modems?®MDNM¯ ®PT6¯Yes -- from laptop to mainframe, the essential work of computers is easily transmitted as bits. Apples, Ataris, Commodores, IBMs and compatibles, Texas Instruments, AT&T Unix machines, even discontinued machines like Osbornes and Timex Sinclairs can be made to send and transmit. Some computers have greater innate talent for telecommunications. Though the Macintosh is better for graphics applications, the IBM standard is considered superior for modems. 16-bit machines like the IBM PC have greater flexibility than 8-bit machines like the Apple II series, CP/M machines, Ataris and Commodores. Software packages for the different machines vary in quality and cost, but every machine can be made to telecommunicate somehow. Note that there is an increasing trend to package some computers, especially the portable laptops, with internal modems. One reason is that the space is so compact that consumer installation may be difficult; another is that these small computers were made for the road, and modems and traveling go together very well. The popular notebook-sized Tandy 100, packaged with its own 300 baud, Hayes-incompatible modem, was a big-seller; IBM's Convertible, a higher-priced laptop, debuted miserably with its built-in, Hayes-incompatible modem. Newer MS-DOS based portables like the Bondwell 8 and GRiDCase 3 Plus, have followed the Hayes standard with their bundled modems. ®PT12¯®MDBO¯Do all modems work with all computers?®MDNM¯ ®PT6¯No, one size does not fit all. In fact, there are several hundred manufacturers of modems worldwide, and even so-called "clone" hardware varies widely from brand name to brand name. Still, standards do exist. Most computers come equipped or can be equipped with an RS232 serial port, with either 9 or 15 pins, and this is the de facto standard. IBM computers and their clones use it, Apple II and Macintosh use it, and Commodores (most of which use an IEEE-448 interface) can be retrofitted with one. Nearly all modems conform to the Bell 212A hardware standard -- if you see a low-priced modem, make sure it's Bell 212A- or (if you're running at 300 bps) Bell 103-based. ®MDUL¯Avoid®MDNM¯ Bell 113, Bell 202, and the Racal-Vadic standards. Note that Bell standards may not be legal in some countries, however -- if you will be doing extensive overseas telecommunications, you will want at least a 2400 bps modem compatible with something called CCITT V.22. Secondly, an industry standard for communications language exists -- the so-called Hayes standard, after the Hayes Corp., the largest maker of modems and creator of the original Smartmodem®MDSU¯R®MDNM¯. Hayes compatibility is claimed by many modems, but compatibility is often only partial. When buying a modem insist on full compatibility to the Hayes AT command set. And avoid like the plague any modem with zero Hayes compatibility. Not surprisingly, the most Hayes-compatible modems are offered by Hayes. ®PT12¯®MDBO¯What else do I need to telecommunicate?®MDNM¯ ®PT6¯Good question. You also need a telephone with modular plugs (no party line!), the computer itself, communications software, and perhaps a cable and serial port. If you have the Call waiting feature on your phone line, you will want to disconnect it while telecommunicating -- any interruption while on-line will terminate your call. ®PT12¯®MDBO¯What features are important?®MDNM¯®PT6¯ ®MDBO¯External ®MDBU¯vs®MDBO¯ internal®MDNM¯: There are two basic physical types of modems, the external and internal. The external plugs into your serial port using a cable. It is usually a sealed box with LED indicators. An external option seldom seen anymore is the acoustic-coupler design, featuring a telephone handset which cups into the transmitting device. Then there are internal modems, for computers allowing the insertion of cards inside the computer chassis. IBM and Apple, with their open architecture, allow internals, while Macintosh and other sealed systems do not. Internals tend to be $10-20 cheaper than externals, and they involve no cables or serial ports, which also cost money. On the other hand, they are invisible, with no LED indicators to let you know if they are working. Another physical option has recently become available as well -- the portable modem. This handy battery-powered device snaps into the serial port of whatever computer happens to handy, to enables you to call the home office or wherever. It is ideal for companies using electronic bulletin boards to keep tabs on its sales force, or for anyone who wants to travel. The Migent Corp., which introduced the Pocket Modem last year, is selling many thousands, and imitators are beginning to crop up. ®MDBO¯COM1, COM2, etc.®MDNM¯ With most operating systems, more than one input/output (I/O) device can be run at the same time. To prevent confusion, devices must be run from separate ports, called COM1, COM2, COM3, COM4, and so on. If you have a mouse, a modem, and a serial printer, you need to address three COMs. But some modems only offer COM1 and COM2 options. For most people this limitation is not crippling. But if your system is loaded with lots of devices, you may want to purchase a modem enabling COM3 and COM4, along with the basic two. ®MDBO¯Auto-Dial®MDNM¯. A workable modem must also have the capacity to dial for you. You will become impatient very quickly doing it yourself, even with touch tone. This feature is called Auto-Dial. Most modems work with Touch-Tone®MDSU¯TM®MDNM¯ and rotary pulse phones. ®MDBO¯Auto-Answer®MDNM¯. Along with Auto-Dial is the opposite feature, Auto-Answer, also very desirable. Auto-Answer tells your computer to be receptive to incoming calls, and answering it just as if it were a person. Without Auto-Answer you have to be at your computer ready to make all connections yourself. ®MDBO¯Duplex®MDNM¯. Both Full or half-duplex capabilities are necessary in an all-purpose modem. Half duplex means the two parties communicating must take turns; full duplex means both parties can transmit and receive simultaneously. ®MDBO¯Error correction®MDNM¯. A few glitches in a text file -- such as an article or abstract -- can usually be forgiven. But when a single byte on a software program is altered during transmission, the program won't work, and your time will be wasted. Thus nearly all modems transmit data using Xmodem or Xmodem-CRC (for cyclic redundancy check) protocols, which double-check to guarantee that what is being sent is the same as what is received. The usual culprit is "line noise" -- the random clutter occurring on many phone lines, rather like the ringing and tapping and back-echo one sometimes hears on voice phone. To further protect against line noise, some modems come equipped with noise elimination protocols -- the new standard being MNP, for Microcom network protocol. MNP adds cost to a modem, and adds time to the period in which computers link up, or "handshake" -- for a given protocol to succeed, both modems must have the capability. ®PT12¯®MDBO¯Cost.®MDNM¯ ®PT6¯Time was, and not long ago, a good modem cost $300, and the really good ones could cost upwards of $1200. With the advent of foreign-made Hayes-compatible clones, however, prices have been dropping even as speeds have increased and the establishment of industry standards have made lookalikes more and more attractive. The big manufacturers, like Hayes, U.S. Robotics, AT&T and Racal-Vadic continue to offer top quality for the premium price. But their competitors from Korea, Japan, and other places are not far behind in quality, and their prices are very attractive. Many mail order houses are offering 2400 bps modems for about $175 these days, while 1200 bps modems have fallen under the $100 mark -- $79 price tags for brands such as Amazing Things, Everex, and Volksmodem are not uncommon. Remember that manufacturers offering bottom-line products have had to cut corners somewhere. It may be in the tensile strength of the card, or in some subtle electronic quality control aspect invisible to the eye. Modems don't last forever, but they will last five years or so -- ®MDUL¯if®MDNM¯ they are well-constructed. ®PT12¯®MDBO¯Where and how to buy.®MDNM¯ ®PT6¯There are two basic ways to buy modems, from stores and by mail. As stated above, you can obtain a price advantage -- often as much as 30% -- by buying through the mail. But this more than one definition of cost -- and for first-time buyers, the extra cost of buying locally is easily offset by the extra security of knowing you can call when something goes wrong, or you can't make your modem work. If you know what you're doing, order by mail, using a credit card. If you don't, have your local dealer absorb some of your anxieties. Installing a new modem on your own, with no local service rep and no support number to call, and with all the many variations possible in setting your modem, even intelligent people can be made to feel dumb. If it is an internal modem, you will be asked to open up the back of your computer and insert it among all the other electronic intricacies. For many people, this is just too much -- they should buy their modem locally, and have the store install it as well. As for the rest, modems turn ordinary computer users into power users. With a modem "under the hood," the user not only knows the inside of his computer better, but he has opened a million doors to the outer world. Libraries, business networks, friendships, fun, even romance -- all accessible, 24 hours a day, at the touch of a key. ®FC¯# # # ®IP0,0¯®LL0¯ ®RM70¯®LD-¯ ®PT12¯®MDBO¯®FC¯A SENSIBLE FIRST-TIME MODEM®MDNM¯ ®PT6¯®LD-¯ ®FL¯The following is a common configuration of modem features, easily fitted to nearly any personal computer. Costs for such a modem system could range from $75-$225. ®LM1¯®RM70¯®LD-¯ ®CT0,25,45¯®LS1¯®RM20¯®MDBO¯Design: Compatibilities: Baud rate: Features: Modes:®MDNM¯ ®RM70¯®CO2¯®RM38¯®LS1¯External design, with a serial interface, to connect to an RS232 port "AT" or Hayes®MDSU¯R®MDNM¯ command set for software flexibility; Xmodem for error correction; Bell 212A ringing standard 1200 bps Auto-Answer, Auto-Dial COM1, COM2 ®EC¯®LM1¯®LD-¯ ®RM70¯ ®RFA®LM1¯®RM70¯Copyright (c) 1988 by Michael Finley; all rights reserved. ¯