The Silicon Jungle by David H. Rothman

placed in the public domain; you do this after you log on the BBS. MODEM7 is a good example of free software that fills a niche; experts say it’s better than some $150 products. Most free programs are losers for the typical business. They’re either (1) games, useless except for training, (2) unreliable lemons with bugs in them, the software kind, (3) programs that might work but don’t do anything useful, or (4) fiendishly difficult challenges because the instructions are confusing and no one handy knows how to use them. But wonderful exceptions exist. Never thumb your nose at something just because it’s free. In MODEM7’s case you’ll find more happy, knowledgeable users than you will in the cases of many commercial programs. MODEM7-style protocols have become an industry standard. Even big businesses and government agencies, including the IRS, have used MODEM7 for some purposes. It’s influenced the designs of commercial micro programs, which employ similar techniques to facilitate linkups between different brands of communications software. MODEM7 will also get along beautifully with the popular PC-TALK III “freeware” program for IBM micros and some clones. Freeware is low-cost software distributed in many cases by the users themselves; the author may request a “donation”. Granted, MODEM7 isn’t the ultimate. The instructions included on the disk are confusing to the novice—a problem I’ll try to overcome here—and ready-to-run versions aren’t available for every computer system. Some commercial communications software, moreover, is easier to run and can help you talk to more machines. And it may also make better use of the “smart” modems and their software so that your computer can dial up others automatically at 11:00 p.m., when the phone rates go down. You can’t do this with your cheapie modem and the plain vanilla MODEM7 described here. But for the average computer user, MODEM7 is a good communications program to start out with. After reading the instructions that follow, you needn’t be a micro whiz to use it. Also, you _may_ find that MODEM7 is as convenient as some commercial software for simple tasks, such as quickly checking your electronic mailboxes on The Source or CompuServe. Don’t forget: you shouldn’t pay a cent for the basic MODEM7 program itself except for the cost of a copied disk or another token fee. It’s public-domain software. So you can legally make copies for all your friends and business contacts who have modems and the same machine that you do. But how to track down your own copy? Through CP/M user groups, you can locate versions of MODEM7 set up for different computers and disk drives, or you might find an organization of IBM owners, Kaypro fanatics, or others. The better computer stores can steer you to the right people. Incidentally, if you distrust your store, you might not want to say exactly why you’re trying to catch up with a user group. Bear in mind that the computer store isn’t going to make a profit off a free program. Some organizations, however, are selling MODEM7 at next to nothing through the mail. For instance, the Public Domain Software Copying Company says it has versions for the IBM PC and clones, all the Kaypro machines, the Morrow micros and Osborne, among others. The cost as of late 1984 was $10. The address is 33 Gold St. cl3, New York, N.Y. 10038; the telephone number, (212) 732-2565. The company also offers separate programs that will adjust stop bits and other settings, eliminating the need for programming. These programs aren’t universal. Like MODEM7 itself, they might not work for your particular machine. The Public Domain Software Copying Company also says it offers a low-cost program for the Apple II that lets it communicate with computers using MODEM7. In addition, you might also investigate PC-TALK III, commonly available through IBM user groups. If they’re ethical, they’ll encourage you to send a small “donation” to PC-Talk’s originator, Andrew Fluegelman, who wanted to save distribution expenses through this “freeware” approach. You needn’t feel obligated to pay until you’ve tried the program. Probably, however, you’ll find PC-TALK to be worth the $35 or $45 it may cost; this software is more sophisticated than MODEM7, which I’m focusing on because of its simplicity. Another excellent MODEM7 alternative—_for experienced computer-users_—is MEX. CP/M versions are available free through users groups and work on many machines, including Kaypros; and NightOwl Software (telephone 800/648-3695 or NITEOWL) expects to sell it for $59.95 in an IBM version. Most of MEX’s send-and-receive commands overlap with MODEM7’s. MODEM7 as of 12/18/80 Originally Written by Ward Christensen Revisions by Mark M. Zeiger, Jim Mills WRT —Write file to disk (from terminal mode) DEL —Erase present file (from terminal mode) RET —Return to terminal mode with no loss of data XPR —Toggle expert mode (Menu on/off) DIR —List directory (may specify drive) CPM —Exit to CP/M S —Send CP/M file R —Receive CP/M file T —Terminal mode (optional file name) E —Terminal mode with echo DEFAULT DRIVE: Command: IBM PC owners, fear not! This Kaypro version of MODEM7 shows the same menu that the IBM version, dated Oct. 15, 1982, does. The only real difference is the IBM adaptation’s use of the =DOS= command instead of the =CPM= one to return to the computer’s operating system. Here now is a plain-English guide to MODEM7’s version of December 18, 1980, as adapted in 1982 for the Kaypro, IBM, and many other machines. TO GET READY MODEM7 has two basic modes for Teletype-like communications, “Terminal” and “Echo.” For both parties to see both ends of the conversation, one must be in “terminal” and the other in “echo” if they are communicating directly. Just the “terminal” person will be able to record on his or her disk. The one in echo mode can’t save the material electronically. Beginning, you should read your computer’s instructions for information on how many stop bits and data bits your machine normally runs with. And does it use odd, even, or no parity? You might also get this information from your dealer or users group. Don’t worry right now about knowing about the full meanings of the terms. Just find out what the settings are. MODEM7 doesn’t provide for changing the settings. If the person at the other end can’t adjust them, either, and if those for his machine are different from yours, you’re out of luck if you don’t know how to fix the program code. You two may have to reach each other through an electronic mail service that mediates between machines. Often, however, micros are set for 1 stop bit, 8 data bits, and no parity, an informal standard. And just about all decent commercial programs for communications let you alter these settings. So does PC-TALK III. In addition, even though MODEM7 itself won’t change its bit settings, your user group may have some free or low-cost programs that you can load up to do the trick—and then use MODEM7. There’s one other little worry. Are you and the other person sending at the same speed over the phone lines? The normal speed for cheap micro modems is 300 baud or about 30 characters per second; for the deluxe ones, 1,200 baud. Don’t worry right now about what a baud is. Just make sure you and the other person are both at the same speed. MODEM7 often is set at 300. Some versions may allow for changing the software to accommodate different baud rates, but the command may not work on your particular brand of machine. By the way, remember that you must consider the baud rate not only of the software but of the hardware. Simply adjusting your software to send at 1,200 baud won’t do the trick if your modem can reach only 300 baud. Remember, too, that MODEM7’s speed command won’t necessarily govern your modem’s transmission speed, just your software’s. You also want to find out how to operate your modem. Some use a physical switch to change from voice to data. Others—smart modems—use commands that you type out while your modem program is in the terminal mode. You can tell a smart modem to dial a number or answer the phone automatically. TO TRANSMIT AND RECEIVE WITHOUT SAVING ANYTHING ON YOUR DISK Just think of your computer and the other person’s as two Teletype machines connected. When hitting a key on either Teletype, you or the other person can make the two both print, right? Well, it’s the same with the computers. Here, however, the “print” is characters on your two screens. Ready?