Classic Computer Magazine Archive COMPUTE! ISSUE 1 / FALL 1979 / PAGE 30


DC Hayes Micro Modem $395.00

Michael Tulloch
103 White Cr.
Niceville, Fla. 32578

10 Perimeter Park Drive
Atlanta, GA 30341

I've been using a D.C. Hayes MicroModem for several months now. If you've ever used a time-share terminal you'll only know about half of what to expect. For those of you who've never time-shared, getting into the world of mainframes is a logical expansion of hobby computing. Owning a modem opens another field too, that of written communication. In addition to being able to access big machines you can type to your friends, interact with telephone bulletin boards and play interactive games.

The DC Hayes MicroModem consists of two parts. One is a PC board which plugs into the Apple (they recommend slot 3). It contains software in ROM to turn your Apple into a dumb terminal. You can even dial from the keyboard.

The other part is a small plexiglass and metal box apparently containing the telephone interface. Since this is an FCC registered device, you just plug it into your phone line. Then call the phone company, tell them you have an FCC registered device, give them the device number and ringer equivalent. There is no extra change in most cases.

Documentation of this device is excellent. Operating theory, sample programs, good instructions and even a history of modem technology is included. One of the sample programs allows you to call up your Apple (from work?) using a dumb terminal and write programs. This sure is a better way to spend lunch than playing cards! When you get home the program will be ready for you.

Computer to computer links are also possible. Our Tektronix 4051 has a program dump routine which can pass a whole program over its modem. We called my Apple at home and dumped a Tektronix BASIC program to it. The Tektronix displays each line as it is passed. Much to our surprise there appeared rather strange symbols and extraneous letters intermixed on the screen. We finally figured out that the Apple wouldn't accept some of the Tektronix graphic commands and was passing *** SYNTAX ERROR *** back to the 4051. The 4051 was interleaving this on its display. However, when I got home, all Apple syntax compatable lines were loaded in the Apple. The program even ran correctly except, of course, there was no graphic output.

Another nice feature is that there is nothing to assemble. It's just plug in and go. Programs can easily be written which do some very complex things over the telephone. One example Hayes gives is a message relay. You call the Apple and leave a message. The Apple then calls another computer or terminal and relays the message. It keeps trying until it gets through. All aspects of the modem operation are accessible to the programmer so transmission characteristics, number of rings to answer, and so on can be programmed.

At $395.00 the D.C. Hayes modem is a good buy. With all the telephone accessible hobbyists, computer stores, main frames, and club machines on line, you can quickly spend twice the purchase price on long distance telephone calls.