Classic Computer Magazine Archive ANTIC VOL. 3, NO. 3 / JULY 1984


The world of shortwave radio & computer communications


How does taking a crack at decoding secret CLA or KGB messages appeal to you? Or perhaps -- less exciting, but safer -- receiving bulletins from news services around the world?

You can do both, and more, with radio communications. By hooking up your Atari to a short-wave or ham-radio receiver, you can become part of an exciting way of communicating with the outside world. You can, in fact, accomplish just what you could with a telephone and modem, but without making payments to Ma Bell, her offspring or her clones!

The first thing you need to get started is a good short-wave or ham-radio receiver. Good doesn't necessarily mean expensive, although some can cost several thousand dollars. The new- digitally-controlled, short-wave radios offer high quality performance: They are sensitive, relatively inexpensive, and have stable receivers. Even better, anyone who can turn on a stereo can use one.

Next, get an antenna. This can be as simple as a piece of wire running along a wall or as complex as the equipment at a military installation.

A radio modem, also known as a Terminal Unit (TU), converts the signals from your radio's speakers into pulses that feed into your Atari personal computer (PC). (See the review of Macrotronics' RM-1000 Radio Modem in this issue.) Ham radio operators have developed many programs that will work with your Atari if you use the RS-232 port of an Atari 850 or similar interface to connect your computer and a radio modem. Some of these programs even allow you to set up an on-the-air bulletin board, provided that you have a license to transmit.

The Federal Communications Commission (FCC) set up the Amateur Radio Service so that amateur radio users could apply and test for a license to transmit voice, code and digital communications over the radio waves. Specific privileges vary with the type of license granted. But once you acquire a license to transmit, a new neighborhood opens up to you -- the entire planet! Amateur radio even has its own series of satellites for use by the world-wide community of "hams."

Without a license, however, you are not allowed to transmit messages, or to make digital or code transmissions on Citizens Band radio.

Even if you can't transmit your own messages, you can garner a tremendous amount of information just by listening --- in fact, that's how I became a ham radio operator. Once you gain access to the airwaves, however, you can retrieve even more information. You can "hear" (via the words that appear on your monitor) radio operators chatting about equipment and see the pictures they transmit (these can then be printed on your printer). You also can receive news bulletins from the far ends of the Earth that you'll never see in your local newspaper. And, yes, covert and overt agents all over the world do send coded secrets to other agents and to their superiors. Test your programming skill by trying to decode these secret messages. Who knows -- you may have a future with the CIA. . . .


There are several useful modes of radio communication, including Morse Code, radioteletype, and ASCII. With a radio modem and accompanying software, you can choose the mode in which you want to receive and transmit messages. Type in your message, and the software does the rest. Differences exist among these modes, however, and the government places some limitations on their use. Let's take a look at each of them:

-- Morse Code -- One of the first "digital" codes, this internationally accepted code consists of a series of long and short beeps that form each letter of the alphabet. Invented long before computers, Morse Code presents some problems when used with them, because the varying length of each character makes software design difficult. As a result, most of the Morse Code now being sent is sent by hand, not machine. The software used in this application must be able to analyze human-caused Variations in the code to translate it properly and this causes problems. Radio operators call this mode CW for continuous wave.

-- Radioteletype -- This mode of communication uses a five-bit code with a unique feature: most of its characters have two meanings. A control code is used to toggle between the two character sets. This code was developed for use with electro-mechanical "Tele-type" machines, and is currently the most commonly used non-telephone mode of computer communication. Radio operators have nicknamed it RTTY (pronounced Ritty).

-- ASCII -- The "native son" of intercomputer communications, ASCII was recently approved for radio communications by non-commercial and non-governmental services. This mode allows an extensive set of characters to be sent, some of which can be nonstandard. This can be quite useful to Atari PC users because of the Atari's special control and graphics characters. ASCII is slowly becoming more popular as a communications mode for radio operators, but it will take time for its popularity to become widespread. Many organizations and amateurs are diehard RTTY users.

The following list of organizations and manufacturers may help you get started in the world of radio communications. By the way, the Atari Microcomputer Network, a users' group with more than 800 members, meets on an almost weekly basis, and the participants don't even have to leave the comfort of their homes. We communicate by radio, of course!

-- Universal Amateur Radio
4555 Groves Road, Suite 3
Columbus, OH 43227

This group publishes a comprehensive list of radioteletype stations that includes the times and frequencies for each service.

-- American Radio Relay League
225 Main St.
Newington, CT 06111

A national organization of amateur radio operators, ARRL publishes QST, a general information magazine, and dozens of specialized books on digital and code communications.

-- The Atari Microcomputer Network Amateur Radio Operators Users' Group
4749 S.R. 207 N.E.
Washington C.H., OH 43160
(614) 869-3597

An on-the-air users' group of amateur radio operators and short-wave listeners, the Atari Microcomputer Network publishes Ad Astra ... , a journal composed of member-written hardware articles and programs.

-- Trio-Kenwood Communications
1111 West Walnut
Compton CA 90220

A manufacturer of amateur and short-wave radio equipment.

-- Macrotronics, Inc.
1125 N. Golden State Blvd., Suite G
Turlock, CA 95380
(203) 667-2888

A manufacturer of hardware and software that allows Atari computers to be operated as RTTY, ASCII or CW terminals.

-- Yaesu Electronics Corp.
6851 Walthall Way
Paramount, CA 90723
(213) 633-4007

A manufacturer of amateur and short-wave radio equipment.

Jack McKirgan II (WD8BNG) is the national net coordinator for the Atari Microcomputer Network.