Android Nim

Android Nim was Leo Christopherson’s first game for the TRS‑80. It was featured on the cover of 80-Northwest Journal (later 80-U.S. Journal) in November 1978 and was released by 80-NW Publishing (later 80-U.S. Software). The cost was $8.00 for cassette and $13.00 for disk, with a $2.00 discount for 80-Northwest Journal subscribers. The game helped to popularize the magazine, and 80-U.S. Journal used an android for its mascot until 1981.

Soon after the original release, Leo Christopherson enhanced Android Nim with sound and more animation, developing the techniques known as “string-packing” and “line-packing” in the process. The enhanced version of Android Nim cost $14.95. Like all of Leo Christopherson’s TRS–80 games, Android Nim was written in combination of BASIC and machine language.

More About BASIC Over Shortwave

I recently wrote about a September 1981 Radio Netherlands experiment to broadcast BASIC programs over shortwave. The concept of broadcasting BASIC programs over radio wasn’t new to Holland. The Hobbyscoop program, which aired on NOS (a Dutch domestic broadcaster), regularly broadcast BASIC programs over mediumwave (more commonly called AM in the United States). But this was the first time such a broadcast was attempted on shortwave.

The experiment was conducted as part of the Media Network program, which aired Thursdays on Radio Netherlands. As a long-time listener to Media Network (although not at that time), I was curious about the experiment and the results. Jonathan Marks, the host and producer of Media Network, was kind enough to provide me with more details about the test.

An Interview with Jim Stutsman

I recently had the opportunity to interview Jim Stutsman, whose works include MICRODOS and DBLDOS for Percom and Monte’s Windows for Montezuma Micro. In the interview, conducted in October 2008, he had some very interesting answers to my questions and provided some fascinating insight into the early days of the TRS‑80.


Arcnet, which stands for Attached Resource Computer NETwork, is a networking standard created by Datapoint Communications in 1976. It provided a way for multiple computers to share printers and files. One of the main advantage of Arcnet at the time was that it was substantially cheaper than its competitors, such as Ethernet.

Radio Shack sold Arcnet cards and hardware for the Model II/12/16/6000 series starting in 1982. Arcnet cards were planned for the Model III and 4 but were never released. Two remnants of that planned support are the four functions labeled “Reserved for Arcnet” in the Programmer’s Guide to TRSDOS 6 and an Arcnet boot error message in the Model 4P ROM.

The Langley-St. Clair Soft-View Replacement CRT

One frequent criticism of the TRS‑80 (especially the Model I) was the quality of the screen. Many complained of eyestrain and headaches after staring at the screen for a long time. Another frequent complaint was noticeable flicker, especially under poor lighting conditions.

One popular solution was the Soft-View replacement CRTs from Langley-St. Clair Instrumentation Systems, available for the Model I, Model III, Model 4, and Model 16. Their replacement CRTs used a slower-phosphor tube that was much easier on the eyes and virtually eliminated flicker. Here’s a quote from one of their advertisements:


MICRODOS, later known as OS-80, was the only TRS‑80 disk operating system that made no attempt at TRSDOS compatibility. It was written by James W. Stutsman and released by Percom in 1979. Rather than using a command shell like Model I TRSDOS, MICRODOS used extensions to BASIC. It implemented most of the Disk BASIC commands added by TRSDOS. Also unlike the other operating systems, MICRODOS had no file system. All disk accesses were made using the starting sector and length. As stated in the manual:

BASIC Programs Over Shortwave

I ran across an interesting news article by Chris Brown in the July 1981 issue of 80 Microcomputing, titled “Dutch to Air BASIC Program.” From the article:

In what may be a first, an international shortwave broadcasting station will soon broadcast a machine readable computer program around the world.

On Sep. 10, the Dutch World Radio Service, Hilversum, Holland, intends to broadcast a brief BASIC program in computer ready, CLOADable form as part of a weekly science segment called “Media Network”. The show features microcomputers as its topic, and the BASIC program broadcast will be a housekeeping program. It will be broadcast in TRS‑80, Apple and Pet compatible formats.

The broadcast may herald a new era in information exchange for microcomputerists. Should the reception of computer programs over the shortwave bands by listeners equipped with ordinary receivers turn out to be a straightforward process, the dissemination of software for popular microcomputers could take a large leap forward.

TRSDOS 2.3 Decoded and Other Mysteries

TRSDOS 2.3 Decoded and Other Mysteries was written by James Lee Farvour and published by IJG in 1982. It was volume six in the TRS‑80 Information Series.

In a way, this book was a companion to James Lee Farvour’s earlier Microsoft Basic Decoded and Other Mysteries. That book analyzed TRS‑80 Model I BASIC in great detail, describing how each part of the language worked. At the end of the book, it included the commented portion of a disassembly of the BASIC. It did not include the complete disassembly because Microsoft never gave permission for that to be published.

The Newclock-80

The Newclock-80 was a clock/calendar add-on for the TRS‑80 released by Alpha Products in 1983. It replaced their TIMEDATE 80 clock/calendar but remained software compatible with it.

The Newclock-80 plugged into the expansion bus and required no hardware modifications. The price was $59.95 for both the Model I and Model III versions, a significant reduction from the $95 price of the TIMEDATE 80. The Model III version also worked on the Model 4. In 1985, the price of the Model I version was reduced to $39.95.

The MicroMerlin

The MicroMerlin (referred to in some advertisements as the µMerlin) was a MS-DOS compatible add-on for the TRS‑80. It was released by Micro Projects Engineering in 1982 with a starting price of $1195.

The MicroMerlin connected to the expansion bus of a computer and required no hardware modifications to the computer itself. It originally supported the Model I and Model III, but later also the Model 4 and LNW. There were two hardware requirements: