The Color-Graf

The Color-Graf was a color graphics interface for the TRS‑80 Model I and Model III. Sold by Solectronics, the Color-Graf originally cost $260 for the Model I version. That price was later reduced to $195 for the Model I version and $235 for the new Model III version. Solectronics advertised the Color-Graf from 1982 to 1983.

How popular were the TRS‑80 magazines?

80 Microcomputing, later 80 Micro, was the most popular of the TRS‑80 magazines. It was ranked the seventh fastest growing magazine in 1982 and was the third thickest magazine that year. (Those figures were for all magazines, not just computer magazines.)

80 Microcomputing began publishing in 1980, and its circulation rose steadily until it topped 124,000 readers in 1983. Circulation began a slow decline after that although subscriptions picked up slightly in 1985.

The Cassette Gazette

Back in 1983, Lemons Tech and KWIK Software advertised a one issue joint newsletter named the Cassette Gazette. The Cassette Gazette described the products sold by the two companies, mixed with operational advice and interesting facts about using cassettes with the TRS‑80. It appears to have been written by Wayne Lemons, the founder of Lemons Tech. I received my copy back in 1983, and it has always been a favorite of mine.

An Interview with Jack Crenshaw

Jack Crenshaw has a long history with computers, and one of his first microcomputers was a TRS‑80 Model I. Readers of 80 U.S. Journal might remember his comments about the Exatron Stringy Floppy. Others will remember his “Let’s Build a Compiler” tutorial series. His “Programmer’s Toolbox” column appears in Embedded Systems Design magazine, for which he is also a contributing editor.

This interview was conducted over January and February 2009.

The Next Step

“The Next Step” was a popular column written by Hardin Brothers that began in the February 1983 issue of 80 Micro. Originally conceived as a five part column about integrating BASIC and assembly language, “The Next Step” went on to become one of the longest running columns in the magazine.

The focus of “The Next Step” was programming the TRS‑80 in assembly language. It covered the Model I and Model III at first, but had largely switched to the Model 4 by 1984. The name was a reference to assembly language as being the next step beyond BASIC, as was stated in the first column:

An Interview with Paul Andreasen

Paul Andreasen was the primary designer of the Mikrokolor color graphics interface and his company, Andreasen’s Electronics Research & Development, sold versions for several TRS‑80 models (including the Model 100). In this interview, which was conducted over January and February 2009, he talks about his varied and interesting experiences.

Was the Model III created to replace the Model I?

The TRS‑80 Model III, introduced in August 1980, is often described as a replacement for the TRS‑80 Model I, introduced in August 1977. Considering that the Model I was discontinued just six months later due to its failure to meet new FCC regulations, it is easy to assume that the Model III was always intended to replace the Model I.

But Radio Shack showed no sign of any plans to discontinue the Model I after the introduction of the Model III. It remained in the catalog at a price $200 lower than the Model III. Jon Shirley, Vice President of the Computer Division at Radio Shack, wrote in his “View from the Seventh Floor” column in the September 1980 issue of the TRS‑80 Microcomputer News:

TRS‑80 Microcomputer News

The TRS‑80 Microcomputer News was Radio Shack’s own official publication supporting the TRS‑80, sent for free to anyone who bought a TRS‑80 computer. The motto described it as “The microcomputer newsletter published for TRS‑80 owners”.

Originally called the Radio Shack Microcomputer Newsletter, the first issue, published in 1977, was four pages long. It was published irregularly after that (two issues in 1978 and seven in 1979) until it changed to a monthly publication schedule with the October 1979 issue. It remained monthly from then on, with the exception of three combined issues in 1980 and 1982. The name changed to the TRS‑80 Microcomputer News with the March/April 1980 issue.

How to transfer files using FastTerm

One of the most common questions I receive is about how to transfer files from a Model 4 to another computer. Here is one of the simplest techniques I have found for a null-modem cable transfer.

You will need to use a null-modem cable to connect your Model 4 to another computer and run a communications program on both computers. Both communications programs need to be capable of performing YMODEM transfers. If your other computer is running Windows, then HyperTerminal (which was bundled with Windows XP and earlier) is a good choice.

In my opinion, the best communications program for the Model 4 was FastTerm, by Mel Patrick. For file transfers, the version that you need is FastTerm II version 4.62. That was the final version and the only one released as a full registered version that supported YMODEM batch transfers. You can download it here as a disk image or as a ZIP file.


ULTRADOS was the first TRS‑80 operating system written by Vernon Hester. Introduced in September 1980, ULTRADOS was sold by Level IV Products, a software and hardware retailer based in Michigan. The regular price for ULTRADOS was $119.95 but the introductory price of $89.95 lasted for several months. ULTRADOS was for the Model I only; there never was a Model III version.

Originally called Level IV DOS, ULTRADOS began life as a heavily patched version of Model I TRSDOS. However, Vernon Hester made so many modifications that ULTRADOS bore little resemblance to TRSDOS. ULTRADOS was a very stable operating system with the bugs of TRSDOS corrected.