TRS‑80.org


Model 4 emulation card: Fact or fiction?

After Radio Shack introduced their MS-DOS compatible Model 1000 series, there were persistent rumors about a Model 4 emulation card that was being developed. Such a board would have been an clever way to help migrate Model 4 customers to the newer MS-DOS computers. Some people were even told at their Radio Shack stores that a Model 4 emulator would be released soon. But it never happened and no type of TRS‑80 emulator was ever released by Radio Shack.

At the time, Radio Shack sold the Trackstar 128, an Apple IIc emulator card created by Diamond Computer Systems. The Trackstar used actual Apple II ROMs (licensed from Apple) along with custom hardware to achieve nearly 100% Apple compatibility. So the concept of a Model 4 emulation card certainly must have occurred to people at Radio Shack.

I’ve had three different people write to me (years apart) recalling details of a Model 4 emulation project that Radio Shack worked on but pulled at a very late stage. Their accounts match in almost all the details.

The Electric Crayon

Back in the late 1970’s, the Apple II and the TRS‑80 Model I were fierce competitors for computer sales. One advantage the Apple II had over the Model I was the ability to display color graphics. One of the first Model I productsto address this deficiency was the Percom Electric Crayon. Percom introduced the Electric Crayon in December 1979 for a base price of $249.00. It was featured on the cover of the January 1981 issue of 80 Microcomputing.

The Electric Crayon was a small (12 inch wide by 9 inch deep) box which output a composite video signal that could drive either a monitor or a television set. It connected directly to the TRS‑80 printer port and was controlled using EGOS, a ROM-based operating system. EGOS was directly programmed using single character commands. Virtually unique among TRS‑80 color add-ons, the Electric Crayon did not use the TMS9918 graphics chip and did not support sprites.

What does S-80 mean?

“S-80” was a non-trademarked synonym for for the trademark “TRS‑80.” It was usually used to refer to the TRS‑80 expansion bus (“S-80 bus”), but sometimes it was used as an all-encompassing term for the TRS‑80 and compatibles (“S-80 computers”). Other notable uses include the newsletters S-80 Bulletin (originally TRS‑80 Bulletin) and S-80 Computing (originally TRS‑80 Computing) and the magazine Softside: S-80 Edition.

One definition of the term appeared in the March/April 1980 issue of 80-U.S. Journal:

Mikeegraphic Graphic System

The Mikeegraphic Graphics System was a high-resolution graphics add-on for the TRS‑80 Model I and Model III. It was sold by Mikee Electronics Corporation for $340. Originally known as the Mikeeangelo when it was introduced in late 1981, the name was changed to Mikeegraphic just a few months later, presumably to avoid confusion with another product.

Unlike the 80-GRAFIX, which provided high-resolution using a programmable character generator, the Mikeegraphic used a true bitmapped graphics screen. The high-resolution screen was mapped in its entirety at the top of the TRS‑80 memory.

The Gamer’s Cafe

“The Gamer’s Cafe” was a column about TRS‑80 gaming which ran in 80 Micro magazine. It first appeared in the November 1982 issue near the height of the TRS‑80 game market and ran until April 1984. “The Gamer’s Cafe” had some similarities to “Captain 80,” a column written by Bob Liddil that premiered in the first issue of 80 Microcomputing in 1980 and later appeared in 80-U.S. Journal.

With only a few exceptions, “The Gamer’s Cafe” was written by the fictional character of Rodney Gambicus. The column started when Rodney and his friend Winthrop Luzerdraw decided to travel the country in a Ford Econoline van. They filled the van with TRS‑80 computers and games, including multiple Model I’s, Model III’s, Color Computers, and two Pocket Computers that the Radio Shack dealer threw in as part of the deal. They also had a PMC‑80 which they described as a “PMC ½.” Their plan was to stop at various locations around the country, put out tables, and let people play TRS‑80 games, literally a “Gamer’s Cafe.”