Posts in the “Hardware” Category - page 3

The Omikron Mapper

The Omikron Mapper was the first (and probably most popular) CP/M hardware add-on for the TRS‑80 Model I and Model III. It allowed unmodified CP/M programs to run on a TRS‑80, something not normally possible. The Omikron Mapper was introduced in 1979 by Omikron Systems, a Berkeley, California company run by George Gardner.

Omikron Systems sold three versions of the Omikron Mapper from 1979 to 1984:

The original Omikron Mapper I was for the Model I.

The HUH Electronics Model 8100

After the Radio Shack TRS‑80 Model I was introduced in 1977, many companies were said to be developing an interface to allow the Model I to use the wide selection of S-100 hardware available at the time. HUH Electronics of San Mateo, California was one of the few companies (if not the only) to actually release a S-100 interface. Their Model 8100, introduced in November 1978, had six slots to allow up to six S-100 devices to be connected to the Model I.

The Expandabus

The TRS‑80 Model I, unlike some other contemporary computers, offered no way to install expansion cards internally. The Model I did have an expansion bus connector which allowed users to attach external hardware devices, such as the Radio Shack Expansion Interface. But the single connector meant that only one hardware device could be attached to a Model I at a time.

The Seatronics Super Speed-Up

The Seatronics Super Speed-Up was the fastest commercially available speed-up board for the TRS‑80 Model 4. It could double the Model 4 speed to 8 MHz, without requiring any performance sapping memory wait states. The Super Speed-Up was sold by Seatronics, a company based in Maastricht, Holland, for $129.00. (A review in 80 Micro identified Sylvester Technologies of Cypress, Texas as the United States distributor, but that appears to have been a mistake.

The Network 4

The Network 4 was a classroom networking system sold by Radio Shack that was popular in computer labs in the mid-1980’s. It allowed one computer used by a teacher to be connected to up to 63 student computers. The Network 4 was based around the TRS‑80 Model 4, well after MS-DOS computers became more common. It was probably one of the biggest reasons the TRS‑80 Model 4D remained in the Radio Shack catalog until 1990.

The Alpha Technology Super4

The Super4 was a popular speed-up board for the TRS‑80 Model 4. Introduced in 1984 by Alpha Technology, Inc. (not to be confused with Alpha Products), the Super4 was both inexpensive and easy to install. As the advertisements stated, it required “No trace cutting. No soldering. No wires to connect.”

The XLR8er

The XLR8er (pronounced accelerator) was a speed-up and memory expansion board for the TRS‑80 Model 4, regarded by many to be the ultimate Model 4 expansion. The XLR8er replaced the Model 4 Z80 CPU with an enhanced microprocessor that offered 256K of additional memory (for a total of 384K) and up to double the speed. The XLR8er originally sold for $299.95 (with memory) when H.I. Tech, Inc. introduced it around 1986, but that price soon dropped to $249.95.

The Anitek MegaMem

The MegaMem, introduced in early 1990 by Anitek Software Products, was the ultimate memory upgrade solution for the TRS‑80 Model III and 4. By using the same high capacity SIP (single in-line package) memory modules used in PC compatibles at the time, the MegaMem allowed a Model 4 to be upgraded as high as 8MB. Unlike the HyperMem, an earlier Anitek memory upgrade product, the MegaMem required no soldering, trace cutting, or other surgery to the computer.


Like many personal computers at the time, the TRS‑80 Model I had fairly primitive built-in sound capabilities. That changed in 1980 with the introduction of the Orchestra-80, a small $79.95 unit that plugged into the TRS‑80 and could play music with four simultaneous voices over a six octave range. Orchestra-80 was sold by Software Affair, Ltd., a company created by Bryan Eggers and Jon Bokelman. It became one of the best remembered hardware add-ons for the TRS‑80.

The TRS‑80 Multi-Pen Plotter

The TRS‑80 Multi-Pen Plotter (catalog number 26-1191) was similar to the earlier TRS‑80 Plotter/Printer (catalog number 26-1190), but offered one important new feature: the ability to print in color. Described as an “intelligent plotter,” the Multi-Pen Plotter used replaceable colored pens to print on paper or transparencies. Even at a price of $1995.00, the Multi-Pen Plotter was cheaper than many other color output alternatives available at the time.