The TRS-80 Color Computer

written by Matthew Reed

The Color Computer 1

The Color Computer from a Radio Shack catalog

The TRS-80 Color Computer, commonly nicknamed the CoCo1, was the first in Radio Shack’s line of inexpensive home computers. Introduced on July 31, 1980 (the same day as the TRS-80 Model III and the TRS-80 Pocket Computer), the Color Computer was also known as the Colour Computer outside of the United States, and later as the Color Computer 1.

The Color Computer was part of Radio Shack’s attempt to diversify their computer product line.2 Costing only $399.00 for its basic model, it was designed to compete with other lower-cost computers, such as the Atari 400 and the Commodore VIC-20. But the Color Computer inspired a wide range of uses, multiple support magazines, and a vibrant third-party software and hardware market. The Color Computer series was probably the best selling of Radio Shack’s own computer models.3

Here is how Radio Shack introduced the Color Computer in their catalog:

The all-new TRS-80 Color Computer features vivid color graphics, instant-load Program Paks, expandability and sound at a low price you won’t believe. Since it attaches to any color television set, it can easily be used anywhere for home, personal, or educational uses. Easy-to-use Program Paks program your Color Computer instantly for a variety of games and personal uses. Just pop one into the computer, and you’re ready to go!


Like the Model II introduced the previous year, the Color Computer wasn’t compatible with existing Model I software.4 Unlike the Model I and Model II, which both used the Zilog Z80 as a microprocessor, the Color Computer used the Motorola 6809. (Early rumors said it would be called the TRS-90 because it lacked a Z80.) This was unusual because most other inexpensive computers at the time (and some expensive ones such as the Apple II) used the MOS Technology 6502. The Motorola 6809 was a highly regarded processor with many design features that were more in line with a 16-bit microprocessor. Even though the 6809 in the Color Computer ran at only 0.895 MHz, the design meant that it was comparable to the 2.03 MHz Z80 in the Model III.

Color Computer catalog image

Another view of the Color Computer from a Radio Shack catalog


The Color Computer had good specifications for a home computer at the time:

  • a Motorola 6809E processor running at 0.895 MHz
  • a 53-key “chiclet” keyboard, with arrows, BREAK, and CLEAR keys
  • uppercase-only text mode with 32 column by 16 lines
  • eight graphics modes, including 64 by 32 with eight colors and 256 by 192 with four colors
  • one RS-232 port (the so-called bitbanger port)
  • sound output with a 6-bit digital-to-analog converter
  • 1500-baud cassette I/O for storage
  • a slot for plugging in cartridges known as “Program Paks”

Like all previous TRS-80 models, the Color Computer came in a Battleship Grey colored case. The Color Computer shared much of its design, including the case, with the TRS-80 Videotex Terminal introduced earlier that year.5

Unlike the Model I and III, the Color Computer keyboard used what were known as “chiclet” keys. These were rubber keys, similar to those used on some calculators. The Color Computer was far from the only computer to use chiclet keys (even the IBM PCjr used them), although their use was controversial. Some people even preferred them to the more common full-travel keyboards.


For storage, the Color Computer used a 1500-baud cassette interface like the Model III, although the two formats were incompatible. Practically any cassette recorder could be used, but Radio Shack sold the CTR-80A cassette recorder (catalog number 26-1206) for $59.95.

In later 1981, Radio Shack introduced a Color Computer floppy disk interface (catalog number 26-3022) for $599.00. The interface came with a Disk Color BASIC Program Pak because, unlike the Model I and Model III, the Color Computer didn’t use a separate floppy operating system. The floppy disk was controlled through commands in Disk BASIC. Radio Shack also sold an additional floppy drive (catalog number 26-3023) for $399.00.

Other options included the oddly named $399.00 TRS-80 Color Video Receiver (catalog number 26-3010), a 13-inch color television set with Color Computer styling, intended for use as a Color Computer monitor. For use with games, Radio Shack sold a set of two joysticks (catalog number 26-3008) for $24.95.

The Color Computer 1

Another view of the Color Computer from a Radio Shack catalog


The original Radio Shack catalog listed two configurations for the Color Computer:

  • 4K Color Computer (catalog number 26-3001) for $399.00.
  • 16K Color Computer with Extended BASIC (catalog number 26-3002) for $599.00

The catalog described the BASIC in the 4K Color Computer as “stronger than the TRS-80 Level I and compares favorably to Level II, plus it has several commands that are unique.” It described the Extended Color BASIC as having “all the features of standard Color BASIC, plus advanced graphics capabilities.” It also allowed users to “generate complex sounds using more than one musical note.” Other features of Extended Color BASIC included “program editing capabilities, specific error messages, user-definable keys, string arrays up to 255 characters, floating point decimal, and machine language routines.”

For those who wanted to upgrade a 4K Color Computer later, Radio Shack sold a 16K Memory Conversion Add-on (catalog number 26-3015) for $119.00 and Extended BASIC (which required 16K) for $99.00

In their 1982 catalog, Radio Shack added the 32K Extended BASIC Color Computer (catalog number 26-3003) for $749.00. They also added a 32K RAM Kit (catalog number 26-3017) for $149.00. In the 1983 catalog, the 16K Color Computer became the default model costing $399.95.

Radio Shack offered the Color Computer in a number of different bundled configurations, from the “Home Entertainment and Control System” for $702.80 all the way to the “32K 2-Disk Professional Color System” for $2550.95.


There was very little software available for the Color Computer in its first year. There were only nine Program Paks listed in the first catalog, including Quasar Commander (catalog number 26-3051), Football (catalog number 26-3053), Chess (catalog number 26-3050), and Bingo Math (catalog number 26-3150). The pace of Radio Shack’s software development picked up afterward, as did the pace of third-party software development. Radio Shack later sold such well-remembered games such as Clowns and Balloons (catalog number 26-3087) and Dungeons of Daggorath (catalog number 26-3093).

There were very few “official” Color Computer versions of popular arcade games, but there were many highly regarded “unofficial” ports. Just a few of these included Donkey King by Tom Mix Software, Color Caterpillar by Soft Sector Marketing, and Sailor Man also by Tom Mix Software.

Radio Shack also sold educational software from Disney, such as Telling Time With Donald (catalog number 26-2530) and Problem Solving With Scrooge McDuck (catalog number 26-2531). They had an exclusive deal with Children’s Television Workshop for their educational software, including Big Bird’s Special Delivery (catalog number 26-2525) and Ernie’s Magic Shapes (catalog number 26-2524).

In addition to games and educational software, Radio Shack sold productivity software for the Color Computer in Program Pak, cassette, and disk versions. Some of the titles included the database Color File (catalog number 26-3103), the spreadsheet Spectaculator (catalog number 26-3104), and the word processor Color Scripsit (catalog number 26-3105).

The 64K Color Computer

The 64K Color Computer from a Radio Shack catalog

The Color Computer 2

Radio Shack announced the successor to the Color Computer, the Color Computer 2 on September 9, 1983. The original Color Computer (now often referred to as the Color Computer 1), made its last appearance in the 1984 Radio Shack catalog. This 64K version came in an “attractive white case with typewriter-quality keyboard” for $399.95.

  1. Dave Lagerquist is generally credited with coining the name CoCo in the October 1982 issue of Chromasette magazine. It’s odd that his offhand mention of CoCo as his nickname for his Color Computer caught on so universally. However, his other nicknames, such as Puck for his Model II, never did. ↩︎

  2. This eventually worked out into the rough divisions of home computers (Color Computer 1/2/3), personal computers (Model I/III/4), and business computers (Model II/12/16). However, Radio Shack itself sold both the Color Computer and Model I/III/4 for business applications. In later years, a fully equipped Color Computer 3 was arguably more powerful than a Model 4. ↩︎

  3. This is impossible to say for certain, because Radio Shack never released sales figures for their computers. But I think it is safe to say that the Color Computer 1/2/3 series sold the most units of any series (other for Tandy’s MS-DOS computers). ↩︎

  4. A surprising number of rumors claimed that the Color Computer would completely replace the Model I. This is hard to understand, because abandoning the substantial library of Model I compatible software would have made no sense for Radio Shack. ↩︎

  5. It is sometimes stated that the Color Computer replaced the Videotex Terminal, but they were actually sold at the same time. ↩︎

Categories: Computers


Bob says:

Thanks for the trip down memory lane! A 16K Extended Basic Color Computer that I bought in January or February of 1981 was my first computer (and I still have it). I have bought and built many other computers of vastly advanced technology over the years, but never quite matched the fun and discovery of learning to program, play games, explore online (via 300-baud dial-up BBSes and CompuServe), learn to use OS-9 (yes, THAT OS-9) … The Motorola 6809 CPU was an amazingly capable chip for its time. I could go on, but one more thing: in almost 37 years of consuming and programming computers, I have not yet run across ANY documentation from any hardware or software manufacturer – or book publisher, for that matter – that was as concise and easily understood as the books that Radio Shack provided with that machine. It took me from zero to understanding the use of virtually the entire BASIC language in a few days. Amazing.

Greg Robertson says:

I remember strapping by Coco on the back of my bike and taking to a radio shack warehouse to get the extended basic upgrade and memory. Thought I was in heaven.