TRS-80 Color Computer - Prototypes and Rare Versions

Prototypes and Rare Versions

Various prototypes for the CoCo have surfaced over the years. In the 1980s, Radio Shack stores were selling a keyboard that would plug directly into a CoCo 2, though not labeled as such. This keyboard was part of a production run for the never produced Deluxe Color Computer. The Deluxe CoCo was referenced in CoCo manual sets and specifically mentioned as having extra keys, lowercase video, and the ability to accept commands in lowercase. Later versions of the CoCo 2, labeled Tandy instead of TRS-80, had the ability to display true lowercase, but did not accept lowercase commands, although this capability was later available through A-DOS, a third-party replacement ROM for the Disk Controller.

Production model CoCo 3s have been found with different circuit board layouts and socketed chips. In 2005, a rare CoCo 3 prototype surfaced at the Chicago CoCoFEST, with a built-in floppy disk drive controller and other items still not identified. It also did not use a GIME chip. Instead, all the functionality of the GIME was created using separate chips. There is a hobbyist effort to try to reverse engineer these chips so a modern GIME can finally be produced.

There is also a prototype Ethernet interface for the Color Computer, displaying a board layout date of 1984, and a few other mystery boards that have yet to be examined. There is some evidence that Tandy killed the Ethernet interface at the last minute: an ad mentioning the networking options for some of Tandy's Z80-based computers claimed that the Color Computer would soon have networking capabilities, and the printed manual for an upgraded version of OS-9 Level One listed networking in the table of contents, but had no corresponding text in the body of the manual.