Color Computer 1

Color Computer 1 (1980-1983)

Color Computer 1

TRS-80 Color Computer from 1980

The Radio Shack TRS-80 Color Computer was originally made available in 1980. A number of peripherals were available: tape cassette storage, serial printers, a 5.25 inch floppy disk drive, a pen and graphics tablet called the "X-Pad", speech and sound generators, and joysticks.

4K (26-3001), 16K (26-3002, 26-3004, 26-3004A), or 32K (26-3003)

Versions with at least 16K of memory installed shipped with standard Microsoft Color Basic or (optionally) Extended Color Basic. It used a regular TV for display, and TV-out was the only available connection to a display device.

The early versions of the CoCo 1 had a black keyboard surround, the TRS-80 nameplate above the keyboard to the left side, and a RAM badge ("button") affixed on the top and right side of the case. Later versions removed the black keyboard surround and RAM button, and moved the TRS-80 nameplate to the mid-line of the case.

Model 26-3004 has been found in both PAL and NTSC configurations, 26-3004A being distributed in Canada.

Initial versions of the CoCo were upgraded to 32K by means of piggybacking two banks of 16K memory chips and adding a few jumper wires. A later motherboard revision removed the 4K RAM option and were upgraded to 32K with "half-bad" 64K memory chips as a cost-cutting measure. These boards have jumpers marked HIGH/LOW to determine which half of the memory chip was good. This was transparent to the BASIC programmer since in either configuration 32K of memory was available.

As memory production yields improved and costs went down, many (perhaps most) 32K CoCo 1s were shipped with perfectly good 64K memory chips; many utilities and programs began to take advantage of the "hidden" 32K.

Eventually the 32K memory option was dropped entirely and only 16K or 64K versions were offered. All versions that shipped with standard Color BASIC could be upgraded to Extended BASIC by simply plugging a ROM into an empty socket provided on the motherboard.

64K (26-3003B) White case CoCo 1 and TDP 100

Toward the end of the CoCo 1 production run, some models shipped in a white case with a modified keyboard, often referred to as the "melted" keyboard, which had bigger keycaps but a similar rubbery feel. At about the same time, another white-cased "CoCo", the TDP-100, was marketed through Tandy Data Products (TDP) and sold through a different distribution channel. Except for the nameplate and case, the TDP-100 was completely identical to the CoCo 1. The TDP-100 had ventilation slots that ran the entire length of the case, rather than only on the sides. This ventilation scheme was carried over to the CoCo 2.

Tandy Data Products TDP-100 (64K badge was added by user)

References

• TRS-80 Color Computer @ Wikipedia
• Color Computer 1 @ TandyCoCo.com