The company Radio Shack (also Tandy) produced two different home computer systems:
- TRS-80 with Z80 CPU, since 1977 (compatible with the Video Genie, line since 1981):
- Model I/III/4
- Model II/16/12
- TRS-80 Color Computer (also known as "CoCo") with MOS Technology 6809 CPU:
- CoCo 1: with lower RAM, since 1980 (compatible with the Dragon 32/64, since 1982).
- CoCo 2: the same design as model, also with more RAM (up to 64 KB) and compatible with OS-9, since 1983.
- CoCo 3: expanded graphics and a minimum of 128 KBRAM, since 1986.