I have two main units, power adapter, Tandy Radio Shack Video Display,
Tandy Radio Shack TRS-80 expandion interface, Realistic CTR-80
Cassette Recorder and Tandy Radio Shack joystick.
type computer
country USA
year 1977
os TRS DOS, built in Basic Level 1
cpu Zilog Z70
speed 1.77 MHz
ram 4 KB
rom 4 KB
graphic 128×48
colors mono
sound none
ports monitor, cassette, expansion port
The TRS-80 Model I — One of the Trinity
Released in August 1977, the Radio Shack TRS-80 Model I was one of the three computers that launched the personal computer industry — the ”1977 Trinity” alongside the Apple II and Commodore PET. Sold through Tandy’s 3,000+ Radio Shack stores at $599, it was the most accessible of the three: you could walk into a shopping mall, buy a TRS-80, and walk out with a complete computer. In its first year, Radio Shack sold 100,000 units — more than the combined sales of all other personal computers at the time — making it briefly the best-selling personal computer in the world.
The 1977 Trinity
The simultaneous arrival of the TRS-80, Apple II, and Commodore PET in 1977 transformed personal computing from a hobbyist kit-building activity into a consumer product category. Each machine offered a complete, working computer rather than a kit to assemble, and each targeted a different market segment. The TRS-80’s strength was its retail distribution — Radio Shack’s stores were ubiquitous in American shopping centres, giving the TRS-80 unprecedented consumer visibility. For millions of Americans, the Radio Shack store was their first encounter with a personal computer.
Z80 and BASIC
The TRS-80 Model I used a Zilog Z80 processor at 1.77 MHz with 4 KB of RAM (expandable to 48 KB) and 4 KB of ROM containing Level I BASIC. An upgraded Level II BASIC — written by Microsoft — improved compatibility and capability significantly. The machine’s monochrome 64×16 character display and cassette storage were primitive by later standards, but represented a practical computing package that introduced programming and computing to a generation of American students and hobbyists.