The TRS-80 Micro Computer System (TRS-80, later renamed the Model I to distinguish it from successors) is a desktop microcomputer developed by American company Tandy Corporation and sold through their Radio Shack stores. Launched in 1977, it is one of the earliest mass-produced and mass-marketed retail home computers. [4] .

The TRS-80 (which became known as the Model I after the Model II was introduced in 1979) was created by Don French and Steve Leininger. It ran a Zilog Z80 at 1.77 MHz and came with 4K of RAM, and a 4K ROM of what was called Level I BASIC .

While some Tandy executives were skeptical about the success of the PC market, the availability of the TRS-80 on five thousand Radio Shack store shelves helped the Model 1 sell over one hundred thousand units during its first year, half of total PCs sales in 1978. The TRS-80 had its microprocessor inside its keyboard.

A TRS-80 Model 1 was the first microcomputer I ever saw. It started the infatuation with microcomputers generally. I've got two of these models. The first is an early Level 1 BASIC cassette-based unit, shown in the top photo.

The TRS-80 was the most expensive single item RadioShack had ever carried to that date, and RadioShack even required a $100.00 deposit to order the computer. Even so, they couldn't keep up with the demand, resulting in the units being backordered for several months.

On display at over 7000 Radio Shack Locations, TRS-80 Model I is a microcomputer you can see and try before you buy. It’s a proven system, used by business people, professionals, and “just plain folks” everywhere for accounting, education, lab work, budget management, word processing – even games at home.

TRS-80机是最早大规模生产和销售的家用电脑之一，采用Zilog Z80处理器（而不是当时更常见的Intel 8080），4 KB DRAM标准内存，配备全功能QWERTY键盘和用于程序存储的盒式磁带驱动器，体积小巧，具有文字处理和会计功能。

Model 1 Overview. The Model 1, in it's Level II BASIC configuration, consists of a Z-80 processor running at 1.77 MHz, 4 to 48K of RAM (32K of that being housed in the optional Expansion Interface), and 12K of ROM. The 16 line by 64 character video is …

The TRS-80 Model 1 was Radio Shack's first personal computer. It was developed back in the late 1970's when the only home computers available to the general public were things like the Altair kits, and (if I remember correctly) the first Apple machine.

By 1980, Radio Shack had released the new TRS-80 Model III. It is basically a super-Model I, with all of the Model I options built-in, including up to 48K RAM and two (optional) internal floppy drives. There was some controversy with this announcement, though.