TRS-80

The TRS-80 Micro Computer System (TRS-80, colloquially known as the "Trash-80", later renamed the TRS-80 Model I to distinguish it from its 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. The name is derived from Tandy Radio Shack Z80, referring to its Zilog Z80 8-bit microprocessor.
The TRS-80 has a full-stroke QWERTY keyboard, 4 KB DRAM standard memory, small size and desk area, floating-point Level I BASIC language interpreter in ROM, 64-character-per-line video monitor, and had a starting price of US$600 (equivalent to US$3,100 in 2024). A cassette tape drive for program storage was included in the original package. While the software environment was stable, the cassette load/save process combined with keyboard bounce issues and a troublesome Expansion Interface contributed to the Model I's reputation as not well-suited for serious use. Initially (until 1981), it lacked support for lowercase characters which may have hampered business adoption. An extensive line of upgrades and peripherals for the TRS-80 were developed and marketed by Tandy/Radio Shack. The basic system can be expanded with up to 48 KB of RAM, and up to four floppy disk drives and/or hard disk drives. Tandy/Radio Shack provided full-service support including upgrade, repair, and training services in their thousands of stores worldwide.
By 1979, the TRS-80 had the largest selection of software in the microcomputer market. Until 1982, the TRS-80 was the bestselling PC line, outselling the Apple II by a factor of five according to one analysis. The broadly compatible TRS-80 Model III was released in the middle of 1980. The Model I was discontinued shortly thereafter, primarily due to stricter US FCC regulations on radio-frequency interference. In April 1983, the Model III was succeeded by the compatible TRS-80 Model...