The TRS-80 was a series of models sold by Tandy through Radio Shack stores in the 70s and 80s. Announced in August of 1977, it was intended to compete with the Commodore PET and the Apple II. The original production was limited to 3,000 machines, just in case the market didn’t do well. Exceeding expectations, they sold 10,000 the first month. By the time it was discontinued in January 1981, 250,000 units of the Model I had been sold.
TRS-80 machines were all powered by the Zilog Z-80 microprocessor. They supported up to four floppy drives, and hard disks were available (though expensive) for them as well. While it’s true that the original machine, the Model 1, was a little flaky and probably deserved the nickname “Trash-80” at times, the rest of the product line was pretty solid. And even the Model 1 could be “fixed”. The basic system sold with 4k of RAM, which was increased to 16k in later systems but was exapandable to 48k. Thier most familiar feature was the cassette drive on which data was stored. It orginally shipped with a black on white display, but later models were produced with color. It also included two versions of BASIC. The Model II came later and was aimed at business, with an 8″ floppy and 64k of memory.
Priced at $599, the TRS-80 was the most expensive single item Radio Shack had ever sold. They had originally intended to use it in the chain’s stores if it didn’t do well.
Mashable has a fascinating look at a 1981 Radio Shack catalog, naturally packed with all things TRS-80; http://mashable.com/2015/02/06/radio-shack-catalog-1981/