10 Most Popular Computers in History

Tandy TRS-80
This is the TRS-80 Model 100, an extension of the original TRS-80 with a built-in liquid crystal display (LCD) screen. How's that for a tablet? SSPL via Getty Images

Ah, Radio Shack. Once upon a time, it sold computers under its very own brand. And they were hugely successful. In the 1970s, when cassette tapes, and not floppy disks, were the go-to storage medium for computers, Tandy put out a personal computer called the TRS-80. Thanks to the TRS-80, the Tandy name was as big as IBM or Apple or Commodore in the PC market of the 1980s.

The TRS-80 launched in 1977, before the home computer market had really exploded. Tandy offered its first model with 4K of RAM, a 1.77 MHz processor and a 12-inch monitor for $600. Later models and a $300 Expansion Interface greatly increased the computer's capabilities, adding floppy support, extra ports and more memory [source: Goldklang].

Tandy's TRS-DOS (disk operating system) was a popular OS predating MS-DOS. Microsoft's early operating system bore some similarities to TRS-DOS -- no surprise, since Tandy sold more than 200,000 units and followed the TRS-80's success with more popular systems such as the 1980 Color Computer, or CoCo [source: Old Computers].