What Does TRS-80 Mean?
TRS-80 is a desktop microcomputer that was the first mass-produced personal computer systems. Launched in 1977, the name was an abbreviation of the name of the company making it and the microprocessor used inside, Tandy Radio Shack, and the Zilog Z80. They dominated the market as the bestselling PC until the mid-1980s and were rivaled by Apple II series. The TRS-80 series consisted of three models: Model I, Model III and Model 4.
Techopedia Explains TRS-80
The idea of a preassembled microcomputer was a new concept in the mid-1970s. Tandy Corporation's Radio Shack division, the manufacturer of the TRS-80 and owner of a large chain of electronic stores, initially thought of developing a kit that would help the users build a microcomputer from the scratch, but later the idea was rejected and TRS-80s were sold as a preassembled personal computer, saving users the trouble of soldering. Due to the fact that one could buy this computer and use it immediately, without having to first assemble it, the TRS-80 became known as an "appliance computer."
The Model I was essentially a mainboard and keyboard as a single unit, which was a common design in the 1970s 8-bit microprocessor era. With 4 KB of RAM (and later models had 16 KB RAM), the Model I had a separate power unit and it used a Zilog Z80 processor clocked at 1.77 MHz.