The Tandy TRS 80 model 1 was the first member of one of the most famous computer family. It was one of the first home computer and was launched at the same time as famous computers like the Apple II or the Commodore PET. Beside, Tandy competitors nicknamed was “Trash-80”.
The TRS-80 was developed was developed within the Radio Shack engineering group, based upon several processor chips, SC/MP, PACE, 8008, 8080 and finally the Z80.
It used a black & white TV set, made by RCA, without tuner as monitor. The earlier models use a poor basic called Basic Level 1 (the Basic and the OS fit in the 4 KB ROM!). It was replaced later with the Basic Level 2 which needed a 12 KB ROM.
To offset its poor characteristics, Tandy developed a device called Expansion Interface which brings a lot of new features : additional 16 or 32kb RAM, two tape unit connectors, a printer port, a floppy disk controller, a serial port and a real time clock.
