The Radio Shack TRS-80 Model 1, introduced in 1977, was one of the first microcomputers to be distributed through a large chain of retail stores. The Model 1 (which gained the "Model 1" designation when the Model 2 was released later) is based on the Zilog Z80 microprocessor. The system board is enclosed in the keyboard portion of the unit. A monochrome display (which is based on an RCA black-and-white TV chassis) was included with the system.
Two different versions of BASIC were available with the Model 1: Level I basic, which is a 4K integer BASIC variant, and Level II basic, which is a variant of Microsoft Extended BASIC.
Peripherals can be added to the Model 1 by using an expansion interface, pictured beneath the monitor in the image above. The expansion interface connects to the system unit's expansion bus through a ribbon cable.
The expansion interface pictured above contains a controller for floppy disk drives (which are not pictured). Several different operating systems are available for disk-based TRS-80 systems, including TRS-DOS from Radio Shack/Tandy and LDOS.
Other TRS-80 computers in the collection
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