Tandy 2000

The Tandy 2000 is a personal computer introduced by Radio Shack in September 1983 based on the 8 MHz Intel 80186 microprocessor running MS-DOS. By comparison, the IBM PC XT (introduced in March 1983) used the older 4.77 MHz Intel 8088 processor, and the IBM PC/AT (introduced in 1984) would later use the newer 6 MHz Intel 80286. Due to the 16-bit data bus and more efficient instruction decoding of the 80186, the Tandy 2000 ran significantly faster than other PC compatibles, and slightly faster than the PC AT. (Later IBM upgraded the 80286 in new PC AT models to 8 MHz, though with wait states.) The Tandy 2000 was the company's first computer built around an Intel x86 series microprocessor; previous models used the Zilog Z80 and Motorola 6809 CPUs. While touted as being compatible with the IBM XT, the Tandy 2000 was different enough that most existing PC software that was not purely text-oriented failed to work properly. The Tandy 2000 and its special version of MS-DOS supported up to 768 KB of RAM, significantly more than the 640 KB limit imposed by the IBM architecture. It used 80-track double-sided quad-density floppy drives of 720 KB capacity; the IBM standard at the time of the introduction of the Tandy 2000 was only 360 KB. The Tandy 2000 had both "Tandy" and "TRS-80" logos on its case, marking the start of the phaseout of the "TRS-80" brand. The introduction of IBM's Model 5150 Personal Computer in August 1981 created an entirely new market for microcomputers. Many hardware and software companies were founded specifically to exploit IBM's and Microsoft's new presence as a standard-setter for small computers, and most other established manufacturers shifted focus to it as well. By this date Tandy/Radio Shack had been in the small-computer market for four years, since its August 1977 introduction of the TRS-80 Model I. The new computer division followed in October 1979 with the TRS-80 Model II—a high-end business-oriented system. In 1983 the TRS-80 Model 4 succeeded the Model III (which itself had replaced the Model I) in the consumer and educational markets.