Tandy 2000

The Tandy 2000 is a personal computer introduced by Radio Shack on November 28, 1983, at COMDEX/Fall'83. It was the company's first computer built around an Intel x86 series microprocessor; previous computers from Radio Shack used the Zilog Z80 and Motorola 6809 CPUs. The Tandy 2000 was based on the 8 MHz Intel 80186 microprocessor, and could run MS-DOS. By comparison, the IBM PC XT (introduced in March 1983) used the older 4.77 MHz Intel 8088 processor. 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. The IBM PC/AT, introduced later in 1984, used the newer 6 MHz Intel 80286. 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 supports up to 768 KB of RAM, significantly more than the 640 KB limit imposed by the IBM architecture. It uses 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 has both "Tandy" and "TRS-80" logos on its case, marking the start of the phaseout of the "TRS-80" brand.