An 8-bit microprocessor from Zilog, a company founded by former Intel engineers. The Z80 has a 16-bit address bus, yielding a 64-kilobyte addressable memory space, and an 8-bit data bus. A descendant of the Intel 8080, it was the favored processor in the days of the CP/M operating system. One of the most popular computers of the early 1980s, the Radio Shack TRS-80, was based on this chip. See also CP/M.