6502 info taken from Wikipedia.org
The MOS Technology 6502 is an 8-bit microprocessor designed by Chuck Peddle for MOS Technology in 1975. When it was introduced it was the least expensive full featured CPU on the market by far, at about 1/6th the price, or less, of competing designs from larger companies such as Motorola and Intel. It was nevertheless faster than most of them, and, along with the Zilog Z80, sparked off a series of computer projects that would eventually result in the home computer revolution of the 1980s. The 6502 design was originally second-sourced by Rockwell and Synertek and later licensed to a number of companies; it is still made for embedded systems.
The 6502 was used, among others, for Commodore's 8-bit machines.
Originally the CPC was destined to be designed around the 6502 processor. But when Amstrad approached Locomotive Software to develop a Basic for it with a very tight deadline, Locomotive PLC, who already had a Z80 Basic in the works, urged and convinced Amstrad to switch to the Z80.