Reduced instruction set computers

Abstract

Two of the best known families of microprocessor are those based on the Motorola 68000 and Intel 8086 architectures, the 680×0 family gaining popularity through its association with the Apple Macintosh and the 80×86 family through association with the original IBM PC. By adopting this family approach, first introduced for IBM mainframes in the mid-sixties, processor designers have been able to take advantage of the implementation techniques and speed increases offered by advances in Very Large Scale Integration (VLSI) technology, while continuing to support a common architecture. Supporting a common architecture is important because it allows software written for older machines to run on newer ones and thus protects the customers’ software investment.