Intel was one of the pioneering Microprocessor manufacturers when it created the 4004 processor in 1971. This was followed by the 8080 processor in the late 70's, which was developed into the 8086 and 8088 processors in 1979. It was only when, in 1981 IBM selected the 8086 processor for its new Personal Computer, the IBM PC, did the Intel processor design gain its opportunity to be used widely.The Intel 8086/8088 range of processors were based upon Complex Instruction Set Computing (CISC) which allows the number of bytes per instruction to vary according to the instruction being processed. This is unlike Reduced Instruction Set Computing (RISC) which has fixed length instructions (typically set at 32 bits each). The architechture pioneered by Intel has become known as "x86" due to the early naming system where processors were called 8086, 80186 (not used in PC's), 80286, 80386, and 80486.
