About 30 years ago today - Intel introduced the 8086 cpu which was the first in a long line of cpu-chips that are still found in computers today! The 4004, 8008, 8085, 8086, 186, 286, 386, SX/DX, 80486SX/DX/DX2/DX4, Pentium, Pentium MMX, PentiumII/Celeron, PentiumIII/Celeron, Pentium IV/Celeron etc. Isn't it amazing that todays quadcore machines still share quite a bit of the same instruction set of the old 8086 cpu?

The 8086's instruction-set consists of more than hundred op-codes which were on their turn largely based on the older 8008 chip. But the two were not binary compatible cpus. A company called Computer Terminal Cooperation was responsible for inventing the x86-commandset (originally for the 8080 which is considered to be one of the first real CPUs meant for desktop computing). This command-set/instruction set was acquired by Intel because of time pressure. At the time Intel was actually working on its own more enhanced instruction-set which was capable of 32-bit processing and a lot of other fancy techniques like 'automatic garbage collection' and 'virtual memory'. The slow development of that instruction set including a cpu-chip was put on hold and Intel chose to implement the x86 instruction set only as a temporary solution in order to be able to quickly bring out a desktop cpu. Well it turned out to be far from a temporary solution. And the 8086 still is considered a rush job, as the chip was developed in under two years.

What is also striking is the fact that Intel stuck with the CISC instruction set whereas other alternative CPU-manufacturers of the time all adopted RISC instruction sets. Of course there were other companies that invested in the CISC x86 instruction set. One of those was IBM and it developed its own version of the 8086. The 8088 chip was a compatible chip introduced by IBM and was instruction compatible with the 8086 and this chip has been 'cloned' ever since and used in IBM-compatibles. IBM used its leverage to force Intel into sharing its x86 technology with other companies like NEC and AMD. Which resulted in the first wave of alternative x86 compatible desktop cpus. In order to stay ahead of the game Intel just had to rekindle all the nice advanced instruction set ideas and sort of welded all of it on top of the existing x86 instruction set, the 286 was born as a result. The rest is history.

Enough geek-info for now, and Bill please correct me if I am wrong - which I undoubtedly will be ;-)