- IBM 801
The 801 was a
RISC CPU designed by IBM in the 1970s, and used in various roles in IBM until the 1980s.The 801 started as a pure research project led by
John Cocke at theThomas J. Watson Research Center in building 801. They were looking for ways to improve performance of their existing machines, studying traces of programs running onSystem/370 mainframes and looking at the compiler code. From this project led the idea that it was possible to make a very small and very fast core, which could then be used to implement themicrocode for any machine.The project then moved on to produce the design as a CPU, also called the 801. The resulting CPU was operational by the summer of 1980 and was implemented using Motorola MECL-10K technology on large wire wrapped custom boards. The CPU was clocked at 66 ns cycles (approximately 15.15 MHz) and could compute at the then-fast speed of approximately 15 MIPS. This prototype design was a 24-bit implementation without
virtual memory . The 801 architecture was used in a variety of IBM devices includingchannel controller s for their 370 mainframes, various networking devices, and eventually the IBM 9370 mainframe core itself.In the early 1980s the lessons learned on the 801 were put back into the new "America Project", which led to the
IBM POWER architecture and theRS/6000 deskside scientific microcomputer.John Cocke later won both theTuring award and thePresidential Medal of Science for his work on the 801.External links
* [http://domino.watson.ibm.com/tchjr/journalindex.nsf/0/22d06c5aa961e78085256bfa0067fa93?OpenDocument The evolution of RISC technology at IBM by John Cocke] – IBM Journal of R&D, Volume 44, Numbers 1/2, p.48 (2000)
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