IBM 801

Of 801 was a RISC microprocessor from IBM. It was designed in the 1970s and used in various versions until the 1980s into it.

Development of the 801 began as a pure research project, led by John Cocke at the Thomas J. Watson Research Center in Building 801 They were looking for ways to improve the performance of existing systems, and examined to traces of programs on System/370-Großrechnern and the compiler code. In this project, the idea was that it was possible to produce a very small and very fast CPU core, by which one can execute code for each machine. We reduced this, the instruction set of the most important and fastest instructions.

The project produced the design in the prototype of a CPU, which in 1980 was functional. They used to Motorola's MECL -10K technology on large boards. The CPU was clocked at 66 ns cycles (about 15.15 MHz), and could then deal with an amazing 15 MIPS. The prototype was a 24-bit implementation without virtual memory. 801, the architecture has been employed in various IBM equipment, including channel controller 370 for the systems and likely for the IBM 9370 mainframe core and in the IBM RT.

In the early 1980s, the findings that were obtained with the 801 were introduced into the America Project. This later led to the IBM POWER architecture and the RS/6000 workstations to mainframes.

John Cocke later won the Turing Award and the Presidential Medal of Science for his work on 801