OpenPA.net
PA-RISC information - since 1999

PA-RISC Processors

Apollo PRISM Processor

Overview

PRISM was a RISC processor developed by Apollo Computer Inc. during the 1980s and released in 1988. PRISM was the first commercial CPU architecture with a VLIW (Very Long Instruction Word) design and was implemented on CMOS on a processor board consisting of eleven VLSI chips at 20 MHz clock. For the time, PRISM was billed as one of the fastest RISC processors, and was able to support up two four CPUs in a single system (SMP).

The processors were used in Apollo's own Domain 10000 (DN10000) line of computers, with a PRISM II processor already being planned and designed. After the acquisition by HP in 1989, the Apollo products were integrated into the HP line up, but the PRISM II processor dropped. Still, in 1989 HP was communicating an upgraded PRISM processor (DN10000TX upgrade) – with a streamlined architecture, higher clock, double computing power (from 22 to 44 MIPS), increased caches to be fabbed by HP’s Colorado ASIC factory in 1991 in 1.0µ.

PRISM was sometimes codenamed A88K (or a88k), not to be confused with the Motorola M88K 88000 RISC processors, after Apollo earlier used Motorola 68000 processors in its workstations. Parts of the PRISM architecture were later reused in PA-RISC, including the FPU.

Details

Used in

DN10000TX (second generation)

References

  1. The DN 10000TX: a new high-performance PRISM processor, COMPCON Spring ’91 Digest of Papers, 1991
  2. APOLLO COMPUTER LAUNCHES ITS 64-BIT PRISM RISC MACHINE, Tech Monitor archive, February 29, 1988
  3. WHY APOLLO COMPUTER RECKONS IT HAS OUTDONE SUN IN THE RISC STAKES, Tech Monitor archive, March 14, 1988
  4. Apollo CPUs, Apollo/DOMAIN Computers at zepa.net, 2003 (archive.org mirror from 20030201)
  5. HP unveils plan for new PRISM CPU, Hewlett Packard, Press Release October 1989 (1000bit.it archive)

↑ up