and PCX). They were first used in a new series of HP 3000 machines in the late 1980s – the 930 and 950, commonly known at the time as Spectrum systems, the name given to them in the development labs. These machines ran MPE-XL. The HP 9000 machines were soon upgraded with the PA-RISC processor as well, running the HP-UX version of UNIX. Other operating systems ported to the PA-RISC architecture include Linux, OpenBSD, NetBSD and NeXTSTEP. An interesting aspect of the PA-RISC line is that most of its generations have no Level 2 cache. Instead large Level 1 caches are used, formerly as separate chips connected by a bus, and now integrated on-chip. Only the PA-7100LC and PA-7300LC have L2 caches. Another innovation of the PA-RISC is the addition of vector instructions (SIMD) in the form of MAX, which were first introduced on the PA-7100LC. Precision RISC Organization, an industry group led by HP, was founded in 1992, to promote the PA-RISC architecture. Members included Convex, Hitachi, Hughes Aircraft, Mitsubishi, NEC, OKI, Prime, Stratus, Yokogawa, Red Brick Software, and Allegro Consultants, Inc. The ISA was extended in 1996 to 64 bits, with this revision named PA-RISC 2.0. PA-RISC 2.0 also added fused multiply–add instructions, which help certain floating-point intensive algorithms, and the MAX-2 SIMD extension, which provides instructions for accelerating multimedia applications. The first PA-RISC 2.0 implementation was the PA-8000, which was introduced in January 1996. CPU specifications See also Amiga Hombre chipset – A PA-7150-based chipset with a complete multimedia system for Commodore Amiga References External links LostCircuits Hewlett Packard PA8800 RISC Processor overview HP's documentation – page down for PA-RISC, architecture PDFs available OpenPA.net Comprehensive PA-RISC chip and computer information chipdb.org Images of different PA-RISC processors HP microprocessors Instruction set architectures Computer-related introductions in 1986