PowerPC

PowerPC (with the backronym Performance Optimization With Enhanced RISC – Performance Computing, sometimes abbreviated as PPC) is a reduced instruction set computer (RISC) instruction set architecture (ISA) created by the 1991 Apple–IBM–Motorola alliance, known as AIM. PowerPC, as an evolving instruction set, has been named Power ISA since 2006, while the old name lives on as a trademark for some implementations of Power Architecture–based processors. PowerPC was the cornerstone of AIM's PReP and Common Hardware Reference Platform (CHRP) initiatives in the 1990s. Originally intended for personal computers, the architecture is well known for being used by Apple's Power Macintosh, PowerBook, iMac, iBook, eMac, Mac Mini, and Xserve lines from 1994 until 2006, when Apple migrated to Intel's x86. It has since become a niche in personal computers, but remains popular for embedded and high-performance processors. Its use in the 7th generation of video game consoles and embedded applications provide an array of uses, including satellites, and the Curiosity and Perseverance rovers on Mars. In addition, PowerPC CPUs are still used in AmigaOne and third party AmigaOS 4 personal computers. PowerPC is largely based on the earlier IBM POWER architecture, and retains a high level of compatibility with it; the architectures have remained close enough that the same programs and operating systems will run on both if some care is taken in preparation; newer chips in the Power series use the Power ISA. The history of RISC began with IBM's 801 research project, on which John Cocke was the lead developer, where he developed the concepts of RISC in 1975–78. 801-based microprocessors were used in a number of IBM embedded products, eventually becoming the 16-register IBM ROMP processor used in the IBM RT PC. The RT PC was a rapid design implementing the RISC architecture. Between the years of 1982 and 1984, IBM started a project to build the fastest microprocessor on the market; this new 32-bit architecture became referred to as the America Project throughout its development cycle, which lasted for approximately 5–6 years.