DEC Alpha

Alpha, originally known as Alpha AXP, is a 64-bit Reduced Instruction Set Computer (RISC) instruction set architecture (ISA) developed by Digital Equipment Corporation (DEC), designed to replace the 32-bit VAX Complex Instruction Set Computer (CISC) ISA and its implementations.

Operating systems that supported Alpha included OpenVMS (previously known as OpenVMS AXP), Tru64 UNIX (previously known as DEC OSF/1 AXP and Digital UNIX), and Windows NT (until 4.0 SP6 and Windows 2000 RC1). Open source operating systems that run on the Alpha are Linux, BSD UNIX (NetBSD, OpenBSD and FreeBSD up to 6.x) and L4Ka::Pistachio.

Emulation

• ES 40 Emulator

External links

• Alpha - documentation at Bitsavers
  • Alpha System Reference Manual - Version 5
  • Alpha System Reference Manual - Version 6
  • Alpha System Reference Manual - Version 7
• What Have We Learned from the PDF’-11 - What We Have Learned from VAX and Alpha
• A Retrospective on What We Have Learned From the PDP-11: What Else Did We Need to Know That Could Have Been Useful in the Design of the VAX-11 to Make Alpha Easier?