The DEC Alpha, also known as the Alpha AXP, is a 64-bit RISC microprocessor originally developed and fabricated by Digital Equipment Corp. (DEC), which used it in its own line of workstations and servers. Designed as a successor to the VAX line of computers, it supported the VMS operating system, as well as Digital UNIX. Later open source operating systems also ran on the Alpha, notably Linux and BSD UNIX flavours. Microsoft supported the processor until Windows NT 4.0 SP6 but did not extend Alpha support beyond release candida ...
Alpha was born out of an earlier RISC project named PRISM, itself the final product of several earlier projects. DEC had been marketing the DECstation line of workstations based on the MIPS architecture, and unsurprisingly PRISM shared many features with MIPS. Among the differences between PRISM and MIPS, however, was that PRISM supported a user-programmable microcode known as Epicode. PRISM had been designed with the intent of releasing a new operating system along with it, known as Emerald, which would allow it to run "native ...
