Page "DEC Alpha" Paragraph 11

Another study was started to see if a new RISC architecture could be defined that could directly support the VMS operating system.

The new design used most of the basic PRISM concepts, but was re-tuned to allow VMS and VMS programs to run at reasonable speed with no conversion at all.

The decision was also made to upgrade the design to a full 64-bit implementation from PRISM's 32-bit, a conversion all of the major RISC vendors were undertaking.

Eventually that new architecture became Alpha.

The primary Alpha instruction set architects were Richard L. Sites and Richard T. Witek.

The PRISM's Epicode was developed into the Alpha's PALcode, providing an abstracted interface to platform-and processor implementation-specific features.