DEC Alpha

What Does DEC Alpha Mean?

Alpha was a microprocessor from Digital Equipment
Corporation which was based on 64-bit reduced instruction set computing (RISC). It was designed
to replace DEC’s 32-bit VAX complex instruction set. The DEC Alpha
microprocessors were used in a variety of Digital Equipment Corporation’s
servers and workstations. The Alpha
architecture was sold by Digital
Equipment Corporation to Compaq, who later phased it out and sold all Alpha-related intellectual properties to Intel.


Techopedia Explains DEC Alpha

The first few Digital Equipment Corporation Alpha chips were quite innovative for their time. The first version, Alpha 21064, was in fact the first CMOS-based microprocessor to have the operating frequency matching the higher-powered ECL mainframes and minicomputers. The DEC Alpha did not have suppressed instructions, branch delay slots or store instructions. It also did not make use of condition codes mainly used in integer instructions. The Alpha made use of 64-bit linear virtual address space with absolutely no memory segmentation. The architecture for Alpha also made use of a set of 32 integer registers and 32 floating-point registers, two lock registers, a floating-point control register and a program counter.

As far as the microprocessor industry is concerned, the Alpha microprocessor holds its place in history due to the manner in which it was implemented. The Alpha microprocessor, when implemented, showed that manual circuit design is possible and could lead to a simple, transparent and clean architecture, and thereby higher operating frequencies compared to designs done with the help of automated design systems.


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Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.