CDC Cyber

The CDC Cyber range of mainframe-class supercomputers (except for the Cyber 18 and Cyber 1000 minicomputers) were the primary products of Control Data Corporation (CDC) during the 1970s and 1980s. In their day, they were the computer architecture of choice for scientific and mathematically intensive computing. They were used for modeling fluid flow, material science stress analysis, electrochemical machining analysis, probabilistic analysis, energy and academic computing, radiation shielding modeling, and other applications.

The Cyber line included five very different models of computer:

Primarily aimed at large office applications instead of the traditional supercomputer tasks, some of the Cyber machines nevertheless included basic vector instructions for added performance in traditional CDC roles.

The Cyber 70 and 170 architectures were successors to the earlier CDC 6600 and CDC 7600 series and therefore shared almost all of the earlier architecture's characteristics. The Cyber-70 series was a minor upgrade from the earlier systems. The Cyber-170 series represented CDCs move from discrete electronic components and core memory to integrated circuits and semiconductor memory. The Cyber-170/700 series was a late-1970s refresh of the Cyber-170 line.

The central processor (CPU) and central memory (CM) operated in units of 60-bit words. In CDC lingo, the term "byte" referred to 12-bit entities (which coincided with the word size used by the peripheral processors). Characters were six bits, operation codes were six bits, and central memory addresses were 18 bits. Central processor instructions were either 15 bits or 30 bits. The 18-bit addressing inherent to the Cyber 170 series imposed a limit of 262,144 (256K) words of main memory, which was semiconductor memory in this series. The central processor had no I/O instructions, relying upon the peripheral processor (PP) units to do I/O.

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