Pilot ACE

The Pilot ACE was one of the first computers built in the United Kingdom, at the National Physical Laboratory (NPL) in the late 1940s.

Related Topics:
Computer - United Kingdom - National Physical Laboratory - 1940s

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It was a preliminary version of the full ACE, which had been designed by Alan Turing. After Turing left NPL (in part because he was disillusioned by the lack of progress on building the ACE) James H. Wilkinson took over the project, Harry Huskey helped with the design. The Pilot ACE ran its first program on May 10, 1950 and was demonstrated to the press in December 1950.

Related Topics:
ACE - Alan Turing - James H. Wilkinson - Harry Huskey - 1950

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Although originally intended as a prototype, it became clear that the machine was a potentially very useful resource, especially given the lack of other computing devices at the time. After some upgrades to make operational use practical, it was into service in late 1951, and saw considerable operational service over the next several years.

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It had approximately 800 vacuum tubes, and used mercury delay lines for its main memory. The original size of the latter was 128 32-bit words, but that as later expanded to 352 words; a 4096-word drum memory was added in 1954. Its basic clock rate, 1 megahertz, was the fastest of the early British computers. The time to execute instructions was highly dependant of where they were in memory (due to the use of delay line memory). An addition could take anywhere from 64 microseconds to 1024 microseconds.

Related Topics:
Vacuum tube - Mercury - Delay lines - Main memory - Drum memory - 1954 - Megahertz - Microseconds

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The machine was so successful that a commercial version of it, named the DEUCE, was constructed and sold by the English Electric Company.

Related Topics:
DEUCE - English Electric

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The Pilot ACE was shut down in May, 1955, and was given to the Science Museum, where it remains today.

Related Topics:
1955 - Science Museum

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