The Pilot ACE was one of the first computers built in the United Kingdom, in the late 1940s.

It was a stripped-down version of the full ACE, designed by Alan Turing; after Turing left NPL, dis-illusioned by the lack of progress on building the ACE, James H. Wilkinson took over the project, and got the Pilot ACE constructed and operating by May, 1950.

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.

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

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

Further reading

• Simon H. Lavington, Early British Computers: The Story of Vintage Computers and The People Who Built Them (Manchester University Press, 1980)
• David M. Yates, Turing's Legacy: A History of Computing at the National Physical Laboratory, 1945-1995 (Science Museum, London, 1997)

References

• J. H. Wilkinson, Turing's Work at the National Physical Laboratory and the Construction of Pilot ACE, DEUCE and ACE (in Nicholas Metropolis, J. Howlett, Gian-Carlo Rota, (editors), A History of Computing in the Twentieth Century, Academic Press, New York, 1980)
• Martin Campbell-Kelly, Programming the Pilot ACE (in Annals of the History of Computing, Vol. 3 (No. 2), 1981, pp. 133-162)

External links

• The Pilot ACE at the Science Museum
  • The Pilot ACE today