Technology History | David Attenborough Building, Cambridge — EDSAC Made Computing a Service

Most early computers were events. This one was a service.

The University's Mathematical Laboratory was founded in 1937 in the north wing of the former Anatomy School, on this site, to develop computing techniques and run a computing facility for anyone in Cambridge who needed one.

By 1945 it had a single full-time employee, Maurice Wilkes, who became its director.

In 1946 a friend returning from America brought him a copy of von Neumann's First Draft of a Report on the EDVAC. Wilkes went to the Moore School lectures in Philadelphia that summer and came back intending to build not the cleverest possible machine but a working one.

That choice is the whole story. He used proven components and a conservative design, and on 6 May 1949 the Electronic Delay Storage Automatic Calculator ran its first program, a table of squares.

Cambridge is careful about the claim, and so should anyone else be: Manchester's Baby had run a stored program eleven months earlier. EDSAC was the first machine of its kind to give a practical, regular computing service.

It weighed about two tons and filled a room. Programs arrived on paper tape fed in by hand, and researchers waiting their turn pegged their tapes to what was, by the charity that later commemorated it, literally a washing line.

Scientists across the university queued for it because the alternative was a room of people with mechanical calculators. Work that had been impractical became a morning's run, and the University credits EDSAC with contributing to three Nobel Prizes awarded in the 1960s and 1970s.

A catering company noticed. J. Lyons and Co. built LEO on EDSAC's design, and ran the world's first regular business computing job on it in 1951.

The Mathematical Laboratory building is gone, replaced at the end of the 1960s. The David Attenborough Building now stands where EDSAC stood, and the Museum of Zoology inside it is free to enter.

The commemoration is very recent and not quite finished. Cambridge Past, Present & Future unveiled a blue plaque for EDSAC on 23 June 2026 — the scheme's first for the making of a machine rather than a person — at a ceremony in the Department of Computer Science and Technology, with installation on this building promised for later in the summer.

Whether it is yet on the wall is worth checking before you make the trip.

Sources: University of Cambridge and Cambridge Past, Present & Future on the June 2026 plaque; Cambridge Independent, 2026; Whipple Museum and the Department of Computer Science and Technology on the Mathematical Laboratory and EDSAC's origins. Cover photo: PJeganathan, CC BY-SA 4.0, via Wikimedia Commons, showing the building's entrance sign rather than EDSAC, of which no freely licensed photograph was found.