The first stored programme computer ever in the world, the pioneering British EDSAC (Electronic Delay Storage Automatic Calculator) was put at work 65 years ago. Drawing on the principles of John von Neumann, Maurice Wilkes (1913-2010) and his team built the machine at the Mathematical (later Computer) Laboratory of Cambridge University. EDSAC ran its first programme on 6 May 1949.

In accordance with state of the art technology at the time, EDSAC had a huge size: the two-metre-tall machine occupied four square metres, and comprised of three thousand tubes. Commands arrived on paper-tape, and EDSAC could do 650 instructions per second. It did calculations 1500 faster than humans.

The machine was used by a great number of scientists, mathematicians, and engineers including several Noble Prize winners: John Kendrew, Max Perutz, Andrew Huxley, Martin Ryle. None of them failed to make reference to EDSAC at the award ceremony.

Financial support for the project came from a number of sources, for instance, from J. Lyons and Co., the food manufacturing, hotel and restaurant conglomerate. Later on Lyons took over the complete management, and developed LEO I, the first computer designed for business purposes. LEO was inspired by and modelled after EDSAC.

EDSAC worked for nearly 10 years (until 11 July, 1958) at the University of Cambridge before it was replaced by EDSAC2 created by the same team of developers. Its successor was used until 1965. EDSAC2 was the first computer to contain microprogrammed control units.

The Computer Conservation Society (CCS, www.computerconservationsociety.org), dedicated to the restoration of old computers, announced on 3 January, 2011 that a replica of the legendary EDSAC would be recreated at Bletchley Park. The project is managed by Andrew Herbert, one of Wilkes’ former students.