Electronic Delay Storage Automatic Calculator (EDSAC) was an early British computer. The machine, having been inspired by John von Neumann's seminal First Draft of a Report on the EDVAC, was constructed by Maurice Wilkes and his team at the University of Cambridge Mathematical Laboratory in England. EDSAC was the first practical stored-program electronic computer.
The project was supported by J Lyons & Co Ltd, a British firm that was rewarded with the first commercially applied computer, LEO I, based on the EDSAC design. EDSAC ran its first programs on 6 May 1949, when it calculated a table of squares and a list of prime numbers.