6th May 1949
EDSAC runs its first program

The Electronic Delay Storage Automatic Calculator (EDSAC) was the first practical stored-program computer to operate a regular computing service.

EDSAC was built by Maurice Wilkes at the University of Cambridge Mathematical Laboratory.

On 6th May 1949, EDSAC performed its first calculation, running a program written by Beatrice Worsley to calculate the squares of numbers.

J. Lyons & Co. Ltd., a British firm, helped fund the EDSAC project with a grant of £3000. In return, Lyons were given permission to build a copy once EDSAC was complete. The Lyons machine based on the EDSAC design, LEO I, was the first commercial computer.

EDSAC used the following components:

• 5-hole punched paper tape for input
• A teleprinter for output
• Mercury delay lines for memory
• Vacuum tubes for logic

Related information:

• Centre for Computing History: Maurice Wilkes
• Centre for Computing History: Beatrice Worsley
• Whipple Museum of the History of Science: The EDSAC and Computing in Cambridge
• University of Warwick: The Edsac Simulator

Image:

• Maurice Wilkes and Bill Renwick in front of the completed EDSAC
  Credit: Copyright Department of Computer Science and Technology, University of Cambridge. Reproduced by permission.

Related Items in the Collection:

51856 EDSAC log

LEO I computer becomes operational

Introduction to Programming for the EDSAC