Five Things To Know About The EDSAC Computer

The Computer Conservation Society announced yesterday that a working replica of the EDSAC is to be built at the National Museum of Computing in Bletchley Park.

The EDSAC (Electronic Delay Storage Automatic Calculator), the first serial electronic calculating machine to operate a regular computing service, is widely regarded as the first commercial "computer" and saw use well into the 1950's. The machine was launched on the 6th of May 1949, nearly seven years after the Colossus Mark 1 was built at Bletchley Park.

To celebrate, we've compiled a list of five interesting facts about the EDSAC.

There's a free EDSAC emulator available online, courtesy of Martin Campbell Kelly from the University of Warwick, which faithfully reproduces the way the calculator worked as well its user interface. The software should be compatible with Windows, Linux and Macintosh.

The EDSAC could reach 650 IPS (instructions per second) while, in comparison, the latest Intel Core i7 Extreme Edition i980EE processor runs at 147GIPS, more than 200 million times faster.

The 62 year old calculator used 3000 valves (the equivalent of transistors), had a power consumption of 12kW and occupied a room 5m by 4m - a significant improvement over previous computers like the ENIAC or the Colossus.

In 1952, Professor Alexander S. Douglas implemented a computer game named OXO (basically noughts and crosses) on an EDSAC computer and it is widely regarded as the first ever developed computer game. Unfortunately it didn't sell well, there having been on only one EDSAC running at that time.

The EDSAC was built by the UK, J. Lyons & Co, which is very well known for its other household names, Lyons Maid ice cream and ice lollies, Mr Kipling's Cakes and Lyons Biscuits.