Lost EDSAC diagrams reveal secrets of early computers at National Museum of Computing

By Culture24 Reporter | 27 June 2014

Some of the earliest diagrams of a pioneering computer have been rediscovered after 60 years at the National Museum of Computing

a photo of a man in lab coat and a woman in glasses looking at a large plan in front of a large computer
EDSAC (January 1949)© Computer Laboratory, University of Cambridge. Reproduced by permission
Volunteers at The National Museum of Computing rebuilding one of the world’s first computers – the Electronic Delay Storage Automatic Calculator or 'EDSAC' – are celebrating after discovering a batch of 60-year-old computer plans.

Representing some of the earliest diagrams of a computer, the discovery is giving the team fresh insights into their ongoing reconstruction of the world's first general purpose computer.

Designed by Sir Maurice Wilkes, the EDSAC was built in the University of Cambridge immediately after World War II.

It was the world's first practical general purpose computer, transformeing research possibilities for many academics and even helping three experts in Nobel-prize winning work. The EDSAC design was later developed to create LEO, the world's first business computer.

The 19 highly detailed circuit diagrams have been given to the EDSAC team by John Loker, a former engineer at the University of Cambridge Mathematical Laboratory, who kept the circuit diagrams after discovering them in 1959 in “a lot of stuff piled up ready to be thrown away” shortly after EDSAC had been decommissioned.

a photo of three men holding a large piece of paper in front of a large computer
Chris Burton, John Loker and Andrew Herbert take a look at one of the diagrams
“I'm a collector, so I couldn't resist the urge to rescue them,” added Loker.

“It wasn't until I visited TNMOC recently and learned about the EDSAC Project that I remembered I had the diagrams at home, so I retrieved them and gave them to the project."

Many of them, which date from between 1949 and 1953, were drawn after EDSAC had been constructed, probably as some sort of aid in refining the original machine and in designing the next.

“Thankfully the documents confirm that the reconstruction we are building is basically correct," said Andrew Herbert, the project leader.

"But they are giving us some fascinating insights about how EDSAC was built and show that we are very much in tune with the original engineers: both teams have been exercised by the same concerns.

"Importantly, the drawings clearly show that the aim of EDSAC's designer, Sir Maurice Wilkes, was to produce a working machine quickly rather than to create a more refined machine that would take longer to build.

"The refinements could come later - and many did, as the sequence of diagrams over the five-year period shows."

The reconstruction of EDSAC is due for completion late in 2015 and can already be seen as a work in progress by visitors to The National Museum of Computing. The ongoing reconstruction story featuring videos of progress at different stages can be seen at www.edsac.org.

What do you think? Leave a comment below.

You might also like:

Flossie the computer is rescued from scrapheap by National Museum of Computing

National Museum of Computing calls on public to help double historic £1 milllion pledge

National Museum of Computing honours Sir Maurice Wilkes by revisiting EDSAC machine

Latest comment: >Make a comment
More on the venues and organisations we've mentioned:
  • Back to top
  • | Print this article
  • | Email this article
  • | Bookmark and Share
    Back to article
    Your comment:
    DISCLAIMER: Reader comments posted at www.culture24.org.uk are the opinion of the comment writer, not Culture24. Culture24 reserves the right to withdraw or withhold from publication any comments that are deemed to be hearsay or potentially libellous, or make false or unsubstantiated allegations or are deemed to be spam or unrelated to the article at which they are posted.