Britain’s “˜Oldest’ Computer To Be Restored

Britain’s oldest original computer is being sent to the National Museum of Computing at Bletchley, where it will undergo a one-year restoration project.

The Harwell system was originally designed in 1949 to perform mathematical calculations, and ran from 1951 to 1973.

The state-of-the-art computer measured roughly 8 ft. x 16 ft.  when it was originally built by a team of three people at the Atomic Energy Research Establishment in Harwell, Oxfordshire. 

The establishment staff used the system, which performed the work of six to ten people, for seven years until they received their first commercial computer.

The Harwell was ultimately superseded by transistor-based systems.

Dick Barnes, who helped build the system, said the establishment research was for civilian nuclear power projects, at least officially.

“Officially it was to help with general background atomic theory and to assist in the development of civilian power,” he said during an interview with BBC News.

“Of course, it [the Atomic Energy Research Establishment] had connections to the nuclear weapons program,” he said.

Although the Harwell machine was not the first computer built in Britain, it had one of the longest service lives. 

“We didn’t think we were doing anything pioneering at the time,” said Mr. Barnes, referring to the Harwell system’s inception.

“We knew the Manchester Baby and Cambridge’s EDSAC were already up and running. Both these projects had large teams and we felt like a poor relation,” he said.

“Looking back, hardly any of us were computer literate and it’s astonishing that we managed stored computing at all.”

Unlike some of its predecessors, the Harwell computer is seemingly modern in that it uses a single memory to store data and programs.

Kevin Murrell, director of The National Museum of Computing at Bletchley Park, told BBC News that the Harwell had some of the characteristics of contemporary machines.

“The machine was a relay-based computer using 900 Dekatron gas-filled tubes that could each hold a single digit in memory – similar to RAM in a modern computer – and paper tape for both input and program storage,” he said.

The Harwell was offered as a prize for colleges after it was retired from service, with Wolverhampton and Staffordshire Technical College taking ownership and renaming the system “the WITCH” — Wolverhampton Instrument for Teaching Computing from Harwell.

The device was used as part of the college’s computer education program until 1973, when it went on display at Birmingham Science Museum.  It was later put into storage at Birmingham City Council Museums’ Collection Centre.

The Harwell is now being sent to the National Museum of Computing in Bletchley, where a technical team will restore the system to proper working order.

Mr. Barnes called the idea of seeing the Harwell computer running again after more than 36 years “very exciting”.

“I still don’t know how they managed to find so many spare parts, but I think they have a very good chance of getting it going again,” he said.

The Harwell system had many principal predecessors, such as the Ace (parts of which are on display in London’s Science Museum), the Electronic Delay Storage Automatic Calculator (EDSAC) and Manchester’s Small-Scale Experimental Machine (SSEM) — nicknamed Baby, which has since been rebuilt.

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