. A very rare part from one of the first computers in the world, the EDSAC (Electronic Delay Storage Automatic Calculator), has been discovered in the United States. It is believed that other parts could still exist, according to those involved in the reconstruction. The Chassis 1A, which was used to house 28 of EDSAC’s valves, was the part that came back to life. It has been donated by the EDSAC reconstruction group at The National Museum of Computing in Bromham (Bedfordshire), England. On display is the ongoing reconstruction of EDSAC. It was built originally at Cambridge University in late s. They expect to complete the reconstruction later in the year. The display has been a hit with many educational groups who visit the Museum. Robert Little donated Chassis 1A to the Museum, which is a Storage Regeneration Unit that was part of one of the first computer systems in the world. (Image: National Museum of Computing) The Chassis piece that was recovered from EDSAC’s decommissioning in the 1950s is believed to have been sold at an auction. Andrew Herbert, the leader of EDSAC’s reconstruction, stated that details of the “auction” are not clear, but it is possible for other components of EDSAC to still be available and may even exist in Cambridge, where they could have been stored in sheds or garages. After reading the story about TNMOC’s rebuild of EDSAC, Robert Little from Allentown in Pennsylvania donated the Chassis. It was a Chassis he had purchased from Robert E. Clark in 1969,, who lived at that time in Cambridge, England. Clark previously purchased three of the four EDSAC racks. He had intended to transform them into bookshelves. Although the other chassis were eventually discarded it’s possible some might have been donated to friends. Mister Little stated that Dr. Clark is unlikely to be found anymore EDSAC components. In 1984., Dr Clark died. He died in 1984. It is possible that Dr. Clark was bidding on the scrap metal dealer in the area when the EDSAC parts were won at the auction. “I am optimistic that others who worked and built with EDSAC preserved other mementos until now.” Andrew Herbert (EDSAC Project Leader) with Chassis 1A, the original that was rediscovered. Image: National Museum of Computing. Mr. Herbert stated that Chassis 1A was very damaged by corrosion. He also said that much of the wiring had escaped from its tag strips. This particular chassis would require a lot of work to restore it to its original condition. We hope to be able to reuse some valves in the reconstructed EDSAC, provided they remain functional. This will allow us to make a tangible connection to the original machine. As many as 42 this type were found in the original EDSAC, we believe. Only three of these chassis were believed to exist when EDSAC was shut down. One in Cambridge University Computer Laboratory, one in London Science Museum, and one at the Computer History Museum Silicon Valley. It’s exciting to imagine that there might have been more pieces of the original EDSAC. The idea of finding the first computer auction is exciting! Many important advances in computing have been made possible by Sir Maurice Wilkes. Image: National Museum of Computing. The EDSAC chassis was one of the key components. EDSAC was modularly built and had 12 horizontal racks that could hold up to 14 individual chassis. Every chassis contained all of the functional units of the computer. There were approximately seventy types of chassis at the time. Some were duplicated while others were only represented once. The Chassis Type 1A Storage Regeneration Unit kept data in a short- or long-term tank. There were 42 Store Regeneration Units in total. The Museum says that all the chassis variations look very similar. They each have two rows of 14 hole each for valve-holders. This allows each chassis to support 28 vales. Each EDSAC chassis can only be built with three pentodes and two diode gates. This makes them almost identical to modern integrated circuits. The EDSAC Project Team recently discovered Chassis 1A. Some early computer diagrams, which had been stored for many decades, were rediscovered in Video – EDSAC Recreation Overview The video gives an overview of the EDSAC project, which was the first computer with users.
