Throwback Tech: The world’s oldest working computer

In 2012, the oldest working computer sprung back to life as part of a resurrection program at The National Museum of Computing (TNMOC) in the U.K.. The Harwell Dekatron was produced in 1951, and was first used at the Harwell Atomic Energy Research Establishment shortly after its creation. Users at this research facility mainly performed calculations on the computer, relying on the device for its accuracy. The computer was not binary, but it could perform calculations involving decimals. This feature is identifiable by its flashing Dekatron valves. When multiplying two numbers, the computer would take 10 seconds to process the equation and produce an answer. The Harwell Dekatron was the world’s first semi-programmable computer.

In 1957, the machine started to become obsolete for the scientists at Harwell. It was then moved to Wolverhampton. A scientist created a competition where educational facilities could propose the best use for it. The school with the best proposition would receive the computer. Wolverhampton and Staffordshire Technical College won the contest, and the computer was renamed the WITCH, an acronym for the Wolverhampton Instrument for Teaching Computation from Harwell. The college greatly used the computer for educational purposes until 1973. 

In 1973, the WITCH was declared the world’s most durable computer, and was then moved to the Birmingham Museum of Science and Industry where it remained until it was brought to TNMOC in 2009 for restoration. 

Weighing in at 2.5 tons, the 61-year-old computer has 828 flashing Dekatron counter tubes, 480 relays, and a bank of paper tape readers that help the machine start running.  There are 131 other functional valves inside of the computer. The 7073 contacts/relay switches, 26 high-speed relays, and 18 switches have been restored to run smoothly. The computer stands 2 meters high, 6 meters wide, and 1 meter deep with a power consumption of 1.5 kW.

In 2012, the WITCH was displayed for visitors at The National Museum of Computing. The computer has found its final home. 

Story via TNMOC.org