The National Museum of Computing fires up the Harwell Dekatron, aka Wolverhampton Instrument for Teaching Computation — WITCH. The world’s oldest working original digital computer, first built in 1951, two-and-a-half tons, 828 flashing Dekatron valves, and 480 relays of it. “In 1951 the Harwell Dekatron was one of perhaps a dozen computers in the world.” It doesn’t calculate in binary code, but decimal code, hence the name “Dekatron.”
The Harwell Atomic Energy Research Establishment provided the Dekatron its first tasks, cranking out calculations formerly done by hand. When it passed into obsolescence there in 1957, Staffordshire Technical College took the massive computer off Harwell’s hands, and there it became the WITCH, used for teaching purposes over the next sixteen years. When it outlived even its educational use, the WITCH went on display at the Birmingham Museum of Science and Industry.
An operation to boot it up again stared in 2008, it now offers a whirring, clattering, flashing, retro-technological spectacle to new generations of computer enthusiasts.