Harwell Dekatron Computer in action at The National Museum Of Computing
The Harwell Dekatron Computer (the "WITCH") built in 1951. It has been restored and is in action at The National Museum of Computing. It does arithmetic at approximately human speed, but with more accuracy and endurance. Watching the blinking lights allows you to follow the instructions and the changing data, as it runs the Squares program displayed on the panels. Permission for use granted by TMNOC.