Watch the world's oldest digital computer boot

A Harwell Dekatron dating back to 1951 has been rebooted after three years of restoration.

Otherwise known as the Wolverhampton Instrument for Teaching Computing from Harwell, or WITCH, the Harwell Dekatron (named for the dekatrons it used as memory) hails — funnily enough — from Harwell, Oxfordshire, in the UK. Construction began in 1949, and was completed in 1951.

Coming in at around 2500 kilograms, the computer was designed to perform calculations, a task that it performed very slowly, but continuously and autonomously, from input data fed to it by scientists. This was an advantage it held over smaller hand calculators, since its users could just walk away and perform other tasks while it worked.

However, it was superseded by 1957, and retired to the Birmingham Museum of Science in 1973. Finally, it was disassembled in 1997, when the museum closed, and put into storage at the Birmingham City Council Museums Collection Centre — until its recovery by The National Museum of Computing in 2009.

It was booted up again for the first time this week, and it still works perfectly.

Via www.bbc.co.uk