Nevertheless it was an interesting exercise to rebuild the thing in the first place, given the paucity of information about the device. Its creator, Tommy Flowers, arguably did more than nay other Briton to bring a speedy end to the war and that so few know anything about him is a crying shame.

The reason for this lies mainly in the Cold War and the paranoia it spawned. The very existence of Colossus wasn't even acknowledged until after the news the Electronic Numerical Integrator And Computer (ENIAC) had been built – leading to endless transatlantic arguments among geeks as to who built the first computer.

Flowers was awarded a small honour and a payment of just £1,000 after the war's end – which was less than he spent to build the thing in the first place. He was then forced to burn his blueprints and watch as the Colossus machines were broken up to ensure their secrets were kept safe. A sad end for an inspired idea.