[blowski]

The Colossus Machine was a huge code-breaking computer built in the UK during World War 2. Multiple models were built but most were destroyed by the intelligence services at the end of the war. So far as I understand, it calculated possible keys being used on encrypted radio messages broadcast by the Nazis.

This is a 3D model I stumbled upon that shows how it works in intricate detail.

The whole story behind Colossus is fascinating. There is a replica in the National Museum of Computing in Bletchley Park.