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Colossus

the world’s first digital electronic computer Midlands,

Black-and-white photograph showing two women standing next to a bank of computer equipment.
Wrens operating the Colossus computer, 1943. Science Museum/ Science & Society Picture Library

The Colossus was the world’s first digital electronic computer. Designed by Tommy Flowers (1905-98) at the Post Office Research Station in Dollis Hill, Colossus was taken to Bletchley Park, Buckinghamshire, site of the UK’s main decryption establishment, where it tackled its first coded German messages in 1943.

The machine was used to crack the German Lorentz cipher (a code much harder to crack than that used by the Enigma machine) at Bletchley Park during the Second World War.

Even with its impressive capabilities, Colossus had to be rapidly upgraded, with a new version being commissioned just five days before the D-Day landings in June 1944. By the end of the Second World War, no fewer than ten Colossus machines were working at Bletchley Park.

The importance of Colossus was not recognised for many years, as all who worked on it were sworn to secrecy and all the machines were destroyed at the end of the war. It is now recognised as the world’s first electronic digital fixed-program computer.

Science Museum

Decade
Type
Computing,
Region
Midlands
Location
Bletchley Park, Milton Keynes
Key Individuals
Dollis Hill, Tommy Flowers, Bletchley Park,