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Events on Thursday 1 June 1944 1
1944Colossus Mark 2 enters serviceImproved codebreaking computer at Bletchley ParkThe Colossus Mark 2, an electronic codebreaking machine designed by Tommy Flowers, went into service at Bletchley Park. It helped break the German Lorenz cipher used by the high command. Its intelligence confirmed that Hitler had been deceived about the Normandy landing site.