An amazing book that pulls apart one of the strangest historical blind spots: that some of the world’s first programmable electronic computers weren’t built in Silicon Valley mythology, but in wartime secrecy at Bletchley Park.

The book traces the development of Colossus—designed to break the Lorenz cipher used by the German High Command—through a mix of technical reconstruction and newly declassified material, showing how engineers, mathematicians, and operators effectively invented modern computing under conditions where almost everything had to be destroyed or forgotten after the war. It’s part intellectual history, part forensic recovery—less about nostalgia, more about how an entire origin story was buried by design.

This is the 2006 Oxford University Press hardback edition, in very good condition with a clean interior and a well-kept dust jacket showing only light surface wear.