The National Museum of Computing

The National Museum of Computing stands on Bletchley Park in Milton Keynes. It occupies Block H, the first purpose-built computer centre in the world. Six of the ten wartime Colossus machines once worked here. The museum opened in 2007 and holds the world’s largest collection of working historic computers. It is a separate charity and runs its own café and shop. Volunteers maintain many machines in working order. The exhibits tell the story of British computing from the 1940s to the 1970s. A working replica of the Bombe shows how Enigma messages were broken. The Colossus gallery displays a five-tonne rebuild of the first large-scale electronic computer. The Tunny gallery shows the Lorenz cipher machine and its British emulator. The First Generation Gallery features a nearly finished replica of EDSAC, the first practical stored-program computer. Visitors follow a chronological route through several galleries. The Bombe Gallery explains Alan Turing’s role and Gordon Welchman’s improvements. The Colossus Gallery lets people watch the machine’s valves light up as it processes paper tape at 5,000 characters per second. The First Generation Gallery includes three large valve computers and many smaller artefacts. The museum’s own volunteers operate and explain the machines daily.