Colossus

Bletchley Park Museum : Lorenz Cipher Machine
Descriptions of the Lorenz cipher machine and the Colossus computer built to crack the code. Information on the rebuild of a working Colossus.
http://www.codesandciphers.org.uk/lorenz/index.htm

Colossus at Bletchley Park
History and photos.
http://www.picotech.com/applications/colossus.html

How a Computer saved the world
Article from the American Computer Science Association about the history of Colossus (and IBM's involvement in WWII).
http://www.acsa.net/a_computer_saved_the_world.htm

IEEE Computer Society: Colossus
Brief description and photos.
http://www.computer.org/history/development/1940-44.htm

Nationmaster Encyclopedia: Colossus computer
The purpose, origins, and design of the world's first programmable digital electronic computer.
http://www.nationmaster.com/encyclopedia/Colossus-computer

Take a Tour of Bletchley Park
Information and photos on the Colossus rebuild project at Bletchley Park.
http://www.lightstraw.co.uk/bletchley/tour.html