The Turing Digital Archive contains nearly 3,000 images of letters, photographs, newspaper articles, and unpublished papers by or about Alan Turing. The images were scanned from the collection of Turing papers held in the Archive Centre at King's College, Cambridge. The images are subject to copyright restrictions.

For an insight into Alan Turing's life and works, along with highlights of BBC programmes shown during Turing's centenary year see:

• BBC History: Alan Turing
• BBC commissioned series on Alan Turing

For further information about code breaking during World War II see:

• BBC History: Code Breaking

The Enigma and the Bombe http://www.ellsbury.com/enigmabombe.htm

Alan Turing http://en.wikipedia.org/wiki/Alan_Turing

Solving the Enigma: History of the Cryptanalytic Bombe http://www.nsa.gov/about/_files/cryptologic_heritage/publications/wwii/solving_enigma.pdf

Enigma Cipher Machine http://www.cryptomuseum.com/crypto/enigma/

Turing at NPL http://www.npl.co.uk/about/history/notable-individuals/turing/

The Guardian features articles, commentaries and blog posts on Turing's life, works and legacy.

The site makes available online digital facsimiles of key primary texts in the history of computing, with special reference to the pioneering work of Alan Turing.

Historic site of secret British codebreaking activities during WWII and birthplace of the modern computer.