One of the set of 129 photographs of the Government Code and Cypher School at Bletchley Park. This one shows punch card processing machinery as used for the Central Index.
Good, Jack; Michie, Donald; Timms, Geoffrey (1945), General Report on Tunny: With Emphasis on Statistical Methods, UK Public Record Office HW 25/4 and HW 25/5
2014-03-30 17:57:32
UK Government Public Domain