The Special Fish Report
Albert W. Small (December 1944)
Codes and Ciphers
A technique has been developed using scanning, image inversion, Optical Character Reading, and translation into HTML format, which attempts to display each page as closely to the original as possible, respecting the idiosyncratic use of spaces and punctuation by the author. However because different browsers interpret HTML code differently, this cannot be achieved with real consistency.
The representation of the mathematical and technical symbols is also only offered in a preliminary version. As an illustration of the problems encountered, one has to distinguish x as a 'cross' in ciphertext, x as a 'score' measuring excess of dots or crosses, capital X as a sum of scores, and the Greek Chi character referring to the Chi-wheels of the Lorenz machine. An additional difficulty with HTML is that not all browsers support the Greek alphabet. As a temporary solution, a text representation has been adopted, as explained on the "Current Notations" page at the end of the document. The results are not entirely satisfactory and it is intended to go on to a second stage of editing in which subscripts, superscripts and Greek letters are more properly represented.
A further problem is that pages 30-54 and 85-92 are work sheets, some of which are A3 size. For the time being these have been omitted. It is hoped to add these when a suitable method has been found for displaying them.
The OCR technique has required an enormous amount of editing to clear up mis-read characters. I am indebted to Frode Weierud and many others for help in proof-reading. Reporting of any remaining "garbles" would be greatly appreciated.
For all the above reasons, anyone conducting research into this material should obtain their own copy of the original document, and not rely on this webpage version for quotation or citation.
However, despite all these deficiencies, it has seemed important and worthwhile to place this 'overview' version of the document on the Web. It gives a unique insight into the work of Bletchley Park at the height of its powers, as well as a fascinating reflection on Anglo-American relations.
Above all, this arduous task has been undertaken because of
the interest in Colossus and the need to fully understand and debate the wartime use of Colossus to
enable the completion of the Colossus Rebuild Project under the direction of
Breaking Key from Anagramming
Breaking Motor Wheels
Characteristics of D
Characteristics of Delta-D
Colossus Key Control Board
Key Breaking on Colossus
Machines Used in Newmanry
Messages in Depth
Motor and Psi Runs
Other Aids to Key Solution
Psi Breaking by Hand
Setting PSI's by Hand
The Tunny Machine
Appendix: Current Notations
Back to the index page for Tony Sale's Codes and Ciphers in the Second World War.
|This page was originally created by the late Tony Sale, the original curator of the Bletchley Park Museum, and Secretary of the Bletchley Park Heritage Society.||Technical assistance from Andrew Hodges|