Page 19 Astor on consultations with the Twenty Committee: author’s interview with Hugh Astor.
Page 20 Montagu quotes: Ewen Montagu, The XX System (PRO ADM 223/794).
Page 21 Knox solution of Abwehr Enigma: Denniston to Menzies, minute, 10 December 1941 (PRO HW14). Lever solution of GGG machine: private information.
Page 22 Robertson quotes: Howard, British Intelligence, 5: 20–1.
Page 23 Philby quotes: West and Tsarev, The Crown Jewels, p. 309.
Page 24 Montagu quotes: Report entitled ‘ISOS’, 25 September 1945, 2–3.
Pages 25–61 Garbo and ISBA reports bring situation to a head: The Security Service 1908–1945, pp. 207–11; F. H. Hinsley and C. A. G. Simkins, British Intelligence in the Second World War: Volume 4 Security and Counter-Intelligence (HMSO, London, 1990), 4: 125–7; Howard, British Intelligence, 5: 19.
Page 26 A few weeks later: The Security Service 1908–1945, pp. 206–9.
Page 27 Petrie takeover bid for Section V and Menzies compromise: Michael Smith, Foley: The Spy Who Saved 10,000 Jews (Hodder & Stoughton, London, 1999), pp. 242–3.
Page 28 Masterman quotes: Masterman, The Double Cross System, p. 65,
Page 29 Problems of accepting that German perception different from that of the British: PRO DEFE 28/49.
Page 30 Quotes on improvements in MI5–MI6 liaison following Foley appointment: Smith, Foley, pp. 243–4.
Page 31–63 Details of Mincemeat: PRO ADM 223/794; Currer-Briggs quotes: Smith, Station X, pp. 121–2.
Page 32 Astor on ‘impression of tremendous rivalry’: author’s interview with Hugh Astor.
Page 33 Radio Security Intelligence Conference: Report entitled ‘ISOS’, 6.
Page 34 Astor on relations between MI5 and MI6 and use of Ultra: author’s interview with Hugh Astor.
Page 35 Bodyguard: Roger Hesketh, Fortitude: The D-Day Deception Campaign (St Ermin’s Press, London, 1999), pp. 17–19.
Page 36 Number of double agents: ibid., p. 46.
Page 37 Evolution of Fortitude: ibid., pp. 25–7.
Page 38 Main agents: ibid., pp. 46–56.
Page 39 Treasure comes close to giving away Fortitude: Summary of Treasure Case (PRO KV 2/464).
Page 40 Treasure ‘saves Bletchley’s bacon’: Page to Masterman and Masterman memo, both 29 November 1944, Summary of Treasure Case (ibid.).
Page 41 Garbo networks: Howard, British Intelligence, 5: 231–3.
Page 42 mobile wireless vehicles: Operation Neptune Radio Deception (PRO WO 208/5050), 2; Notes on Army Wireless Deception for Operation Overlord (ibid.), 2.
Page 43 Garbo message and shown to Hitler: Howard, British Intelligence, 5:188.
Page 44 Garbo reports and German acceptance of them: ibid., pp. 188–9.
Page 45 Interrogation of relieved German: Hesketh, Fortitude, pp. 489–90.
CHAPTER 17 HOW DILLY KNOX AND HIS GIRLS BROKE THE ABWEHR ENIGMA
Keith Batey has sadly passed away since writing this chapter. He died on 28 August 2010, aged 91.
Obituaries: The Daily Telegraph 2 September 2010; The Times, 10 September 2010; Scotsman, 6 September 2010
— http://www.thetimes.co.uk/tto/opinion/
obituaries/article2720655.ece
— http://www.telegraph.co.uk/news/obituaries/
military-obituaries/special-forces-obituaries/
7978325/Keith-Batey.html
— http://news.scotsman.com/obituaries/
Obituary-Keith-Batey-Mathematician-
and.6514032.jp?articlepage=1
Page 1 His note, dated 28 October: PRO HW 14/21.
Page 2 the abomination of desolation: Daniel 12: 11; Matthew 24: 15.
Page 3 Denniston’s reply: PRO HW 14/22.
CHAPTER 18 BREAKING TUNNY AND THE BIRTH OF COLOSSUS
Shaun Wylie has sadly passed away since writing this chapter. He died on 2 October 2009, aged 96.
Obituaries: The Guardian, 27 October 2009, The Daily Telegraph, 20 October 2009; Scotsman, 24 October 2009; The Times, 5 November 2009
— http://www.guardian.co.uk/education/
2009/oct/27/shaun-wylie-obituary
— http://www.telegraph.co.uk/news/
6389667/Shaun-Wylie.html
— http://news.scotsman.com/obituaries/
Shaun-Wylie-academic-and-code. 5762984.jp
— http://www.timesonline.co.uk/tol/
comment/obituaries/article6903467.ece
Page 1 Thrasher: Thrasher appears to have been the Siemens and Halske T43 teleprinter cipher machine, which employed a one-time tape.
Page 2 Sturgeon: The GC&CS attack against Sturgeon is fully described by Frode Weierud, ‘Sturgeon, The FISH BP Never Really Caught’, in David Joyner (ed.), Coding Theory and Cryptology: From Enigma and Geheimschreiber to Quantum Theory (Springer Verlag, New York, 1999), p. 18; Frode Weierud, ‘BP’s Sturgeon, The FISH that Laid No Eggs’, in B. Jack Copeland et al, Colossus: The Secrets of Bletchley Park’s Codebreaking Computers (OUP, Oxford, 2010).
Page 3 Mrs Miles: ‘General Report on Tunny, With Emphasis on Statistical Methods’, 369 (PRO HW 25/4). Mrs Miles of Eynesbury had quadruplets in 1935 at St Neots (http://www.sntc.co.uk/history.htm).
CHAPTER 19 COLOSSUS AND THE DAWNING OF THE COMPUTER AGE
The author is indebted to Diane Proudfoot for her detailed and valuable comments. More detail on this subject can be found in B. Jack Copeland et al, Colossus: The Secrets of Bletchley Park’s Codebreaking Computers (OUP, Oxford, 2010).
Page 1 ‘band of brothers’: A.W. Coombs, ‘The Making of Colossus’, Annals of the History of Computing, 5 (1983), 259.
Page 2 ‘eyes dropped out’: unless indicated otherwise all material directly relating to Flowers derives from (1) Flowers in interviews with Copeland, 1996–98; (2) Flowers in interview with Christopher Evans in 1976 (‘The Pioneers of Computing: an Oral History of Computing’, Science Museum, London).
Page 3 February 1944: ‘General Report on Tunny, With Emphasis on Statistical Methods’ (PRO HW 25/4, 25/5). Much of the detailed information in this chapter concerning Tunny and Bletchley’s attack on Tunny comes from this report, which except in the case of direct quotation will not be referenced again. A digital facsimile of the typescript available in The Turing Archive for the History of Computing at
Page 4 taken to Newman’s newly created Computing Machine Laboratory: K. Myers, ‘Dollis Hill and Station X’, in B. J. Copeland (ed.), Colossus: The First Computer (OUP, Oxford, 2006).
Page 5 1960: Donald Michie, personal communication, 2000. The author is indebted to Michie for a number of conversations about Colossus, Tunny and the Newmanry.
Page 6 photographs of Colossus (PRO FO 850/234).
Page 7 outlines of Colossus: I. J. Good, ‘Some Future Social Repercussions of Computers’, International Journal of Environmental Studies, 1 (1970), 67; I. J. Good, ‘Early Work on Computers at Bletchley’, Annals of the History of Computing, 1 (1979), 38; D. Michie, ‘The Bletchley Machines’, in B. Randell (ed.), The Origins of Digital Computers: Selected Papers (Springer-Verlag, Berlin, 1973); B. Randell, ‘The Colossus’, in N. Metropolis, J. Howlett and G. C. Rota (eds), A History of Computing in the Twentieth Century (Academic Press, New York, 1980).
Page 8 hardware of Colossus I: T. H. Flowers, ‘The Design of Colossus’, Annals of the History of Computing, 5 (1983), 239.
Page 9 ‘disciplined but unintelligent manner’: A. M. Turing, ‘Programmers’ Handbook for Manchester Electronic Computer’ (University of Manchester Computing Laboratory, 1950), 1. A digital facsimile is available at
Page 10 Lovelace envisaged: A. A. Lovelace and L. F. Menabrea, ‘Sketch of the Analytical Engine Invented by Charles Babbage, Esq.’ (1843), in B. V. Bowden (ed.). Faster than Thought (Pitman, London, 1953).
Page 11 Difference Engine: C. Babbage, Passages from the Life of a Philosopher, M. Campbell-Kelly (
ed.), The Works of Charles Babbage, vol. 11 (William Pickering, London, 1989); B. Randell (ed.), The Origins of Digital Computers: Selected Papers (Springer-Verlag, Berlin, 1982 – 3rd edn.), chap. 1.
Page 12 Analytical Engine: Babbage, op. cit.; Lovelace and Menabrea, op. cit.; Randell, op. cit., chap. 2; A. Bromley, ‘Charles Babbage’s Analytical Engine, 1838’, Annals of the History of Computing, 4 (1982), 196.
Page 13 Vannevar Bush and Howard Aiken: V. Bush, ‘Instrumental Analysis’, Bulletin of the American Mathematical Society, 42 (1936), 649 (the text of the 1936 Josiah Willard Gibbs Lecture); H. Aiken, ‘Proposed Automatic Calculating Machine’, in Randell, op. cit.
Page 14 mealtime discussion at Bletchley: Flowers in interview with Copeland, 1996.
Page 15 ENIAC: A. W. Burks, ‘From ENIAC to the Stored-Program Computer: Two Revolutions in Computers’, in Metropolis, Howlett and Rota, op. cit.; H. H. Goldstine, The Computer from Pascal to von Neumann (Princeton University Press, Princeton, 1972); H. H. Goldstine and A. Goldstine, 1946, ‘The Electronic Numerical Integrator and Computer’, in Randell, op. cit.
Page 16 given by Newman: Newman in interview with Christopher Evans in 1976 (The Pioneers of Computing’).
Page 17 ‘all numbers which could …’: A. M. Turing, ‘On Computable Numbers, with an Application to the Entscheidungsproblem’, Proceedings of the London Mathematical Society, Series 2, 42 (1936–37), 230.
Page 18 emphasized that the Analytical Engine was universal: A. M. Turing, ‘Computing Machinery and Intelligence’, Mind, 59 (1950), 433.
Page 19 works on both using exactly the same operations: this is emphasized by Robin Candy in his ‘The Confluence of Ideas in 1936’, in R. Herken (ed.), The Universal Turing Machine: A Half-Century Survey (OUP, Oxford, 1998).
Page 20 later to suggest: A. M. Turing, ‘Lecture to the London Mathematical Society on 20 February 1947’, in B. E. Carpenter and R. W. Doran (eds), A. M. Turing’s ACE Report of 1946 and Other Papers (MIT Press, Cambridge, Mass., 1986).
Page 21 Right from the start: Newman in interview with Evans, op. cit.
Page 22 Differential Analyser: V. Bush, ‘The Differential Analyser: A New Machine for Solving Differential Equations’, Journal of the Franklin Institute, 212 (1931), 447; V. Bush, ‘Instrumental Analysis’, Bulletin of the American Mathematical Society, 42 (1936), 649; V. Bush, S. H. Caldwell, ‘A New Type of Differential Analyser’, Journal of the Franklin Institute, 240 (1945), 255.
Page 23 joined the Telephone Branch of the Post Office: ‘Mr T. H. Flowers, MBE, BSc, MIEE’, Post Office Electrical Engineers Journal (October 1950), 156.
Page 24 pay occasional visits to the London office: letter from Peter Twinn to Copeland, 2001.
Page 25 at the British Tabulating Machine Company: ‘Enigma-Position’ and ‘Naval Enigma Situation’, two notes, 1 November 1939, by Knox, Twinn, Welchman and Turing (PRO HW 14/2).
Page 26 Fellow since 1923: W. Newman, ‘Max Newman: Mathematician, Codebreaker and Computer Pioneer’, in Copeland et al, Colossus.
Page 27 letters about mathematical logic: there are five letters from Turing to Newman during this period in the Modern Archive Centre, King’s College Library, Cambridge.
Page 28 academic paper, published in March 1942: M. H. A. Newman, A. M. Turing, ‘A Formal Theorem in Church’s Theory of Types’, Journal of Symbolic Logic, 7 (1942), 28.
Page 29 wrote to the Master of St John’s: W. Newman, op. cit.
Page 30 William Tutte made the crucial break: W. T. Tutte, ‘At Bletchley Park’, in Copeland et al, Colossus.
Page 31–15 rest of the Research Section joined in: ibid.
Page 32 designed by C. E. Wynn-Williams: C. E. Wynn-Williams, ‘A Thyratron Scale of Two Automatic Counter’, Proceedings of the Royal Society of London, series A, 136 (1932), 312.
Page 33 ‘other people’s problems’: Newman in interview with Evans, op. cit.
Page 34 Construction started in January 1943: the following paragraphs are indebted to accounts by three Dollis Hill engineers involved with Heath Robinson and Colossus, H. Fensom, ‘How the Codebreaking Colossus was Conceived, Built and Operated: One of its Engineers Reveals its Secrets’, K. Myers, ‘Wartime Memories of Dollis Hill and Bletchley Park’, and N. T. Thurlow, ‘The Road to Colossus’, all in Copeland (ed.), Colossus: The First Computer.
Page 35 Dollis Hill made: letter from Harry Fensom to Copeland, 2001.
Page 36 ‘a knowledge of…’: ‘General Report on Tunny’, 22.
Page 37 considered the offer derisory: Peter Hilton in interview with Copeland, 2001. The author is indebted to Hilton for numerous conversations about Bletchley Park; also to P. Hilton, ‘Living With Fish: Breaking Tunny in the Newmanry and the Testery’, in Copeland et al, Colossus.
Page 38 ‘didn’t really understand …’: Flowers in interview with Copeland, 1996.
Page 39 ‘got out’; ‘in close touch with Turing’: letter from Newman to von Neumann, 8 February 1946. A digital facsimile of the letter is available at
archive/p/p01/P01-001.html>.
Page 40 During the remainder of 1945: Michael Woodger in interview with Copeland, 1998. According to Woodger (Turing’s assistant at the NPL from May 1946), an NPL file gave the date of Turing’s technical report as 1945. Unfortunately, this file has since been destroyed. Woodger believes that Turing probably wrote the document between October and December 1945.
Page 41 ‘Proposed Electronic Calculator’: reprinted in full under the title ‘Proposal for Development in the Mathematics Division of an Automatic Computing Engine (ACE)’, in Carpenter and Doran (eds), A. M. Turing’s ACE Report of 1946 and Other Papers. A digital facsimile of the original typescript is available at
Page 42 ‘First Draft of a Report on the EDVAC’: reprinted in full in N. Stern, From ENIAC to UNIVAC: An Appraisal of the Eckert-Mauchly Computers (Digital Press, Bedford, Mass., 1981).
Page 43 ‘one machine would suffice …’: C. Darwin, ‘Automatic Computing Engine (ACE)’, 17 April 1946. NPL document. A digital facsimile is available at
archive/p/p04/P04-001.html>.
Page 44 Bendix G15 computer: H. D. Huskey, ‘From ACE to the G15’, Annals of the History of Computing, 6 (1984), 350.
Page 45 other derivatives: D. Yates, Turing’s Legacy: A History of Computing at the National Physical Laboratory 1945–1995 (Science Museum, London, 1997).
Page 46 a ‘minimal ACE’ would be ready: ‘Status of the Delay Line Computing Machine at the P.O. Research Station’. 7 March, 1946. NPL document. A digital facsimile is available at http://www.alanturing.net/delay_line_status (accessed 5 November 2010).
Page 47 ‘too busy …’: Flowers in interview with Copeland, 1998.
Page 48 Turing suggested that the NPL: A. Turing, ‘Report on visit to U.S.A., January 1st – 20th, 1947’. 3 February 1947. NPL document. A digital facsimile is available at http://www.alanturing.net/turing_usa_visit (accessed 5 November 2010).
Page 49 ‘probably as far advanced 18 months ago’: NPL Executive Committee Minutes, 20 April 1948, 7. A digital facsimile is available at http://www. alanturing.net/npl_minutes_apr1948 (accessed 5 November 2010).
Page 50 pioneering work on Artificial Intelligence: A. M. Turing, ‘Intelligent Machinery’, National Physical Laboratory Report, [1948], Reprinted in full in B. Meltzer and D. Michie (eds), Machine Intelligence 5 (Edinburgh University Press, Edinburgh, 1969). A digital facsimile of the report is available at http://www.alanturing.net/intelligence_machinery (accessed 5 November 2010). See also B. J. Copeland and D. Proudfoot, ‘Alan Turing’s Forgotten Ide
as in Computer Science’, Scientific American, 280 (April 1999), 76.
Page 51 ‘very fed up’: Robin Candy’s description of Turing in interview with Copeland, 1995.
Page 52 approved by the Treasury in May 1946: Council Minutes, Royal Society, 1946. Turing’s salary was paid wholly from Newman’s grant; letter from Newman to D. Brunt, 22 December 1948.
Page 53 ‘It was one room in a Victorian building …’: F. C. Williams, ‘Early Computers at Manchester University’, The Radio and Electronic Engineer, 45 (1975), 237.
Page 54 he designed: letter from Williams to Randell, printed in B. Randell, ‘On Alan Turing and the Origins of Digital Computers’, in Meltzer and Michie (eds), Machine Intelligence, 9.
Page 55 programming manual: ‘Programmers’ Handbook for Manchester Electronic Computer’.
Page 56 Artificial Life: A. M. Turing, ‘The Chemical Basis of Morphogenesis’, Philosophical Transactions of the Royal Society of London, series B, 237 (1952), 37.
Page 57 programming digital computers to think: A. M. Turing, ‘Computing Machinery and Intelligence’, Mind, 59 (1950), 433.
Page 58 perhaps given too little credit: Peter Hilton in interview with Copeland, 2001.
Page 59 ‘… Newman explained the whole business …’: Williams in interview with Christopher Evans in 1976 (‘The Pioneers of Computing’). See further B. J. Copeland (ed.), ‘A Lecture and Two Radio Broadcasts on Machine Intelligence by Alan Turing’, in K. Furukawa, D. Michie and S. Muggleton (eds), Machine Intelligence 15 (OUP, Oxford, 1999).
Page 60 ‘number of different computing projects …’: Turing, ‘Report on visit to U.S.A., January 1st – 20th, 1947’.
Page 61 contract with the US Army Ordnance Department: Goldstine, op. cit., 150.
Page 62 consultant to the Eckert-Mauchly project: John Mauchly recalled that 7 September 1944 ‘was the first day that von Neumann had security clearance to see the ENIAC and talk with Eckert and me’ (J. Mauchly, ‘Amending the ENIAC Story’, Datamation, 25(11) (1979), 217). Goldstine (op. cit., 185) suggests that the date of von Neumann’s first visit may have been a month earlier: ‘I probably took von Neumann for a first visit to the ENIAC on or about 7 August’.
The Bletchley Park Codebreakers Page 55