The Manchester computer: A revised history part 1: The memory

IEEE Annals of the History of Computing

Volumn 33, Issue 1, 2011, Pages 4-21

  Copeland, B Jack ^a  

^a UNIVERSITY OF CANTERBURY   (New Zealand)

Author keywords

A.M. Turing; Automatic Computing Engine (ACE); Bletchley Park; cathode ray tube memory; Colossus; F.C. Williams.; I.J. Good; J. von Neumann; J.P. Eckert; M.H.A. Newman; Manchester Baby computer; Manchester Mark I Computer; Moore School; Princeton Computer; R.A. McConnell; Royal Society Computing Machine Laboratory; Small Scale Experimental Machine (SSEM); T. Kilburn; Telecommunications Research Establishment (TRE); Turing Wilkinson Lecture Series; Williams tube

Indexed keywords

A.M. TURING; AUTOMATIC COMPUTING ENGINE (ACE); BLETCHLEY PARK; CATHODE-RAY TUBE MEMORY; COLOSSUS; I.J. GOOD; J. VON NEUMANN; J.P. ECKERT; M.H.A. NEWMAN; MANCHESTER; MOORE SCHOOL; PRINCETON COMPUTER; R.A. MCCONNELL; ROYAL SOCIETY; SMALL-SCALE EXPERIMENTAL MACHINE (SSEM); T. KILBURN; WILKINSON; WILLIAMS;

CATHODES; COMPUTERS; PARKS;

TUBES (COMPONENTS);

EID: 79952428470     PISSN: 10586180     EISSN: None     Source Type: Journal    
DOI: 10.1109/MAHC.2010.1     Document Type: Review

References (154)

1. F. C. Williams and T. Kilburn, "Electronic Digital Computers, " Nature, vol. 162, no. 4117, 1948, p. 487. The letter is dated 3 August 1948.
2. See M. Croarken, Early Scientific Computing in Britain, Oxford Univ. Press, 1990;
3. S. H. Lavington, A History of Manchester Computers, NCC Publications, 1975;
4. S. H. Lavington, A History of Manchester Computers, 2nd ed., British Computer Soc., 1998;
5. S. H. Lavington, Early British Computers: The Story of Vintage Computers and the People Who Built Them, Manchester Univ. Press, 1980;
6. M. Wilkes and H. J. Kahn, "Tom Kilburn CBE FREng, " Biographical Memoirs of Fellows of the Royal Society, vol. 49, 2003, pp. 285-297. In my "Colossus and the Dawning of the Computer Age" (in R. Erskine and M. Smith eds., Action This Day, Bantam Books, 2001) I pointed out that "During the official celebrations of the fiftieth anniversary of the Baby, held at Manchester in June 1998, Newman's name was not so much as mentioned" (p. 366). I argued that, in the light of Newman's achievements at Bletchley Park, "the history of computing must be rewritten" (p. 369), and I explained how "Newman had played a crucial role indeed in the triumph at Manchester" (p. 366). I concluded that "Histories written in ignorance of Colossus are not only incomplete, but give a distorted picture of the emergence and development of the idea of the modern computer. Turing's logical work in 1935-1936 and Flowers' work at Bletchley led, via Newman's desire to put the concept of the stored-program universal computing machine into practice, to the Manchester Computing Machine Laboratory and the Manchester Mark I computer" (p. 369).
7. Lavington, A History of Manchester Computers, 2nd ed., p. 8.
8. I am grateful to several Manchester historians for information and discussion concerning this view of events, in particular Chris Burton (director of the Manchester Baby Rebuild Project) for his comments during the Q&A part of my 2000 lecture at the National Physical Laboratory, London, on the early history of British electronic computing; Brian Napper for his comments at the Royal United Services Institute for Defence in Whitehall, London, during the Q&A part of my 2001 lecture on Colossus and the origins of the Manchester computer; Hilary Kahn for her comments during the Q&A part of my 2004 lecture at the University of Manchester on Bletchley Park and the Manchester computer; and Dai Edwards, to whom I am grateful for sending me his essay "Two Computer Projects." David Anderson critiques the twoproject theory in his "Was the Manchester Baby Conceived at Bletchley Park?" Univ. of Portsmouth Research Report number UoP-HC-2006-001, 2006, http://www.tech.port.ac.uk/staffweb/andersod/HoC, and in modified form on the British Computer Society's website in 2009 (http://www.bcs.org/server.php?show= ConWebDoc.17134).
9. Lavington, Early British Computers, p. 24.
10. Lavington, Early British Computers, p. 23.
11. T. Kilburn, "A Storage System for use with Binary Digital Computing Machines, " report for TRE, 1 Dec. 1947, Nat'l Archive for the History of Computing, Univ. of Manchester. (A retyped version, complete with editorial notes by Brian Napper, is at http://www.computer50.org/kgill/mark1/report1947. html.)
12. T. Kilburn "The University of Manchester Universal High-Speed Digital Computing Machine, " Nature, vol. 164, no. 4173, 1949, pp. 684-687.
13. T. Kilburn, interview by B. J. Copeland, July 1997.
14. M. Croarken, "The Beginnings of the Manchester Computer Phenomenon: People and Influences, " IEEE Annals of the History of Computing, vol. 15, no. 3, 1993, pp. 9-16. The quotations are from p. 9.
15. Croarken, Early Scientific Computing in Britain, p. 123.
16. Huskey's 1947 report is published in B. J. Copeland, ed., Alan Turing's Automatic Computing Engine, Oxford Univ. Press, 2005.
17. Especially the section on Newman in B. J. Copeland, "A Lecture and Two Radio Broadcasts on Machine Intelligence by Alan Turing, " Machine Intelligence 15, K. Furukawa, D. Michie, and S. Muggleton, eds., Oxford Univ. Press, 1999, pp. 445-476 (see pp. 454-457, where I argue that "the major credit for the Manchester machine belongs not only to Williams and Kilburn but also to Newman");
18. and B. J. Copeland, "Colossus and the Dawning of the Computer Age, " Action This Day, R. Erskine and M. Smith, eds., Bantam Books, 2001.
19. See also B. J. Copeland, "Modern History of Computing, " The Stanford Encyclopedia of Philosophy, E. Zalta, ed., 2001, http://plato.stanford. edu;
20. B. J. Copeland, ed., The Essential Turing, Oxford Univ. Press, 2004, chaps. 5 and 9;
21. Copeland, ed., Alan Turing's Automatic Computing Engine, chap. 5 and Introduction;
22. and B. J. Copeland et al., Colossus: The Secrets of Bletchley Park's Codebreaking Computers, Oxford Univ. Press, 2006, chap. 9. My research on Newman, Bletchley Park, and the origins of the Manchester computer has been disseminated in numerous public lectures, including those mentioned in note 4, and at Bletchley Park (2001, 2002, 2004, and 2007), Portsmouth University (2002), the Royal Institution of London (2004), Government Communications Headquarters (GCHQ, 2004), and the Science Museum, London (2004).
23. F. C. Williams, interview by C. Evans, "The Pioneers of Computing: An Oral History of Computing, " Science Museum, 1976 (copyright of Board of Trustees of the Science Museum). This interview was supplied to me on audiotape in 1995 by the archives of the London Science Museum (and transcribed by me in 1997). I am grateful to the Science Museum for permission to quote from the tape recording here.
24. A. M. Turing to M. Woodger, undated, received 12 Feb. 1951, Woodger Papers, Science Museum, Kensington, London. Also available in my and Diane Proudfoot's online archive, "The Turing Archive for the History of Computing, " http://www.AlanTuring.net/turing-woodger-feb51.
25. This fact was first publicized by Lavington in his A History of Manchester Computers, p. 20, although the date of the first UNIVAC is given there as June 1951.
26. M. Campbell-Kelly provides an excellent account of the Mark I (together with biographical information on Newman, Williams, Kilburn, and other Manchester figures) in "Programming the Mark I: Early Programming Activity at the University of Manchester, " Annals of the History of Computing, vol. 2, no. 2, 1980, pp. 130-168.
27. N. Stern, "The BINAC: A Case Study in the History of Technology, " Annals of the History of Computing, vol. 1, no. 1, 1979, p. 17;
28. N. Stern, From ENIAC to UNIVAC: An Appraisal of the Eckert-Mauchly Computers, Digital, 1981, p. 149.
29. Wilkes and Kahn, "Tom Kilburn CBE FREng, " p. 286.
30. A. P. Rowe's first-hand history of TRE is highly informative: One Story of Radar, Cambridge Univ. Press, 1948.
31. The definitive biographical article on Newman is "Max Newman-Mathematician, Codebreaker, and Computer Pioneer, " by his son William, in B. J. Copeland, Colossus: The Secrets of Bletchley Park's Codebreaking Computers, chap. 14. This volume contains much additional information about Newman, especially in chaps. 4, 5, and 9 and in chap. 13 (entitled "Mr Newman's Section") written by myself and five of Newman's wartime engineers and computer operators.
32. See also the biographical material on Newman in my chapter, "A Lecture and Two Radio Broadcasts on Machine Intelligence by Alan Turing, " pp. 454-457. A brief biography of Newman recently
33. appeared in D. Anderson, "Max Newman: Topologist, Codebreaker, and Pioneer of Computing, " IEEE Annals of the History of Computing, vol. 29, no. 3, 2007, pp. 76-81.
34. A. M. Turing, "On Computable Numbers, with an Application to the Entscheidungsproblem, " Proc. London Mathematical Soc., series 2, vol. 42, 1936-1937, pp. 230-265;
35. reprinted in Copeland, ed., The Essential Turing.
36. B. Randell, "Colossus, " A History of Computing in the Twentieth Century, N. Metropolis, J. Howlett, and G. C. Rota, eds., Academic Press, 1980;
37. B. J. Copeland, "Colossus: Its Origins and Originators, " IEEE Annals of the History of Computing, vol. 26, no. 4, 2004, pp. 38-45.
38. I. J. Good to C. Ghersie, 20 Nov. 1970, in I. J. Good, "Early Notes on Electronic Computers, " compiled in 1972 and 1976, Nat'l Archive for the History of Computing, Univ. of Manchester, MUC/Series 2/a4.
39. T. H. Flowers, personal diary entry, 18 Jan. 1944.
40. This paragraph recapitulates the biographical information on Newman in Copeland, "Colossus: Its Origins and Originators." I am grateful to David Grier for his suggestion that I included therein biographies of the principal figures associated with Colossus, an approach I continue here.
41. Copeland, ed., The Essential Turing, chaps. 5 and 6.
42. A. M. Turing, "Proposed Electronic Calculator, " in B. J. Copeland, ed., Alan Turing's Automatic Computing Engine, Oxford Univ. Press, 2005.
43. H. D. Huskey to B. J. Copeland, 4 Feb. 2002.
44. Copeland, ed., Alan Turing's Automatic Computing Engine, chap. 3.
45. M. Woodger, interview by B. J. Copeland, June 1998.
46. S. Ulam, "John von Neumann 1903-1957, " Am. Mathematical Soc. Bulletin, vol. 64, no. 3, pt. 2, 1958, p. 3.
47. J. von Neumann to O. Veblen, 21 May 1943;
48. quoted by W. Aspray, John von Neumann and the Origins of Modern Computing, MIT Press, 1990, p. xv.
49. John Mauchly recalled that 7 Sept. 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, vol. 25, no. 11, 1979, p. 217.) Goldstine suggests that the date of von Neumann's first visit might have been a month earlier: "I probably took von Neumann for a first visit to the ENIAC on or about 7 August"
50. (H. H. Goldstine, The Computer from Pascal to von Neumann, Princeton Univ. Press, 1972, p. 185).
51. N. Stern, "John von Neumann's Influence on Electronic Digital Computing, 1944-1946, " Annals of the History of Computing, vol. 2, no. 4, 1980, p. 354.
52. Copeland, ed., The Essential Turing, pp. 21-27.
53. J. Bigelow to B. J. Copeland, 12 Apr. 2002.
54. See also Aspray, John von Neumann and the Origins of Modern Computing, p. 178.
55. T. Kilburn and L. S. Piggot, "Frederic Calland Williams, " Biographical Memoirs of Fellows of the Royal Soc., vol. 24, 1978, p. 584.
56. F. C. Williams, interview by C. Evans, B. Lovell, "Patrick Maynard Stuart Blackett, Baron Blackett, of Chelsea, " Biographical Memoirs of Fellows of the Royal Soc., vol. 21, 1975, pp. 47-48.
57. Kilburn and Piggot, "Frederic Calland Williams, " pp. 584-590.
58. Kilburn and Piggot, "Frederic Calland Williams, " p. 591.
59. F. C. Williams, interview by C. Evans, transcription by B. J. Copeland, 1997.
60. This section summarizes research reported in those of my publications listed in note 12, especially Copeland, "A Lecture and Two Radio Broadcasts on Machine Intelligence by Alan Turing, " and Copeland, "Colossus and the Dawning of the Computer Age."
61. T. H. Flowers, interview by B. J. Copeland, July 1996.
62. M. H. A. Newman to J. von Neumann, 8 February 1946, von Neumann Archive, Library of Congress, Washington, DC. Also available at http://www.AlanTuring. net/newman-vonneumann-8feb46.
63. M. H. A. Newman, interview by C. Evans, "The Pioneers of Computing: An Oral History of Computing, " Science Museum (copyright of Board of Trustees of the Science Museum). This interview was supplied to me on audiotape in 1995 by the archives of the London Science Museum (and transcribed by me in 1997). I am grateful to the Science Museum for permission to quote from the tape recording. These passages were published in 2004 in Copeland, ed., The Essential Turing, p. 206. (A different transcription of the first passage was printed in Annals in 2007 in Anderson, "Max Newman: Topologist, Codebreaker, and Pioneer of Computing, " p. 78.)
64. M. H. A. Newman, interview by C. Evans.
65. Nat'l Archives/Public Record Office, document reference FO 850/234. The photographs were declassified in 1975. Photographs and the accompanying caption were published in Randell, "Colossus, " 1980.
66. "General Report on Tunny, with Emphasis on Statistical Methods, " Nat'l Archives/Public Record Office, document reference HW 25/4, HW 25/5 (2 volumes). This report was written in 1945 by Jack Good, Donald Michie, and Geoffrey Timms (all members of Newman's section at Bletchley Park). Also available at http://www.AlanTuring.net/tunny-report.
67. J. von Neumann, "The NORC and Problems in High Speed Computing" (1954), Collected Works of John von Neumann, vol. 5, A. H. Taub, ed., Pergamon Press, 1961; the quote is from pp. 238-239.
68. M. V. Wilkes, Memoirs of a Computer Pioneer, MIT Press, 1985;
69. J. R. Womersley, "A. C. E. Project-Origin and Early History, " Nat'l Physical Lab., 26 Nov. 1946
70. in Copeland, ed., Alan Turing's Automatic Computing Engine, pp. 38-39, and also at http://www.AlanTuring. net/ace-early-history.
71. D. Michie to B. J. Copeland, 14 July 1995. (I am grateful to Michie for suggesting in 1995 that I document Newman's leading role in the Manchester computer project.)
72. GCHQ Official History, unpublished.
73. Council Minutes, Royal Soc. of London (13 Dec. 1945, 14 Feb. 1946, 7 Mar. 1946, 11 April 1946, 16 May 1946, 13 June 1946), Royal Soc. of London Archives.
74. Copeland, "Colossus and the Dawning of the Computer Age, " p. 344;
75. K. Myers, interview by B. J. Copeland, July 2001;
76. K. Myers, "Wartime memories of Dollis Hill and Bletchley Park (B/P or Station X), " typescript, n. d., c. 2000, p. 5.
77. I. J. Good to B. J. Copeland, 5 Mar. 2004.
78. "General Report on Tunny, with Emphasis on Statistical Methods;" Copeland, Colossus: The Secrets of Bletchley Park's Codebreaking Computers; Copeland "Colossus: Its Origins and Originators."
79. D. Michie, unpublished memoir sent to B. J. Copeland in Mar. 1997.
80. Copeland, "A Lecture and Two Radio Broadcasts on Machine Intelligence by Alan Turing, " pp. 455-457;
81. Copeland, "Colossus and the Dawning of the Computer Age, " pp. 365-366, 369.
82. "Report by Professor M. H. A. Newman on Progress of Computing Machine Project, " Appendix A, Council Minutes, Royal Soc. of London Archives, 13 Jan. 1949.
83. This terminology is also advocated by Lavington History of Manchester Computers, 2nd ed., p. 12.
84. F. C. Williams, quoted in S. Bennett, "F. C. Williams: His contribution to the development of automatic control, " unpublished typescript based on interviews with Williams in 1976, Nat'l Archive for the History of Computing, Univ. of Manchester.
85. D. Michie, interview by B. J. Copeland, Oct. 1995;
86. Copeland, "A Lecture and Two Radio Broadcasts on Machine Intelligence by Alan Turing, " p. 455, from which this paragraph is drawn. Much the same points are made in recent biographies of Newman and Blackett in Anderson, "Max Newman: Topologist, Codebreaker, and Pioneer of Computing;"
87. and D. Anderson, "Patrick Blackett: Physicist, Radical, and Chief Architect of the Manchester Computing Phenomenon, " IEEE Annals of the History of Computing, vol. 29, no. 3, 2007, pp. 82-85.
88. F. C. Williams quoted in Lovell, "Patrick Maynard Stuart Blackett, Baron Blackett, of Chelsea, " p. 48.
89. F. C. Williams, "Early Computers at Manchester University, " The Radio and Electronic Eng., vol. 45, 1975, p. 331.
90. Williams "Early Computers at Manchester University, " p. 328.
91. F. C. Williams quoted in Kilburn and Piggot, "Frederic Calland Williams, " p. 593.
92. H. J. Kahn to B. J. Copeland, 18 June 2007.
93. F. C. Williams, "A Cathode-Ray Tube Digit Store, " Proc. Royal Soc. of London, series A, vol. 195, 1948, p. 284.
94. T. Kilburn, "A Storage System for use with Binary Digital Computing Machines, " doctoral thesis, Univ. of Manchester, 1948, p. i.
95. Copeland et al., Colossus: The Secrets of Bletchley Park's Codebreaking Computers, pp. 301-302.
96. "General Report on Tunny, with Emphasis on Statistical Methods, " vol. 2, Nat'l Archives/Public Record Office, document reference HW 25/5, pp. 365-366. Also available at http://www.AlanTuring.net/tunny-report.
97. H. Fensom, "How Colossus was Built and Operated-One of its Engineers Reveals its Secrets, " Colossus: The Secrets of Bletchley Park's Codebreaking Computers, Copeland et al., pp. 301-302.
98. J. V. Atanasoff, "Computing Machine for the Solution of Large Systems of Linear Algebraic Equations" (1940), The Origins of Digital Computers: Selected Papers, 3rd ed., B. Randell, ed., Springer-Verlag, 1982.
99. Turing "Proposed Electronic Calculator, " p. 426. As well as discussing storage using an ordinary CRT, Turing also mentioned von Neumann's proposal for using the specialized iconoscope tube for storage.
100. Turing, "Proposed Electronic Calculator, " pp. 426-427.
101. R. A. McConnell, A. G. Emslie, and F. Cunningham, "A Moving Target Selector Using Deflection Modulation on a Storage Mosaic, " Radiation Lab., Massachusetts Inst. of Technology, Report 562, 6 Jun. 1944, p. 7.
102. See also R. A. McConnell, "Video Storage by Secondary Emission From Simple Mosaics, " Proc. I. R. E., vol. 35, 1947, pp. 1258-1264.
103. F. C. Williams and T. Kilburn, "A Storage System for use with Binary Digital Computing Machines, " Proc. Institution of Electrical Eng., vol. 96, 1949, pp. 81-100.
104. McConnell Emslie and Cunningham, "A Moving Target Selector Using Deflection Modulation on a Storage Mosaic, " p. 7.
105. R. A. McConnell, "The Storage of Video Signals on Simple Mosaics, " Radiation Lab., Massachusetts Inst. of Technology, Report 743, 18 Feb. 1946, p. 46.
106. No doubt Williams was shown the experiments by Britton Chance, general director of McConnell's work at the Radiation Laboratory. Williams was visiting Chance, with whom he was editing two volumes in the McGraw-Hill Radiation Laboratory Series.
107. J. von Neumann, "First Draft of a Report on the EDVAC, " Moore School of Electrical Eng., 30 June 1945, section 12.8 (reprinted in IEEE Annals of the History of Computing, vol. 15, no. 4, 1993, pp. 27-75).
108. N. Stern, ed., "Minutes of 1947 Patent Conference, Moore School of Electrical Engineering, University of Pennsylvania, " Annals of the History of Computing, vol. 7, no. 2, 1985, p. 108.
109. C. B. Sheppard, lecture 21, p. 268
110. M. Campbell-Kelly and M. R. Williams, eds., The Moore School Lectures, MIT Press, 1985. The date of Sheppard's report of Sharpless's work was 24 July 1946.
111. J. P. Eckert, lectures 10 (15 July) and 33 (6 August), and C. B. Sheppard, lectures 11 (15 July) and 21 (24 July).
112. Campbell-Kelly and Williams, eds., The Moore School Lectures.
113. J. P. Eckert, H. Lukoff, and G. Smoliar, "A Dynamically Regenerated Electrostatic Memory System, " Proc. I. R. E., vol. 38, 1950, p. 503.
114. C. B. Sheppard, lecture 11, p. 133.
115. Campbell-Kelly and Williams, eds., The Moore School Lectures.
116. Another investigation into tube storage began in 1946, at the RCA Laboratories in Princeton. There work started on the highly ambitious special-purpose digital storage tube called the Selectron. Progress was glacial. The Selectron did not become available until circa 1953 and was then soon discontinued by RCA. J. Bigelow, "Computer Development at the Institute for Advanced Study, " A History of Computing in the Twentieth Century, N. Metropolis, J. Howlett, and G. C. Rota, eds., Academic Press, 1980, p. 303;
117. W. H. Ware, "The History and Development of the Electronic Computer Project at the Institute for Advanced Study, " tech. report P-377, RAND, 10 Mar. 1953, p. 17;
118. Aspray, John von Neumann and the Origins of Modern Computing, pp. 79, 279-280;
119. "The RCA Selectron, " http://www.rcaselectron.com.
120. "Williams Cathode Ray Tube Storage: Evidence Relating to the Origin of the Invention and the Dissemination of Information on the Operation of the Storage System, " anon., n. d., p. 6. I am grateful to Dai Edwards for sending me a copy of this document.
121. Eckert, Lukoff, and Smoliar, "A Dynamically Regenerated Electrostatic Memory System, " pp. 498-510.
122. Eckert, Lukoff, and Smoliar, "A Dynamically Regenerated Electrostatic Memory System, " pp. 499, 502.
123. Williams, interview by C. Evans, Kilburn, "A Storage System for use with Binary Digital Computing Machines."
124. The exact date on which one-digit storage was achieved is uncertain. Kilburn was reported (c. 1950) as "quite certain" that he was told of this success when he joined Williams' project prior to the end of October 1946 "Williams Cathode Ray Tube Storage: Evidence Relating to the Origin of the Invention and the Dissemination of Information on the Operation of the Storage System, " p. 7). However, Kilburn said in interview with me in 1997 that "it was probably early in November that one single digit was stored by the anticipation pulse method." In 1975, Williams also recollected that this occurred in Nov. 1946 (Williams, "Early Computers at Manchester University, " p. 328). Williams lodged a draft patent application with the Ministry of Supply in Nov. 1946, and a formal application was made to the London Patent Office in Dec. 1946.
125. T. Kilburn, interview by B. J. Copeland, July 1997; T. Kilburn, "A Storage System for use with Binary Digital Computing Machines, " section 3. (The anticipation pulse is misdescribed in a recent article in Annals (D. Anderson, "Frederic Calland Williams: The Manchester Baby's Chief Engineer, " vol. 29, no. 4, 2007, p. 91.) This article conflates switch-on and switch-off effects and conflates the anticipation pulse method with later methods discovered by Kilburn.
126. F. C. Williams and T. Kilburn, "The University of Manchester Computing Machine, " Rev. of Electronic Digital Computers: Joint AIEE-IRE Computer Conf., Am. Inst. of Electrical Engineers, 1952, p. 57.
127. "Minutes of the Executive Committee of the National Physical Laboratory, " NPL Library, 22 Oct. 1946.
128. A. Hodges, Alan Turing: The Enigma, Vintage, 1992, p. 558.
129. "Minutes of the Working Party on Circuitry, " TRE, 7 Aug. 1946, Nat'l Archive for the History of Computing, Uni. of Manchester.
130. That is the account given in, for example, Wilkes and Kahn, "Tom Kilburn CBE FREng."
131. Croarken, Early Scientific Computing in Britain, p. 121.
132. M. R. Williams, A History of Computing Technology, 2nd ed., IEEE CS Press, 1997, p. 311.
133. J. P. Eckert, "The ENIAC, " A History of Computing in the Twentieth Century, N. Metropolis, J. Howlett, and G. C. Rota, eds., Academic Press, 1980, p. 534. Williams mentions iconoscope storage in his original 1946 patent.
134. F. C. Williams to R. A. Watson-Watt, 6 July 1950, "Williams Cathode Ray Tube Storage: Evidence Relating to the Origin of the Invention and the Dissemination of Information on the Operation of the Storage System."
135. "Interview with Dr. F. C. Williams, O. B. E. Group Leader at T. R. E., " typescript, n. d., c. 1945, TRE records.
136. Croarken Early Scientific Computing in Britain, p. 121. Since 2000, the relevant correspondence has been available at http://www.AlanTuring.net/turing- archive/archive/index/aceindex.html#1946.
137. J. R. Womersley to O. G. Sutton, 8 May 1946 Woodger Papers. Also available at http://www.AlanTuring.net/turing-archive/archive/l/l50/L50-001. html.
138. D. H. Black to J. R. Womersley, received 17 May 1946, Woodger Papers. Also available at, http://www.AlanTuring.net/turing-archive/archive/l/l50/L50- 003.html.
139. C. G. Darwin to Sir Edward Appleton, 13 Aug. 1946, Nat'l Archives/Public Record Office, document reference DSIR 10/275 (see also http://www.AlanTuring. net/darwin-appleton-13aug46);
140. E. S. Hiscocksto F. C. Williams, 31 Jan. 1947, Nat'l Archive for the History of Computing, Univ. of Manchester.
141. Anderson, "Frederic Calland Williams: The Manchester Baby's Chief Engineer, " p. 91.
142. See http://www.bcs.org/server.php?show=ConWebDoc.17134, p. 14.
143. See C. G. Darwin to Sir Edward Appleton, 13 Aug. 1946.
144. Anderson alludes to Womersley's letter of 8 May (Anderson, "Frederic Calland Williams: The Manchester Baby's Chief Engineer, " p. 91) but misdescribes it in significant ways, saying that it was written to TRE (instead of RRDE) and that it enquired about the state of research at TRE "into mercury delay lines" (instead of the state of research at RRDE into electronic storage tubes).
145. Some accounts have Telecommunications Research Establishment Automatic Computer.
146. A. M. Uttley et al., "The T. R. E. Parallel Electronic Digital Computer, " TRE, 27 Mar. 1951, DERA, TRE Library, Historical Collection EQUIP H336;
147. B. V. Bowden, ed., Faster Than Thought, Sir Isaac Pitman & Sons, 1953, chap. 10;
148. R. H. A. Carter, "The TRE High-speed Digital Computer, " Automatic Digital Computation, Proc. Symp. held at the Nat'l Physical Lab., Her Majesty's Stationery Office, 1954;
149. M. Campbell-Kelly, "The Development of Computer Programming in Britain (1945 to 1955), " Annals of the History of Computing, vol. 4, no. 2, 1982, p. 129.
150. The TREAC was parallel in the sense that all 24 digits of a word were retrieved simultaneously from an array of 24 Williams-Kilburn tubes. Earlier British machines had incorporated parallelism in other ways; the Pilot Model ACE, for example, had a parallel hardware multiplier, and there was provision in the Pilot Model ACE for various operations to be carried out simultaneously.
151. Williams, interview by Evans J. S. Small, "Engineering, Technology and Design: The Post-Second World War Development of Electronic Analogue Computers, " History and Technology, vol. 11, 1994, p. 38. I am grateful to David Clark for information about Uttley's wartime work.
152. A. M. Uttley, "Electronic Digital Computers, " TRE Physics Dept. Lecture Series, 27 Mar., 2 Apr., 10 Apr, 1947. I am grateful to Dai Edwards for supplying me with a copy of Uttley's typescript.
153. S. D. Smith, "Robert Allan Smith, " Biographical Memoirs of Fellows of the Royal Society, vol. 28, 1982, pp. 485-486.
154. Ware, "The History and Development of the Electronic Computer Project at the Institute for Advanced Study, " pp. 16-17.