29. John Atanasoff, “Advent of Electronic Digital Computing,” Annals of the History of Computing, July 1984, 234.

30. Atanasoff, “Advent of Electronic Digital Computing,” 238.

31. Atanasoff, “Advent of Electronic Digital Computing,” 243.

32. Katherine Davis Fishman, The Computer Establishment (Harper and Row, 1981), 22.

33. Atanasoff testimony, Honeywell v. Sperry Rand, June 15, 1971, transcript p. 1700, in Burks, Who Invented the Computer?, 1144. The archives for the trial are at the University of Pennsylvania, http://www.archives.upenn.edu/faids/upd/eniactrial/upd8_10.html, and at the Charles Babbage Institute of the University of Minnesota, http://discover.lib.umn.edu/cgi/f/findaid/findaid-idx?c=umfa;cc=umfa;rgn=main;view=text;didno=cbi00001.

34. Atanasoff testimony, transcript p. 1703.

35. Atanasoff, “Advent of Electronic Digital Computing,” 244.

36. John Atanasoff, “Computing Machine for the Solution of Large Systems of Linear Algebraic Equations,” 1940, available online from Iowa State, http://jva.cs.iastate.edu/img/Computing%20machine.pdf. For detailed analysis, see Burks and Burks, The First Electronic Computer, 7 and passim.

37. Robert Stewart, “The End of the ABC,” Annals of the History of Computing, July 1984; Mollenhoff, Atanasoff, 73.

38. This section draws on John Mauchly oral history, conducted by Henry Tropp, Jan. 10, 1973, Smithsonian Institution; John Mauchly oral history, conducted by Nancy Stern, May 6, 1977, American Institute of Physics (AIP); Scott McCartney, ENIAC (Walker, 1999); Herman Goldstine, The Computer from Pascal to von Neumann (Princeton, 1972; locations refer to Kindle edition); Kathleen Mauchly, “John Mauchly’s Early Years,” Annals of the History of Computing, Apr. 1984; David Ritchie, The Computer Pioneers (Simon & Schuster, 1986); Bill Mauchly and others, “The ENIAC” website, http://the-eniac.com/first/; Howard Rheingold, Tools for Thought (MIT, 2000); Joel Shurkin, Engines of the Mind: A History of the Computer (Washington Square Press, 1984).

39. John Costello, “The Twig Is Bent: The Early Life of John Mauchly,” IEEE Annals of the History of Computing, 1996.

40. Mauchly oral history, AIP.

41. Costello, “The Twig Is Bent.”

42. McCartney, ENIAC, 82.

43. Kay McNulty Mauchly Antonelli, “The Kathleen McNulty Mauchly Antonelli Story,” Mar. 26, 2004, ENIAC website, https://sites.google.com/a/opgate.com/eniac/Home/kay-mcnulty-mauchly-antonelli; McCartney, ENIAC, 32.

44. Ritchie, The Computer Pioneers, 129; Rheingold, Tools for Thought, 80.

45. McCartney, ENIAC, 34.

46. Kathleen Mauchly, “John Mauchly’s Early Years.”

47. McCartney, ENIAC, 36.

48. Kathleen Mauchly, “John Mauchly’s Early Years.”

49. John Mauchly to H. Helm Clayton, Nov. 15, 1940.

50. John Mauchly to John de Wire, Dec. 4, 1940; Kathleen Mauchly, “John Mauchly’s Early Years.”

51. Mauchly to Atanasoff, Jan. 19, 1941; Atanasoff to Mauchly, Jan. 23, 1941; Mauchly oral history, Smithsonian; Burks, Who Invented the Computer?, 668.

52. The battle over what happened was fought out in the Annals of the History of Computing, with multiple articles, comments, and bitter letters. This section and that on the legal battle, below, derive from them. They include Arthur Burks and Alice Burks, “The ENIAC: First General-Purpose Electronic Computer,” with comments by John Atanasoff, J. Presper Eckert, Kathleen R. Mauchly, and Konrad Zuse, and a response by Burks and Burks, Annals of the History of Computing, Oct. 1981, 310–99 (more than eighty pages of this issue were devoted to the assertions and rebuttals, prompting some discomfort on the part of the editors); Kathleen Mauchly, “John Mauchly’s Early Years,” Annals of the History of Computing, Apr. 1984; John Mauchly, “Mauchly: Unpublished Remarks,” with an afterword by Arthur Burks and Alice Burks, Annals of the History of Computing, July 1982; Arthur Burks, “Who Invented the General Purpose Computer?” talk at the University of Michigan, Apr. 2, 1974; James McNulty, letter to the editor, Datamation, June 1980.

53. Lura Meeks Atanasoff testimony, Sperry v. Honeywell; Burks, Who Invented the Computer?, 1445.

54. Mollenhoff, Atanasoff, 114.

55. Mauchly oral history, Smithsonian; John Mauchly, “Fireside Chat,” Nov. 13, 1973, Annals of the History of Computing, July 1982.

56. Ritchie, The Computer Pioneers, 142.

57. Mauchly oral history, Smithsonian.

58. John Mauchly testimony, Sperry v. Honeywell ; Burks, Who Invented the Computer?, 429.

59. John Mauchly to John Atanasoff, Sept. 30, 1941, Sperry v. Honeywell trial records.

60. Atanasoff to Mauchly, Oct. 7, 1941, Sperry v. Honeywell trial records.

61. In addition to the sources cited below, this section draws from Peter Eckstein, “Presper Eckert,” Annals of the History of Computing, Spring 1996; J. Presper Eckert oral history, conducted by Nancy Stern, Oct. 28, 1977, Charles Babbage Institute, University of Minnesota; Nancy Stern, From ENIAC to UNIVAC (Digital Press, 1981); J. Presper Eckert, “Thoughts on the History of Computing,” Computer, Dec. 1976; J. Presper Eckert, “The ENIAC,” John Mauchly, “The ENIAC,” and Arthur W. Burks, “From ENIAC to the Stored Program Computer,” all in Nicholas Metropolis et al., editors, A History of Computing in the Twentieth Century (Academic Press, 1980); Alexander Randall, “A Lost Interview with Presper Eckert,” Computerworld, Feb. 4, 2006.

62. Eckert oral history, Charles Babbage Institute.

63. Eckstein, “Presper Eckert.”

64. Ritchie, The Computer Pioneers, 148.

65. Eckert oral history, Charles Babbage Institute.

66. John W. Mauchly, “The Use of High Speed Vacuum Tube Devices for Calculating,” 1942, in Brian Randell, editor, The Origins of Digital Computers: Selected Papers (Springer-Verlag, 1973), 329. See also John G. Brainerd, “Genesis of the ENIAC,” Technology and Culture, July 1976, 482.

67. Mauchly oral history, Smithsonian; Goldstine, The Computer from Pascal to von Neumann, 3169; McCartney, ENIAC, 61.

68. Burks, Who Invented the Computer?, 71.

69. McCartney, ENIAC, 89.

70. Eckert oral history, Charles Babbage Institute.

71. Eckert oral history, Charles Babbage Institute.

72. Eckert oral history, Charles Babbage Institute; Randall, “A Lost Interview with Presper Eckert.”

73. Hodges, Alan Turing, 3628.

74. In addition to the Hodges biography, Alan Turing, this section draws on B. Jack Copeland, Colossus: The Secrets of Bletchley Park’s Codebreaking Computers (Oxford, 2006); I. J. Good, “Early Work on Computers at Bletchley,” Annals of the History of Computing, July 1979; Tommy Flowers, “The Design of Colossus,” Annals of the History of Computing, July 1983; Simon Lavington, editor, Alan Turing and His Contemporaries (BCS, 2012); Sinclair McKay, The Secret Life of Bletchley Park: The History of the Wartime Codebreaking Centre by the Men and Women Who Were There (Aurum Press, 2010); and my visit to Bletchley Park and the scholars, tour guides, displays, and material available there.

75. Randall, “A Lost Interview with Presper Eckert.”

76. The archives for the Honeywell v. Sperry Rand trial. See also Charles E. McTiernan, “The ENIAC Patent,” Annals of the History of Computing, Apr. 1998.

77. Judge Earl Richard Larson decision, Honeywell v. Sperry Rand.

78. Randall, “A Lost Interview with Presper Eckert.”

CHAPTER THREE: PROGRAMMING

1. Alan Turing, “Intelligent Machinery,” National Physical Laboratory report, July 1948, available at http://www.AlanTuring.net/intelligent_machinery.