12. Ibid.

13. J.N. Wenger, H.T. Engstrom, and R.I. Meader, "History of the Bombe Project," OP-20-G Memorandum dated 30 May 1944, 2 (NARA Record Group 457, File #4584.) Hereafter referred to as Bombe History.

14. "E" refers to the Enigma problem. (Ibid., 6.)

15. Bombe History, 2.

16. Memorandum from OP-20-G, "Brief Resume of Op-20-G and British Activities vis-a-vis German Machine Ciphers," July 15,1944, 2.

17. Beesly, Patrick, "Ultra and the Battle of the Atlantic: The British View," Cryptologic Spectrum, v.8 n.l (Winter 1978), 7.

18. American Federation of Information Processing Societies, Computer Oral History Collection, 1969-1973, 1977. Interview with Joseph Desch and Robert Mumma. (Washington D.C.: Archives Center, National Museum of American History), 116.

19. Bombe History, 7.

20. Waves were women in the U.S. Navy. The acronym WAVES stood for Women Accepted for Volunteer Emergency Service.

21. Correspondence to the author from Robert Shade, February 11, 2000.

22. Atha, Bob, "The Electro-Mechanical Marvel," U.S. Naval Cryptologic Veterans Association (Paducah, KY: Turner Publishing Co., 1996), 60.

23. Anderson, Deborah, "Joseph Desch and Magic."

24. Correspondence to the author from Sue (Sadie) Unger Eskey, December 20,1999.

25. Dalton, Curt, Keeping the Secret: The WAVES & NCR (Dayton, OH: self-published, 1997), 21.