CHAPTER 7
"Theories of Memory"
p. 85
"Action this day," he scrawled. And so it was: See Colossus: The Secrets of Bletchley Park's Codebreaking Computers, ed. Jack Copeland
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a reported 103,325,660,891,587,134,000,000 possible combinations: This figure is taken from a Bletchley Park display.
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an army cryptologist named John Tiltman . . . managed to break the code: Information on Tiltman's role derived from Bletchley literature; Bill Tutte's contribution from Jack Copeland's article "The Modern History of Computing," in The Stanford Encyclopedia of Philosophy. Copeland also runs the excellent alanturing.net archive and corrects a lot of misconception and misinformation around this subject.
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A drawer could not be opened unless it was pushed in and out seven times: Dyson, p46, taken from Johnny, Klara von Neumann's unpublished memoir of her husband.
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von Neumann's clarity of thought was orders of magnitude greater: In Norman Macrae's book John von Neumann: The Scientific Genius Who Pioneered the Modern Computer, Game Theory, Nuclear Deterrence, and Much More, von Neumann's colleague and close friend, the Polish-American mathematician scientist Stanislaw Ulam, is quoted as suggesting that the von Neumann intelligence might be organized aurally rather than visually.
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Ada was beguiled by the metaphoric connection she saw between these machines: A general note here. I am aware of the diminutive way in which women are sometimes referred to by their first names, where a man ("Babbage," for instance) would not be. It has become conventional to refer to Ada Lovelace as "Ada" instead of Lovelace for good reason, though. Born Augusta Ada Byron, she later married William King, 8th Baron King, and became Lady King. A few years later, when her husband was made an Earl, she became the Countess of Lovelace. Do we call her "Byron," "King," and "Lovelace", depending on the phase of her life? "Ada" is the most consistent option.
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Max Newman later referred to these as "houses": This also from Copeland, ibid.
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Colossus was neither designed by Alan Turing nor built at Bletchley Park: After the war, Flowers was granted £1000 by the British government, which didn't cover his costs, but he shared a considerable part of the grant with his staff anyway. For more on this remarkable man and project, see the excellent, myth-busting works edited and written by the aforementioned Jack Copeland, Professor of Philosophy and Director of the Turing Archive for the History of Computing, starting with the books Colossus: The Secrets of Bletchley Park's Code-breaking Computers; Turing: Pioneer of the Information Age and The Turing Guide. Encyclopedia Britannica is also very good on Turing, Colossus and Bletchley Park, with the online Colossus page featuring a must-see Open University video about the computer historian Tony Sale's project to build a working replica of the code breaking machine—the result of which you can see at the National Museum of Computing, a short walk from the Bletchley Park site itself. I kick myself for never having visited Bletchley before I moved to the US: now I try to go whenever I return to the UK and urge anyone visiting or living there to make the 35-minute pilgrimage from London for themselves. There are few better ways to spend an afternoon. For further reading on the subject, George Dyson's Turing's Cathedral and Charles Petzold's Code are hard to beat.
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Newman and Turing appear to have steered Flowers toward making his machine programmable: According to Bletchley alum I. J. Good, quoted in George Dyson, Turing's Cathedral: The Origins of the Digital Universe (p. 256).
Turing . . . appears to have had little direct involvement in the first computer's development: Both dates given here are from Copeland, ibid, chapter on Colossus (p. 40 and 42)
"I don't think they [the Bletchley codebreakers] really understood what I was saying in detail": From Flowers' interview with Christopher Evans, 1977, quoted in Copeland, ibid
Newman and Turing appear to have steered Flowers toward making his machine programmable and animating the circuits with Boolean logic: From "Advances in I/O, Speedup, and Universality on Colossus, an Unconventional Computer," by Benjamin Wells, in Unconventional Computing (see bibliography for details)
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John von Neumann went to England in late April, 1943: Dyson, ibid.
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There is no explicit record of [von Neumann] having visited Flowers' team or Turing at Bletchley: von Neumann's mention of having met Newman revealed in "An Interview with NICOLAS C. METROPOLIS," conducted by William Aspray on 29 May 1987, Los Alamos, NM (Charles Babbage Institute, The Center for the History of Information Processing, University of Minnesota, Minneapolis.)
a staggering 17,468 vacuum tube switches and weighed a cool thirty tons: Dyson, ibid, p72
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Six young women were selected: See resources at the Eniac Programmers Project. Having been lost for decades, the ENIAC women's story was resurfaced in a 2014 documentary, The Computers. Also worth a visit on this subject is Walter Isaacson's book, The Innovators. When war ended and the men came home, these were some of the few women spared the fate of Rosie the Rivetter, as women were forced back into the home. "Rosie the Riveter" was a fictional character used to front a World War II campaign to bring American women into industry, to perform work traditionally done by the men away fighting. The campaign was wildly successful, and women participating in heavy industrial jobs during the war came to be known as "Rosies." A superb 1980 documentary (Rosie the Riveter by Connie Field) tells the by-turns delightful and heartrending story of Rosies' entry into industry and the campaign to push them back out when the men came home. And anyone who feels they haven't experienced enough fury or despair over irrational prejudice in the last few years could do very much worse than approach the online PDF of Jennifer S. Light's When Computers Were Women. This will make you feel bad, but also good, because it has so much fascinating detail about these truly remarkable women.
Men and women alike seem to have revered the Bacall-like Goldstine: From the Society of Women Engineers, "Adele Goldstine, the Woman Who Wrote the Book—All Together," Seabright McCabe, Society of Women Engineers magazine.
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They worked together, lived together, ate together: From oral history archived at the Computer History Museum in 2008
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by war's end, [the ENIAC women] understood computing better than anyone bar Turing: See Dyson, ibid. Von Neumann thought the future would be all about baking "rich functionality" into the hardware; thought programming would be a tedious technical exercise. By contrast, Turing saw the machine as a relatively trivial vehicle for software—saw programming as a potentially fascinating pursuit, a view subsequently proven by the ENIAC women.
thus was the "while loop" born: The ENIAC women also discovered the "infinite loop"—right before the machine's first demo to an audience of dignitaries. From an interview with Jean Jennings Bartik, part of the excellent Computer History Museum's oral history series: "The problem had been a rogue digit, causing a 'do' loop to run infinitely, ignoring the condition that it should stop at the point of impact and move on to the rest of the program. The demo went ahead and was a huge success ("one of the most exciting days of my life," says Jennings). Mauchly and Eckert had adapted their machine to reveal the flashing tips of the tubes, with the computer room lit to maximize dramatic effect. Calculations that took on average twelve hours by hand were finished in twenty seconds. Snyder Holberton and Jennings handed out printouts of the output as the program ran. The audience was knocked off its feet and ENIAC's unveiling made the front of the New York Times, with the story continuing inside." Of course, afterwards the men all went to a celebratory dinner, while the women were left to walk home in the freezing cold on their own.
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Grace Hopper and ENIAC alum Betty Snyder . . . would work together to blaze trails in that field: Betty Snyder Holberton went to Remington Rand and worked with Grace Hopper on aspects of COBOL and Fortran. She had a distinguished if largely unsung career (see W. Barkley Fritz, "The Women of ENIAC," IEEE Annals of the History of Computing, 1996.)
the program took a month to run: From Dyson, ibid
The first serious test problem run on ENIAC: Dyson, ibid (p. 76)
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writing STOP THE BOMB in dust on the windshield of [von Neumann's] Cadillac: ENIAC's most historically significant achievement may be the inspiration it afforded von Neumann, who heard about the computer while conducting studies into the feasibility of an American hydrogen bomb. In Turing's Cathedral, George Dyson notes the disapproval of von Neumann's project by fellow scientists at the IAS—and that, for all the Hungarian-American's genius, he appears to have favored a pre-emptive strike on the Soviet Union as the Cold War gathered. It's hard to imagine Turing being so cavalier.
the first flow-diagram coding: From Dyson, ibid (p. 209), quoting von Neumann's IAS friend Francois Ulam. "In that T-division coffee room, I had watched Johnny, when he was building his Princeton machine, cover a blackboard with the first stirrings of flow-diagram coding, while casting unconscious sidelong glances at every feminine pair of legs that went by."
We know he didn't intend it for publication at that point, because he repeatedly refers to sections that were never written: See "Introduction to 'The First Draft Report on the EDVAC' by John von Neumann" by Michael D. Godfrey, IEEE Annals of the History of Computing, Vol. 15, No. 4
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von Neumann regarded Alan Turing as conceptualizer of this new field: From Copeland, ibid, "The Modern History of Computing." In a 1943 letter, the Los Alamos physicist Stanley Frankel, responsible with von Neumann and others for mechanizing the large-scale calculations involved in the design of the atomic bomb, described Von Neumann's view of the importance of Turing's 1936 paper, saying: "I know that in about 1943 or '44 von Neumann was well aware of the fundamental importance of Turing's paper of 1936 . . . von Neumann introduced me to that paper and at his urging I studied it with care. Many people have claimed von Neumann as 'father of the computer' (in a modern sense of the term) but I am sure that he would never have made that mistake himself. He might well be called the midwife, perhaps, but he firmly emphasized to me, and to others I am sure, that the fundamental conception is owing to Turing, insofar has not anticipated by Babbage . . . Both Turing and von Neumann, of course, also made substantial contributions to the 'reduction to practice' of these concepts but I would not regard these as comparable in importance with the introduction and explication of the concept of a computer able to store in its memory its program of activities and of modifying that program in the course of these activities." This quoted in Randall, "On Alan Turing and the Origins of Digital Computers," 1972, Computing Laboratory, Newcastle upon Tyne.
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almost nothing in a programming language is real in the sense of having more than a tenuous, figurative relationship to what we call it: There is at least one exception. Numbers, strings (e.g. "Smith despairs of Scrabble") and true/false Booleans are among a very limited category of objects called literals, which carry the same meaning they would in the outside world.
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This doesn't mean that trailblazers all saw the future of computing in the same way: See "The origins and development of the ACE project" in Alan Turing's Automatic Computing Engine: The Master Codebreaker's Struggle to build the Modern Computer, ed. Jack B. Copeland. Also "Turing's Automatic Computing Engine", in "The Modern History of Computing", Stanford Encyclopedia of Philosophy, in which the same Jack Copeland fascinatingly elucidates:
Turing and Newman were thinking along similar lines. In 1945 Turing joined the National Physical Laboratory (NPL) in London, his brief to design and develop an electronic stored-program digital computer for scientific work. (Artificial Intelligence was not far from Turing's thoughts: he described himself as 'building a brain' and remarked in a letter that he was 'more interested in the possibility of producing models of the action of the brain than in the practical applications to computing.') John Womersley, Turing's immediate superior at NPL, christened Turing's proposed machine the Automatic Computing Engine, or ACE, in homage to Babbage's Difference Engine and Analytical Engine.
Turing's 1945 report 'Proposed Electronic Calculator' gave the first relatively complete specification of an electronic stored-program general-purpose digital computer.
The first electronic stored-program digital computer to be proposed in the U.S. was the EDVAC (see below). The 'First Draft of a Report on the EDVAC' (May 1945), composed by von Neumann, contained little engineering detail, in particular concerning electronic hardware (owing to restrictions in the U.S.). Turing's 'Proposed Electronic Calculator', on the other hand, supplied detailed circuit designs and specifications of hardware units, specimen programs in machine code, and even an estimate of the cost of building the machine (£11,200). ACE and EDVAC differed fundamentally from one another; for example, ACE employed distributed processing, while EDVAC had a centralized structure.
Turing saw that speed and memory were the keys to computing. Turing's colleague at NPL, Jim Wilkinson, observed that Turing 'was obsessed with the idea of speed on the machine' [Copeland 2005, p. 2]. Turing's design had much in common with today's RISC architectures and it called for a high-speed memory of roughly the same capacity as an early Macintosh computer (enormous by the standards of his day). Had Turing's ACE been built as planned it would have been in a different league from the other early computers. However, progress on Turing's Automatic Computing Engine ran slowly, due to organizational difficulties at NPL, and in 1948 a 'very fed up' Turing (Robin Gandy's description, in interview with Copeland, 1995) left NPL for Newman's Computing Machine Laboratory at Manchester University. It was not until May 1950 that a small pilot model of the Automatic Computing Engine, built by Wilkinson, Edward Newman, Mike Woodger, and others, first executed a program. With an operating speed of 1 MHz, the Pilot Model ACE was for some time the fastest computer in the world.
Sales of DEUCE, the production version of the Pilot Model ACE, were buoyant---confounding the suggestion, made in 1946 by the Director of the NPL, Sir Charles Darwin, that 'it is very possible that ... one machine would suffice to solve all the problems that are demanded of it from the whole country' [Copeland 2005, p. 4]. The fundamentals of Turing's ACE design were employed by Harry Huskey (at Wayne State University, Detroit) in the Bendix G15 computer (Huskey in interview with Copeland, 1998). The G15 was arguably the first personal computer; over 400 were sold worldwide. DEUCE and the G15 remained in use until about 1970. Another computer deriving from Turing's ACE design, the MOSAIC, played a role in Britain's air defences during the Cold War period; other derivatives include the Packard-Bell PB250 (1961).
For still more on the remarkable story, try "Alan Turing's Automatic Computing Engine: The Master Codebreaker's Struggle to build the Modern Computer," ed. Jack B. Copeland, Oxford Scholarship Online.
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Edsger Dijkstra...summarily blew out of the water: A review of the 1977 Turing Award Lecture, by John Backus.
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Bigelow questioned the persistence of the von Neumann architecture: Dyson, ibid (p. 62)
"What we are creating now is a monster": Quoted in Dyson, ibid (p. 62)
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More than one historian now claims the raid to have been a diversion: Most recently David O'Keefe in his 2012 book, One Day in August: Ian Fleming, Enigma and the Deadly Raid on Dieppe, and in the documentary Dieppe Uncovered.
a point-for-point description of Bond: From research displayed at Bletchley Park.
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Alfred Dilly Knox . . . was, like Turing, gay: During his time at the exclusive Eton College school, Knox is reported to have been the lover of classmate and future seminal economist John Maynard Keynes. See Supermac: The Life of Harold Macmillan, by D.R. Thorpe, Chatto & Windus, 2010 (p. 27).