Von Neumann’s series of meetings with the ENIAC team, and in particular four formal sessions he held with them in the spring of 1945, took on such significance that minutes were taken under the title “Meetings with von Neumann.” Pacing in front of a blackboard and ringleading the discussion with the engagement of a Socratic moderator, he absorbed ideas, refined them, and then wrote them on the board. “He would stand in front of the room like a professor, consulting with us,” Jean Jennings recalled. “We would state to him a particular problem that we had, and we were always very careful that the questions represented fundamental problems that we were having and not just mechanical problems.”53
Von Neumann was open but intellectually intimidating. When he made pronouncements, it was unusual for anyone to push back. But Jennings sometimes did. One day she disputed one of his points, and the men in the room stared at her incredulously. But von Neumann paused, tilted his head, and then accepted her point. Von Neumann could listen well, and he had also mastered the ingratiating art of feigning humility.54 “He was an amazing combination of a very brilliant man who knows that he’s brilliant, but at the same time is very modest and shy about presenting his ideas to other people,” according to Jennings. “He was very restless and would march back and forth across the room, yet when he presented his ideas it was almost as though he were apologizing for disagreeing with you or thinking of a better idea.”
Von Neumann was especially good at devising the fundamentals of computer programming, which was still an ill-defined craft that had advanced little in the century since Ada Lovelace wrote down the steps for getting the Analytical Engine to generate Bernoulli numbers. Creating an elegant instruction set, he realized, involved both rigorous logic and precise expression. “He was very thorough in explaining why we needed a particular instruction or why we could do without an instruction,” Jennings recounted. “It was the first time that I had ever realized the importance of instruction codes, the logic behind them and the ingredients that a whole instruction set must have.” It was a manifestation of his broader talent, which was to get to the essence of a new idea. “The thing that Von Neumann had, which I’ve noticed that other geniuses have, is the ability to pick out, in a particular problem, the one crucial thing that’s important.”55
Von Neumann realized that they were doing more than merely improving the ENIAC so that it could be reprogrammed more quickly. More significantly, they were fulfilling Ada’s vision by creating a machine that could perform any logical task on any set of symbols. “The stored-program computer, as conceived by Alan Turing and delivered by John von Neumann, broke the distinction between numbers that mean things and numbers that do things,” George Dyson wrote. “Our universe would never be the same.”56
In addition, von Neumann grasped, more readily than his colleagues, an important attribute of commingling data and programming instructions in the same stored memory. The memory could be erasable, what we now call read-write memory. This meant that the stored program instructions could be changed not just at the end of a run but anytime the program was running. The computer could modify its own program based on the results it was getting. To facilitate this, von Neumann came up with a variable-address program language that enabled an easy switch to substitute instructions while the program was running.57
The team at Penn proposed to the Army that a new and improved ENIAC be built along these lines. It would be binary rather than decimal, use mercury delay lines for memory, and include much, though not all, of what became known as “von Neumann architecture.” In the original proposal to the Army, this new machine was called the Electronic Discrete Variable Automatic Calculator. Increasingly, however, the team started referring to it as a computer, because it would do so much more than merely calculate. Not that it mattered. Everyone simply called it EDVAC.
* * *
Over the ensuing years, at patent trials and conferences, in books and dueling historical papers, there would be debates over who deserved the most credit for the ideas developed in 1944 and early 1945 that became part of the stored-program computer. The account above, for example, gives primary credit to Eckert and Mauchly for the stored-program concept and to von Neumann for realizing the importance of the computer’s ability to modify its stored program as it ran and for creating a variable-address programming functionality to facilitate this. But more important than parsing provenance of ideas is to appreciate how the innovation at Penn was another example of collaborative creativity. Von Neumann, Eckert, Mauchly, Goldstine, Jennings, and many others batted around ideas collectively and elicited input from engineers, electronics experts, material scientists, and programmers.
John von Neumann (1903–57) in 1954.
Herman Goldstine (1913–2004) circa 1944.
Presper Eckert (center) and CBS’s Walter Cronkite (right) look at an election prediction from UNIVAC in 1952.
Most of us have been involved in group brainstorming sessions that produced creative ideas. Even a few days later, there may be different recollections of who suggested what first, and we realize that the formation of ideas was shaped more by the iterative interplay within the group than by an individual tossing in a wholly original concept. The sparks come from ideas rubbing against each other rather than as bolts out of the blue. This was true at Bell Labs, Los Alamos, Bletchley Park, and Penn. One of von Neumann’s great strengths was his talent—questioning, listening, gently floating tentative proposals, articulating, and collating—for being an impresario of such a collaborative creative process.
Von Neumann’s propensity to collect and collate ideas, and his lack of concern for pinning down precisely where they came from, was useful in sowing and fertilizing the concepts that became part of EDVAC. But it did sometimes rankle those more concerned about getting credit—or even intellectual property rights—where due. He once proclaimed that it was not possible to attribute the origination of ideas discussed in a group. Upon hearing that, Eckert is said to have responded, “Really?”58
The benefits and drawbacks of von Neumann’s approach became apparent in June 1945. After ten months of buzzing around the work being done at Penn, he offered to summarize their discussions on paper. And that is what he proceeded to do on a long train ride to Los Alamos.
In his handwritten report, which he mailed back to Goldstine at Penn, von Neumann described in mathematically dense detail the structure and logical control of the proposed stored-program computer and why it was “tempting to treat the entire memory as one organ.” When Eckert questioned why von Neumann seemed to be preparing a paper based on the ideas that others had helped to develop, Goldstine reassured him: “He’s just trying to get these things clear in his own mind and he’s done it by writing me letters so that we can write back if he hasn’t understood it properly.”59
Von Neumann had left blank spaces for inserting references to other people’s work, and his text never actually used the acronym EDVAC. But when Goldstine had the paper typed up (it ran to 101 pages), he ascribed sole authorship to his hero. The title page Goldstine composed called it “First Draft of a Report on the EDVAC, by John von Neumann.” Goldstine used a mimeograph machine to produce twenty-four copies, which he distributed at the end of June 1945.60
The “Draft Report” was an immensely useful document, and it guided the development of subsequent computers for at least a decade. Von Neumann’s decision to write it and allow Goldstine to distribute it reflected the openness of academic-oriented scientists, especially mathematicians, who tend to want to publish and disseminate rather than attempt to own intellectual property. “I certainly intend to do my part to keep as much of this field in the public domain (from the patent point of view) as I can,” von Neumann explained to a colleague. He had two purposes in writing the report, he later said: “to contribute to clarifying and coordinating the thinking of the group working on the EDVAC” and “to further the development of the art of building high speed computers.” He said that he was not trying to assert any ownershi
p of the concepts, and he never applied for a patent on them.61
Eckert and Mauchly saw this differently. “You know, we finally regarded von Neumann as a huckster of other people’s ideas with Goldstine as his principal mission salesman,” Eckert later said. “Von Neumann was stealing ideas and trying to pretend work done at [Penn’s] Moore School was work he had done.”62 Jean Jennings agreed, later lamenting that Goldstine “enthusiastically supported von Neumann’s wrongful claims and essentially helped the man hijack the work of Eckert, Mauchly, and the others in the Moore School group.”63
What especially upset Mauchly and Eckert, who tried to patent many of the concepts behind both ENIAC and then EDVAC, was that the distribution of von Neumann’s report legally placed those concepts in the public domain. When Mauchly and Eckert tried to patent the architecture of a stored-program computer, they were stymied because (as both the Army’s lawyers and the courts eventually ruled) von Neumann’s report was deemed to be a “prior publication” of those ideas.
These patent disputes were the forerunner of a major issue of the digital era: Should intellectual property be shared freely and placed whenever possible into the public domain and open-source commons? That course, largely followed by the developers of the Internet and the Web, can spur innovation through the rapid dissemination and crowdsourced improvement of ideas. Or should intellectual property rights be protected and inventors allowed to profit from their proprietary ideas and innovations? That path, largely followed in the computer hardware, electronics, and semiconductor industries, can provide the financial incentives and capital investment that encourages innovation and rewards risks. In the seventy years since von Neumann effectively placed his “Draft Report” on the EDVAC into the public domain, the trend for computers has been, with a few notable exceptions, toward a more proprietary approach. In 2011 a milestone was reached: Apple and Google spent more on lawsuits and payments involving patents than they did on research and development of new products.64
THE PUBLIC UNVEILING OF ENIAC
Even as the team at Penn was designing EDVAC, they were still scrambling to get its predecessor, ENIAC, up and running. That occurred in the fall of 1945.
By then the war was over. There was no need to compute artillery trajectories, but ENIAC’s first task nevertheless involved weaponry. The secret assignment came from Los Alamos, the atomic weapons lab in New Mexico, where the Hungarian-born theoretical physicist Edward Teller had devised a proposal for a hydrogen bomb, dubbed “the Super,” in which a fission atomic device would be used to create a fusion reaction. To determine how this would work, the scientists needed to calculate what the force of the reactions would be at every ten-millionth of a second.
The nature of the problem was highly classified, but the mammoth equations were brought to Penn in October for ENIAC to crunch. It required almost a million punch cards to input the data, and Jennings was summoned to the ENIAC room with some of her colleagues so that Goldstine could direct the process of setting it up. ENIAC solved the equations, and in doing so showed that Teller’s design was flawed. The mathematician and Polish refugee Stanislaw Ulam subsequently worked with Teller (and Klaus Fuchs, who turned out to be a Russian spy) to modify the hydrogen bomb concept, based on the ENIAC results, so that it could produce a massive thermonuclear reaction.65
* * *
Until such classified tasks were completed, ENIAC was kept under wraps. It was not shown to the public until February 15, 1946, when the Army and Penn scheduled a gala presentation with some press previews leading up to it.66 Captain Goldstine decided that the centerpiece of the unveiling would be a demonstration of a missile trajectory calculation. So two weeks in advance, he invited Jean Jennings and Betty Snyder to his apartment and, as Adele served tea, asked them if they could program ENIAC to do this in time. “We sure could,” Jennings pledged. She was excited. It would allow them to get their hands directly on the machine, which was rare.67 They set to work plugging memory buses into the correct units and setting up program trays.
The men knew that the success of their demonstration was in the hands of these two women. Mauchly came by one Saturday with a bottle of apricot brandy to keep them fortified. “It was delicious,” Jennings recalled. “From that day forward, I always kept a bottle of apricot brandy in my cupboard.” A few days later, the dean of the engineering school brought them a paper bag containing a fifth of whiskey. “Keep up the good work,” he told them. Snyder and Jennings were not big drinkers, but the gifts served their purpose. “It impressed us with the importance of this demonstration,” said Jennings.68
The night before the demonstration was Valentine’s Day, but despite their normally active social lives, Snyder and Jennings did not celebrate. “Instead, we were holed up with that wonderful machine, the ENIAC, busily making the last corrections and checks on the program,” Jennings recounted. There was one stubborn glitch they couldn’t figure out: the program did a wonderful job spewing out data on the trajectory of artillery shells, but it just didn’t know when to stop. Even after the shell would have hit the ground, the program kept calculating its trajectory, “like a hypothetical shell burrowing through the ground at the same rate it had traveled through the air,” as Jennings described it. “Unless we solved that problem, we knew the demonstration would be a dud, and the ENIAC’s inventors and engineers would be embarrassed.”69
Jennings and Snyder worked late into the evening before the press briefing trying to fix it, but they couldn’t. They finally gave up at midnight, when Snyder needed to catch the last train to her suburban apartment. But after she went to bed, Snyder figured it out: “I woke up in the middle of the night thinking what that error was. . . . I came in, made a special trip on the early train that morning to look at a certain wire.” The problem was that there was a setting at the end of a “do loop” that was one digit off. She flipped the requisite switch and the glitch was fixed. “Betty could do more logical reasoning while she was asleep than most people can do awake,” Jennings later marveled. “While she slept, her subconscious untangled the knot that her conscious mind had been unable to.”70
At the demonstration, ENIAC was able to spew out in fifteen seconds a set of missile trajectory calculations that would have taken human computers, even working with a Differential Analyzer, several weeks. It was all very dramatic. Mauchly and Eckert, like good innovators, knew how to put on a show. The tips of the vacuum tubes in the ENIAC accumulators, which were arranged in 10 x 10 grids, poked through holes in the machine’s front panel. But the faint light from the neon bulbs, which served as indicator lights, was barely visible. So Eckert got Ping-Pong balls, cut them in half, wrote numbers on them, and placed them over the bulbs. As the computer began processing the data, the lights in the room were turned off so that the audience would be awed by the blinking Ping-Pong balls, a spectacle that became a staple of movies and TV shows. “As the trajectory was being calculated, numbers built up in the accumulators and were transferred from place to place, and the lights started flashing like the bulbs on the marquees in Las Vegas,” said Jennings. “We had done what we set out to do. We had programmed the ENIAC.”71 That bears repeating: they had programmed the ENIAC.
The unveiling of ENIAC made the front page of the New York Times under the headline “Electronic Computer Flashes Answers, May Speed Engineering.” The story began, “One of the war’s top secrets, an amazing machine which applies electronic speeds for the first time to mathematical tasks hitherto too difficult and cumbersome for solution, was announced here tonight by the War Department.”72 The report continued inside the Times for a full page, with pictures of Mauchly, Eckert, and the room-size ENIAC. Mauchly proclaimed that the machine would lead to better weather predictions (his original passion), airplane design, and “projectiles operating at supersonic speeds.” The Associated Press story reported an even grander vision, declaring, “The robot opened the mathematical way to better living for every man.”73 As an example of “better living,” Mauchly asse
rted that computers might one day serve to lower the cost of a loaf of bread. How that would happen he did not explain, but it and millions of other such ramifications did in fact eventually transpire.
Later Jennings complained, in the tradition of Ada Lovelace, that many of the newspaper reports overstated what ENIAC could do by calling it a “giant brain” and implying that it could think. “The ENIAC wasn’t a brain in any sense,” she insisted. “It couldn’t reason, as computers still cannot reason, but it could give people more data to use in reasoning.”
Jennings had another complaint that was more personal: “Betty and I were ignored and forgotten following the demonstration. We felt as if we had been playing parts in a fascinating movie that suddenly took a bad turn, in which we had worked like dogs for two weeks to produce something really spectacular and then were written out of the script.” That night there was a candle-lit dinner at Penn’s venerable Houston Hall. It was filled with scientific luminaries, military brass, and most of the men who had worked on ENIAC. But Jean Jennings and Betty Snyder were not there, nor were any of the other women programmers.74 “Betty and I weren’t invited,” Jennings said, “so we were sort of horrified.”75 While the men and various dignitaries celebrated, Jennings and Snyder made their way home alone through a very cold February night.
THE FIRST STORED-PROGRAM COMPUTERS
The desire of Mauchly and Eckert to patent—and profit from—what they had helped to invent caused problems at Penn, which did not yet have a clear policy for divvying up intellectual property rights. They were allowed to apply for patents on ENIAC, but the university then insisted on getting royalty-free licenses as well as the right to sublicense all aspects of the design. Furthermore, the parties couldn’t agree on who would have rights to the innovations on EDVAC. The wrangling was complex, but the upshot was that Mauchly and Eckert left Penn at the end of March 1946.76