by Brian Dear
In January 1963, an article entitled “Large Displays: Military Market Now, Civilian Next” would appear in Electronics magazine. It described three different engineering designs for large flat, digital displays, and featured an illustration of a large auditorium with seated rows of military men viewing two huge flat wall displays showing maps and trajectories. This was what one company, Lear Siegler, envisioned. They already had a contract with the Navy to build small flat panel displays using two sheets of glass as a “sandwich” around an inner “slice” of transparent ceramic material. One of the two sheets of glass contained horizontal rows of tiny electrode wires (so tiny they were effectively invisible to the human eye) and the other sheet contained vertical columns of electrodes. The inner “slice” of the sandwich was pockmarked with a grid of many tiny 0.05-inch holes drilled into the ceramic and then filled with neon gas. The holes were spaced to sit directly on top of the intersections of the electrodes, which were exposed to the gas like in a Nixie tube. The theory held that if you sent an electrical charge through a particular horizontal electrode and the corresponding vertical electrode, the two of which intersected over a specific “cell” of gas, that cell, and only that cell, would illuminate. Repeat quickly enough with different horizontal and vertical electrodes, and you have “pixels” across the display lighting up. Presto: you’ve got a flat panel display. One problem Lear Siegler continued to run into, however, was that adjacent cells tended to light up as well as the intended cell. That remained a stumbling block for the company, but would later serve as an eye-opener for the PLATO team, who studied Lear Siegler’s results carefully.
Lear Siegler’s belief that they could build large flat displays for the military was a natural extension of an idea already well understood. With the display Lear Siegler proposed, with its cross-hatched conductors sandwiched between sheets of glass, a grid of thousands of small gas-filled holes wherever the X and Y conductors crossed, the priority seemed to be getting a large display to work, not necessarily figuring out how to solve the digital memory that the display would rely on. If the memory wound up costing hundreds of millions of dollars, oh well, that was the military’s problem. PLATO didn’t have millions of dollars lying around. The memory problem would need to be solved.
For a number of years, two camps of researchers around the country had been exploring ways to use grids of tiny wires across tiny pockets of gas plasma: one camp was interested in creating displays, and the other was interested in creating computer memory, as it was theorized that gas plasma had inherent memory characteristics if you set up the wires, voltage, gas, and glass in just the right way. So far no one, including Lear Siegler, had figured out how to create a single gas plasma device that could function as both a display and a memory. It was not clear that anyone ever would.
This is where Bitzer and PLATO began poking around. Through their research they found patents filed in the late 1950s that were focused on gas plasma devices. In retrospect, the work is remarkable if for no other reason than that it was undertaken by none other than Douglas Engelbart, who, by the time Bitzer and company came across his patents, had already abandoned the research and moved over to a project that would lead to inventing the mouse and that inspired—perhaps launched—the Silicon Valley personal computing revolution. But back in the 1950s Engelbart was trying to make a name for himself with gas plasma matrices for display and memory use. He was not successful. But his work left clues…
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Two years younger than Bitzer, Robert Willson was a grad student who had earned a bachelor’s in engineering physics and a master’s in physics at Illinois. He took a graduate course in circuit theory by Dr. Mac E. Van Valkenburg, and, says Willson, “I was incredibly turned on by what he did. I mean, he was probably my first professor who really got me excited about learning. And I thought, Gee, I want to switch to electrical engineering and do my PhD in circuit theory, something related to that.” He switched and found himself with an assistantship at CSL. While he was considering writing his PhD thesis on graph theory or circuit theory, at the same time, Bitzer was beginning to poke around with the idea of a plasma display with inherent memory. “All of a sudden it dawned on me,” Willson recalls. He would work with Bitzer to attempt to create a plasma display and base his thesis on the work.
In early 1962 Willson built a crude one-cell model of a plasma display in a glass tube. Inside the tube, emptied of air to the point of being a vacuum and then backfilled with argon—they hadn’t begun trying neon yet—was a “sandwich” of super-thin, little square sheets of glass, the kind of glass used to make microscope slides. The outer sheets of glass—think of them as tiny slices of “bread” in this sandwich—each had a thin strip of nickel wire running across it, one serving as anode, and one as cathode. In between the two slices was placed a sheet of glass into which a tiny dot had been drilled. Inside that tiny dot was a small amount of the argon gas. The idea was to see what would happen when they ran an electrical current across the gas inside this sandwich of glass and nickel wires. What they discovered was that this was not going to be easy.
“From my perspective,” says Willson, “none of us really knew anything about vacuum physics. We were very naive.” After the first three months of work, Willson declared in a CSL Progress Report that he had just spent his time on “familiarization with vacuum techniques” and “preliminary investigations into the characteristics of the one-hole storage tube.” He was trying to get consistent data readings while charging a tiny hole of gas inside the glass sandwich, but the readings were far from consistent. Plus, he discovered there was contamination from air leaks in the gas cell and “burning” of the tube’s components from the voltage. Over the summer of 1962, Willson fixed the air contamination and burning problems, only to run into a new problem, “sputtering.” When he applied voltage to the gas, the excited gas emitted ions, which over time bombarded the surfaces of the nickel anode and cathode, making them less effective. He was going to have to build new tubes and try different gases, pressures, and voltages. So it went: as soon as Willson knocked down one problem, new ones popped up, and the slow-going would continue well into 1963.
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In the 1950s, the government of India created the Indian Institutes of Technology, with plans for several campuses around the nation. American universities, including the University of Illinois, partnered with IIT, which would become the MIT of India, to help it grow its own engineering and computer science departments.
In April 1963, UI professor Gilbert Fett proposed that it was time for IIT’s Kharagpur campus to get its own IBM 650 digital computer. He suggested that twenty-nine-year-old Donald Bitzer was just the man for the project. At first hesitant to go on such a journey, over some months Bitzer warmed to the idea. PLATO I and II were done; PLATO III was well under way running on the CDC 1604. Even the plasma display project was coming along. Six months, a year: why not?
Dan Alpert was not so happy about Bitzer, the heart and soul of the PLATO project, going off to India, when so much work had yet to be done. The mere mention to Alpert of the word “India” forty years later instantly sparked a response of “Oh shit, just an adventure!” The PLATO project was growing, gaining steam, and its director was going to be eight thousand miles away with unreliable and slow communications with the outside world. “Who was there to run the show?” Alpert said. Despite the concerns, he did not stop Bitzer from going. Bitzer did have high-ranking champions cheering him on. One of them was William Everitt, the dean of the engineering school. “He was fascinated with what Bitzer was doing,” says Jack Desmond. “The revolutionary implications of what he was doing were really quite well known to the administration and he had an enormous amount of visibility. Once you see genius like that then you’re quite willing to overlook some of the more mundane duties that professors perform, when this guy’s presumably making much greater contributions to the educational enterprise through his vision.”
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As 1963 wore on
, Robert Willson was conferring more and more with other CSL people for ideas on the plasma panel project, including Hiram Gene Slottow, known to all as “Gene,” a research physicist. Slottow once described the early days of the project this way: “Neither Bitzer nor Willson was an expert on gas discharge phenomena, but Bitzer’s style was (and is) to jump into a program with great imagination and energy, make mistakes, and learn as he goes along.”
Thirteen years older than Bitzer, Slottow had been an Army engineer during World War II, working at the Aberdeen Proving Ground in Maryland. His wife, Irene, met him there when she was a USO hostess. “I was taking commercial art classes,” she says, “and looking for a beautiful profile to draw…and there he was, surrounded by USO hostesses. A very charming, very gentle man.” Gene inherited a grand piano from a wealthy aunt, and they took it wherever they went from that point on. He was an excellent pianist and often considered going professional. “He really wanted to be a jazz musician,” she says. But the world had other plans. Once, during a trip to Chicago in the 1950s, he met a UI physics professor who urged him to consider joining CSL. Gene was ready for a change, and said he would come for a year, just to try it out. He wound up staying, even completing a PhD along the way. “It was really a very interesting group,” Irene says, “and he just loved it.” If Bitzer was a “wild man” within CSL, Slottow was a quieter one, widely regarded as a scholar and a gentleman, a careful writer and thoughtful presenter. Slottow did not share Bitzer’s car-salesman personality. “Don was really one of a kind,” says Irene. “He didn’t follow any rules…[and] he created an awful lot of controversy.”
Now Bitzer and Willson were conferring with Slottow on the preliminary work on the plasma displays, still only one-pixel test models plagued with setbacks and surprises as they learned more each day about how unwilling a wild and free Nature was to be harnessed. But Nature would soon learn that it was no match for Bitzer, Willson, and Slottow.
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In August 1963, Bitzer learned that IBM had unilaterally changed their mind about donating a 650 computer to ITT, and instead would give a less powerful 1620 machine. By December, IBM was trying to back out of even supplying ITT with any computer at all. Gilbert Fett pushed back, and IBM agreed to stick with the plan. Bitzer, his wife, Maryann, and their toddler son, David, began their westward journey from St. Louis on January 10, 1964, flying Pan Am the whole way. At each stop they rested at a hotel for a day or two before moving on. They arrived in Kharagpur on January 22. They found their bungalow on the outskirts of town at the edge of dense tropical jungle.
Despite the temperature sometimes topping 113 degrees, India did not stop Bitzer from his daily running routine. A British neighbor said that until Bitzer arrived, “only mad dogs and Englishmen went out in the midday sun.” The “boiling sun,” says Maryann, was not enough to stop him. “He would also race with the rickshaw drivers. He’d be out jogging, and these fellows, they were on bicycle rickshaws—Don doesn’t ever meet a stranger without talking, so he would always talk to them or call to them when he went by. It was all in fun, he would race them and they would be pulling their rickshaw with their bicycle and racing him, but he was not looked upon kindly by some of his colleagues for doing this because the caste system was still pretty evident and they didn’t like him talking to this lower caste of people.” Bitzer, always notorious for his jogging outfits, would later remark, of his time running in India, that “I was the best dressed person, jogging person, in the jungle.” Says Maryann, “He was the only dressed person in the jungle.”
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Back in Illinois, the PLATO team in CSL continued their work in hardware and software development. Circuitry was designed and built to enable twenty simultaneous PLATO III terminals to run at the same time. CATO, the Compiler for Automatic Teaching Operations, developed by Masako Secrest and Steve Singer, became operational, as did CATORES, the resident CATO program that Andy Hanson had created. Meanwhile, more and more lessons were beginning to appear. “PROOF” was a lesson to help students with mathematical problem solving. “Alphabat,” designed to help young children learn the letters of the alphabet, was a new lesson authored by Amy Alpert (daughter of Dan Alpert), one of the high school kids who like Mike Walker worked on PLATO-related projects with Bitzer as mentor. “Kids who identified the correct letter on the screen were given an M&M,” says Mike Walker, “which was ejected by a contraption powered by a washing machine relay….It was a bit too powerful and occasionally obliterated the piece of candy.” There were even new lessons designed to help potential lesson authors learn how to create PLATO lessons. This would become a common trait of PLATO over the coming decades: use PLATO itself to teach people how to use PLATO.
William Golden, who had gotten involved with PLATO from Max Beberman’s New Math team at UICSM down the street, and was now involved in the project to build lesson PROOF, found Bitzer’s India trip ill-timed and “terrible.” It “arrested,” he says, the forward momentum of the project. Not only that, Bitzer’s long absence impacted the special culture he had nurtured. “The culture of PLATO was set by Bitzer,” says Golden. “And he was a remarkable administrator. Bitzer didn’t care about your education, your background. It was what you could do. If…an undergraduate member of the group had the best idea, he drove the group. It sounds impossible but you could have full professors, researchers, PhDs, graduate students, and undergraduates working together….Whoever had the best ideas drove the projects in most cases.”
Bitzer had only been gone a few weeks when concerns grew that other projects within CSL were starting to cannibalize the PLATO project. “Please make sure,” Bitzer wrote to Tebby Lyman on February 7, “that none of the PLATO staff or space is obtained by other groups since we will need all the staff and space this coming September.” He wrote letters to Robert Willson to instruct him what to do next with his plasma display experiments.
Word eventually reached ARPA, one of the agencies funding CSL and PLATO, that Bitzer had embarked on a plasma display project on top of what he was supposed to be doing with PLATO. “The first money for this came from the behavioral science branch of ARPA, and they didn’t want it for this,” says Bitzer. “They were very upset with me. I was in India, and I was working on this, but we were also working on advancing PLATO, and they gave the money to essentially find what are the ten most important learning concepts using computers. That was the behavioral science branch of ARPA. The university signed for it to get the money, but when I got back and saw it I said, I would have never signed this because what we want to do, the most important problem is to get a display we can believe in. So I just took the money—it was a small grant, I believe it was $50,000—I took the money and said we’re going to use it for people to help develop the display. The behavioral science branch was really upset. They were really going to chew me out.”
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Back in India, Bitzer found a high-frequency oscilloscope stored away in the electrical engineering department head’s office. Two undergraduate IIT students, Brij Arora and Suhas S. Patil, were working on a project at the time and needed that oscilloscope to test their circuits. Bitzer, adept at ways of bypassing bureaucracy so people could stay productive and get things done, showed the two students a way to get access to it. Arora impressed Bitzer and he began attending some of his lectures and discussions on how to use computers and what makes them tick. But he also gave lectures on other things of interest to him, especially his pet project, the plasma panel. “Is it possible to make a flat panel display out of this stuff?” Bitzer would ask the students. Arora was particularly interested in hearing about this plasma display. Little did Bitzer know just how interested Arora was.
Nehru, the prime minister of India, died unexpectedly in late May. The nation of India shut down in mourning. Everything in India stopped, including transport of the IBM 1620. Finally, a mere two weeks before the Bitzers were scheduled to climb aboard Pan Am for the westward journey home through the Middle East and southern Europe,
the IBM 1620 arrived at Kharagpur. Then Bitzer received a request from a USAID official at the U.S. embassy in New Delhi asking if he could stay another three months. He responded that would be impossible, due to pressure to get back to the PLATO and plasma projects, not to mention a desire to get his family back home after six months in India. Eight thousand miles away, Alpert went into a brief tizzy over the thought of Bitzer staying longer. He immediately sent a cable: DEAN EVERITT, TEBBY LYMAN, AND DAN ALPERT EXPECT YOU BACK THIS SUMMER. WE KNOW OF NO OTHER PROPOSAL FOR EXTENSION OF YOUR STAY. CARRY OUT ORIGINAL RETURN PLANS PLEASE. Over the two final weeks Bitzer scrambled to work with the IIT students and other faculty to get the 1620 machine up and running.
He was back in Urbana the first week of July.
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Sometimes the best way to achieve a breakthrough when struggling with a tough technical problem is to get far away from it for a while, then come back. This may have been the case with the plasma display project, for it was not long—indeed, only days—after Bitzer returned to Illinois that they achieved a major breakthrough. By July 1964, Willson had made good progress on the plasma panel prototype, or at least had a much better understanding of the factors still holding the project back from success. Plus, he had had regular and increasing help from Slottow. Their prototype was still a single pixel, but having Slottow’s mind, as well as that of another CSL physicist, Frank Propst, cranking away along with Willson’s on how to achieve inherent memory in the display, was paying off. They noticed that when voltage was applied to the gas cell, a charge built up against the surfaces of the cell. They considered whether this charge buildup was useful or a hindrance. Up until this point, Willson had been doing roughly what the Lear Siegler people had been doing: attaching the super-thin electrodes to the inside surfaces of the glass sandwich, meaning the electrodes were in contact with the gas. The Lear Siegler team felt that some sort of resistor was necessary to prevent the direct current (DC) voltage from arcing across the gas from the one electrode to the other. Lear Siegler had made some progress with this approach, but had only been able to create a panel with 10 x 10 pixels. But then Bitzer and Slottow had an idea.
