In the summer of 1961, Alan Kotok and the other TMRC hackers learned that a new company was soon to deliver to MIT, absolutely free, the next step in computing, a machine that took the interactive principles of the TX-0 several steps further. A machine that might be even better for hackers than the TX-0 was.

The PDP-1. It would change computing forever. It would make the still hazy hacker dream come a little closer to reality.

Alan Kotok had distinguished himself as a true wizard on the TX-0, so much so that he, along with Saunders, Samson, Wagner, and a few others, had been hired by Jack Dennis to be the Systems Programming Group of the TX-0. The pay would be a munificent $1.60 an hour. For a few of the hackers, the job was one more excuse not to go to classes—some hackers, like Samson, would never graduate, and be too busy hacking to really regret the loss. Kotok, though, was able not only to manage his classes, but to establish himself as a “canonical” hacker. Around the TX-0 and TMRC, he was acquiring legendary status. One hacker who was just arriving at MIT that year remembers Kotok giving newcomers a demonstration of how the TX-0 worked: “I got the impression he was hyperthyroid or something,” recalled Bill Gosper, who would become a canonical hacker himself, “because he spoke very slowly and he was chubby and his eyes were half-closed. That was completely and utterly the wrong impression. [Around the TX-0] Kotok had infinite moral authority. He had written the chess program. He understood hardware.” (This last was not an inconsiderable compliment—“understanding hardware” was akin to fathoming the Tao of physical nature.)

The summer that the word came out about the PDP-1, Kotok was working for Western Electric, kind of a dream job, since of all possible systems the phone system was admired most of all. The Model Railroad Club would often go on tours of phone company exchanges, much in the way that people with an interest in painting might tour a museum. Kotok found it interesting that at the phone company, which had gotten so big in its decades of development, only a few of the engineers had a broad knowledge of the interrelations within that system. Nevertheless, the engineers could readily provide detail on specific functions of the system, like crossbar switching and step-relays; Kotok and the others would hound these experts for information, and the flattered engineers, probably having no idea that these ultra-polite college kids would actually use the information, would readily comply.

Kotok made it a point to attend those tours, to read all the technical material he could get his hands on, and to see what he could get by dialing different numbers on the complex and little-understood MIT phone system. It was basic exploration, just like exploring the digital back alleys of the TX-0. During that previous winter of 1960–61, the TMRC hackers had engaged in an elaborate “telephone network fingerprinting,” charting all the places you could reach by MIT’s system of tie lines. Though not connected to general telephone lines, the system could take you to Lincoln Lab, and from there to defense contractors all over the country. It was a matter of mapping and testing. You would start with one access code, add different digits to it, see who might answer, ask whoever answered where they were, then add digits to that number to piggyback to the next place. Sometimes you could even reach outside lines in the suburbs, courtesy of the unsuspecting phone company. And, as Kotok would later admit, “If there was some design flaw in the phone system such that one could get calls that weren’t intended to get through, I wasn’t above doing that, but that was their problem, not mine.”

Still, the motive was exploration, not fraud, and it was considered bad form to profit illegally from these weird connections. Sometimes outsiders could not comprehend this. Samson’s roommates in the Burton Hall dorm, for instance, were nonhackers who thought it was all right to exploit system bugs without the holy justification of system exploration. After they pressured Samson for days, he finally gave in and handed them a 20-digit number that he said would access an exotic location. “You can dial this from the hall phone,” he told them, “but I don’t want to be around.” As they anxiously began dialing, Samson went to a downstairs phone, which rang just as he reached it. “This is the Pentagon,” he boomed in his most official voice. “What is your security clearance, please?” From the phone upstairs, Samson heard terrified gasps, and the click of a phone being hung up.

Network fingerprinting was obviously a pursuit limited to hackers, whose desire to know the system overruled any fear of getting nailed.

But as much as phone company esoterica fascinated Kotok, the prospect of the PDP-1 took precedence. Perhaps he sensed that nothing, even phone hacking, would be the same afterward. The people who designed and marketed this new machine were not your ordinary computer company button-downs. The company was a brand-new firm called Digital Equipment Corporation (DEC), and some of the TX-0 users knew that DEC’s first products were special interfaces made specifically for that TX-0. It was exciting enough that some of DEC’s founders had a view of computing that differed from the gray-flannel, batch-processed IBM mentality; it was positively breathtaking that the DEC people seemed to have looked at the freewheeling, interactive, improvisational, hands-on-über-alles style of the TX-0 community, and designed a computer that would reinforce that kind of behavior. The PDP-1 (the initials were short for Programmed Data Processor, a term considered less threatening than “computer,” which had all kinds of hulking-giant connotations) would become known as the first minicomputer, designed not for huge number-crunching tasks, but for scientific inquiry, mathematical formulation . . . and hacking. It would be so compact that the whole setup was no larger than three refrigerators—it wouldn’t require as much air conditioning, and you could even turn it on without a whole crew of sub-priests being needed to sequence several power supplies in the right order or start the time-base generator, among other exacting tasks. The retail price of the computer was an astoundingly low $120,000—cheap enough so people might stop complaining about how precious every second of computer time was. But the machine, which was the second PDP-1 manufactured (the first one was sold to the nearby scientific firm of Bolt Beranek and Newman, or BBN), cost MIT nothing: it was donated by DEC to the RLE lab.

So it was clear that hackers would have even more time on it than they did on the TX-0.

The PDP-1 would be delivered with a simple collection of systems software, which the hackers considered completely inadequate. The TX-0 hackers had become accustomed to the most advanced interactive software anywhere, a dazzling set of systems programs, written by hackers themselves and implicitly tailored to their relentless demands for control of the machine. Young Peter Deutsch, the twelve-year-old who had discovered the TX-0, had made good on his promise to write a spiffier assembler, and Bob Saunders had worked up a smaller, faster version of the FLIT debugger called Micro-FLIT. These programs had benefited from an expanded instruction set. One day, after considerable planning and designing by Saunders and Jack Dennis, the TX-0 had been turned off, and a covey of engineers exposed its innards and began hardwiring new instructions into the machine. This formidable task expanded the assembly language by several instructions. When the pliers and screwdrivers were put away and the computer carefully turned on, everyone madly set about revamping programs and bumming old programs using the new instructions.

The PDP-1 instruction set, Kotok learned, was not too different from that of the expanded TX-0, so Kotok naturally began writing systems software for the PDP-1 that very summer, using all the spare time he could manage. Figuring that everyone would jump in and begin writing as soon as the machine got there, he worked on a translation of the Micro-FLIT debugger so that writing the software for the “One” would be easier. Samson promptly named Kotok’s debugger “DDT,” and the name would stick, though the program itself would be modified countless times by hackers who wanted to add features or bum instructions out of it.

Kotok was not the only one preparing for the arrival of the PDP-1. Like a motley collection of expectant parents, other hackers were busily weaving software booties and blankets for the new baby coming into the family, so this heralded heir to the computing throne would be welcome as soon as it was delivered in late September.

The hackers helped bring the PDP-1 into its new home, the Kluge Room next door to the TX-0. It was a beauty: sitting behind a console half as long as the Tixo’s, you’d look at one compact panel of toggle switches and lights; next to that was the display screen, encased in a bright blue, six-sided, quasideco housing; behind it were the tall cabinets, the size of a refrigerator and three times as deep, with the wires, boards, switches, and transistors—entry to that, of course, was forbidden. There was a Flexowriter connected for online input (people complained about the noise so much that the Flexowriter was eventually replaced by a modified IBM typewriter, which didn’t work nearly so well) and a high-speed paper-tape reader, also for input. All in all, a downright heavenly toy.

Jack Dennis liked some of the software written by BBN for the prototype PDP-1, particularly the assembler. Kotok, though, felt like retching when he saw that assembler run—the mode of operation didn’t seem to fit the on-the-fly style he liked—so he and a few others told Dennis that they wanted to write their own. “That’s a bad idea,” said Dennis, who wanted an assembler up and running right away, and figured that it would take weeks for the hackers to do it.

Kotok and the others were adamant. This was a program that they’d be living with. It had to be just perfect. (Of course no program ever is, but that never stopped a hacker.)

“I’ll tell you what,” said Kotok, this twenty-year-old Buddha-shaped wizard, to the skeptical yet sympathetic Jack Dennis, “If we write this program over the weekend and have it working, would you pay us for the time?”

The pay scale at that time was such that the total would be something under five hundred dollars. “That sounds like a fair deal,” said Dennis,

Kotok, Samson, Saunders, Wagner, and a couple of others began on a Friday night late in September. They figured they would work from the TX-0 assembler that Dennis had written the original of and that twelve-year-old Peter Deutsch, among others, had revamped. They wouldn’t change inputs or outputs, and they wouldn’t redesign algorithms; each hacker would take a section of the TX-0 program and convert it to PDP-1 code. And they wouldn’t sleep. Six hackers worked around two hundred fifty man-hours that weekend, writing code, debugging, and washing down take-out Chinese food with massive quantities of Coca-Cola shipped over from the TMRC clubroom. It was a programming orgy, and when Jack Dennis came in that Monday, he was astonished to find an assembler loaded into the PDP-1, which, as a demonstration, was assembling its own code into binary.

By sheer dint of hacking, the TX-0—no, the PDP-1—hackers had turned out a program in a weekend that it would have taken the computer industry weeks, maybe even months to pull off. It was a project that would probably not be undertaken by the computer industry without a long and tedious process of requisitions, studies, meetings, and executive vacillating, most likely with considerable compromise along the way. It might never have been done at all. The project was a triumph for the Hacker Ethic.

The hackers were given even more access to this new machine than they had managed to get on the TX-0, and almost all of them switched their operations to the Kluge Room. A few stubbornly stuck to the Tixo, and to the PDP-1 hackers, this was grounds for some mild ridicule. To rub it in, the PDP-1 hackers developed a little demonstration based on the mnemonics of the instruction set of this bold new machine, which included such exotic instructions as DAC (Deposit Accumulator), LIO (Load Input-Output), DPY (Deplay), and JMP. The PDP-1 group would stand in a line and shout in unison:

When they chanted that last word—“Jump!”—they would all jump to the right. What was lacking in choreography was more than compensated for by enthusiasm: they were supercharged by the beauty of the machine, by the beauty of computers.

The same kind of enthusiasm was obvious in the even more spontaneous programming occurring on the PDP-1, ranging from serious systems programs, to programs to control a primitive robot arm, to whimsical hacks. One of the latter took advantage of a hacked-up connection between the PDP-1 and the TX-0—a wire through which information could pass, one bit at a time, between the two machines. According to Samson, the hackers called in the venerable AI pioneer John McCarthy to sit by the PDP-1. “Professor McCarthy, look at our new chess program!” And then they called another professor to sit by the TX-0. “Here’s the chess program! Type in your move!” After McCarthy typed his first move, and it appeared on the Flexowriter on the TX-0, the hackers told the other professor that he had just witnessed the TX-0’s opening move. “Now make yours!” After a few moves, McCarthy noticed that the computer was outputting the moves one letter at a time, sometimes with a suspicious pause between them. So McCarthy followed the wire to his flesh-and-blood opponent. The hackers rocked with mirth. But it would not be long before they would come up with programs for computers—no joke—to actually play tournament chess.

The PDP-1 beckoned the hackers to program without limit. Samson was casually hacking things like the Mayan calendar (which worked on a base-20 number system) and working overtime on a version of his TX-0 music program that took advantage of the PDP-1’s extended audio capabilities to create music in three voices—three-part Bach fugues, melodies interacting . . . computer music erupting from the old Kluge Room! The people at DEC had heard about Samson’s program and asked him to complete it on the PDP-1, so Samson eventually worked it so that someone could type a musical score into the machine by a simple translation of notes into letters and digits, and the computer would respond with a three-voice organ sonata. Another group coded up Gilbert and Sullivan operettas.

Samson proudly presented the music compiler to DEC to distribute to anyone who wanted it. He was proud that other people would be using his program. The team that worked on the new assembler felt likewise. For instance, they were pleased to have paper tape bearing the program in the drawer so anyone using the machine could access it, try to improve it, bum a few instructions from it, or add a feature to it. They felt honored when DEC asked for the program so it could offer it to other PDP-1 owners. The question of royalties never came up. To Samson and the others, using the computer was such a joy that they would have paid to do it. The fact that they were getting paid the princely sum of $1.60 an hour to work on the computer was a bonus. As for royalties, wasn’t software more like a gift to the world, something that was reward in itself? The idea was to make a computer more usable, to make it more exciting to users, to make computers so interesting that people would be tempted to play with them, explore them, and eventually hack on them. When you wrote a fine program you were building a community, not churning out a product.

Anyway, people shouldn’t have to pay for software—information should be free!

The TMRC hackers were not the only ones who had been devising plans for the new PDP-1. During that summer of 1961, a plan for the most elaborate hack yet—a virtual showcase of what could come out of a rigorous application of the Hacker Ethic—was being devised. The scene of these discussions was a tenement building on Higham Street in Cambridge, and the original perpetrators were three itinerant programmers in their mid-twenties who’d been hanging around various computation centers for years. Two of the three lived in the tenement, so in honor of the pompous proclamations emanating from nearby Harvard University the trio mockingly referred to the building as the Higham Institute.

One of the Fellows of this bogus institution was Steve Russell, nicknamed, for unknown reasons, Slug. He had that breathless chipmunk speech pattern so common among hackers, along with thick glasses, modest height, and a fanatic taste for computers, bad movies, and pulp science fiction. All three interests were shared by the resident attendees at those bull sessions on Higham Street.

Russell had long been a “coolie” (to use a TMRC term) of Uncle John McCarthy. McCarthy had been trying to design and implement a higher-level language that might be sufficient for artificial intelligence work. He thought he had found it in LISP. The language was named for its method of List Processing; by simple yet powerful commands, LISP could do many things with few lines of code; it could also perform powerful recursions—references to things within itself—which would allow programs written in that language to actually “learn” from what happened as the program ran. The problem with LISP at that time was that it took up an awful amount of space on a computer, ran very slowly, and generated voluminous amounts of extra code as the programs ran, so much so that it needed its own "garbage collection" program to periodically clean out the computer memory.

Russell was helping Uncle John write a LISP interpreter for the Hulking Giant IBM 704. It was, in his words, “a horrible engineering job,” mostly due to the batch-processing tedium of the 704.

Compared to that machine, the PDP-1 looked like the Promised Land to Slug Russell. More accessible than the TX-0, and no batch processing! Although it didn’t seem big enough to do LISP, it had other marvelous capabilities, some of which were objects of discussion of the Higham Institute. What particularly intrigued Russell and his friends was the prospect of making up some kind of elaborate “display hack” on the PDP-1, using the CRT screen. After considerable midnight discourse, the three-man Higham Institute put itself on record as insisting that the most effective demonstration of the computer’s magic would be a visually striking game.

There had been several attempts to do this kind of thing on the TX-0. One of them was a hack called Mouse in the Maze—the user first constructed a maze with the light pen, and a blip on the screen representing a mouse would tentatively poke its way through the maze in search of another set of blips in the shape of cheese wedges. There was also a “VIP version” of the game, in which the mouse would seek martini glasses. After it got to the glass, it would seek another, until it ran out of energy, too drunk to continue. When you flicked the switches to run the mouse through the maze a second time, though, the mouse would “remember” the path to the glasses, and like an experienced barfly would unhesitatingly scurry toward the booze. That was as far as display hacks would go on the TX-0.

But already on the PDP-1, which had a screen that was easier to program than the TX-0’s, there had been some significant display hacks. The most admired effort was created by one of the twin gurus of artificial intelligence at MIT, Marvin Minsky (the other one was, of course, McCarthy). Minsky was more outgoing than his fellow AI guru, and more willing to get into the hacker mode of activity. He was a man with very big ideas about the future of computing—he really believed that one day machines would be able to think, and he would often create a big stir by publicly calling human brains “meat machines,” implying that machines not made of meat would do as well some day. An elfish man with twinkling eyes behind thick glasses, a starkly bald head, and an omnipresent turtleneck sweater, Minsky would say this with his usual dry style, geared simultaneously to maximize provocation and to leave just a hint that it was all some cosmic goof—of course machines can’t think, heh-heh. Marvin was the real thing; the PDP-1 hackers would often sit in on his course, Intro to AI 6.544, because not only was Minsky a good theoretician, but he knew his stuff. By the early 1960s, Minsky was beginning to organize what would come to be the world’s first laboratory in artificial intelligence; and he knew that to do what he wanted, he would need programming geniuses as his foot soldiers—so he encouraged hackerism in any way he could.

One of Minsky’s contributions to the growing canon of interesting hacks was a display program on the PDP-1 called the Circle Algorithm. It was discovered by mistake, actually—while trying to bum an instruction out of a short program to make straight lines into curves or spirals, Minsky inadvertently mistook a “Y” character for a “Y prime,” and instead of the display squiggling into inchoate spirals as expected, it drew a circle: an incredible discovery, which was later found to have profound mathematical implications. Hacking further, Minsky used the Circle Algorithm as a stepping-off point for a more elaborate display in which three particles influenced each other and made fascinating, swirling patterns on the screen, self-generating roses with varying numbers of leaves. “The forces particles exerted on others were totally outlandish,” Bob Wagner later recalled. “You were simulating a violation of natural law!” Minsky called the hack a "Tri-Pos: Three-Position Display" program, but the hackers affectionately renamed it the Minskytron.

Slug Russell was inspired by this. At the Higham Institute sessions some months back, he and his friends had discussed the criteria for the ultimate display hack. Since they had been fans of trashy science fiction, particularly the space opera novels of E.E. “Doc” Smith, they somehow decided that the PDP-1 would be a perfect machine to make a combination grade-B movie and $120,000 toy. A game in which two people could face each other in an outer-space showdown. A Higham Institute Study Group on Space Warfare was duly organized, and its conclusion strongly implied that Slug Russell should be the author of this historic hack.

But months later, Russell hadn’t even started. He would watch the Minskytron make patterns, he’d flip switches to see new patterns develop, and every so often he’d flip more switches when the program got wedged into inactivity. He was fascinated, but thought the hack too abstract and mathematical. “This demo is a crock,” he finally decided—only thirty-two or so instructions, and it didn’t really do anything.

Slug Russell knew that his war-in-outer-space game would do something. In its own kitschy, sci-fi terms, it would be absorbing in a way no previous hack had ever been. The thing that got Slug into computers in the first place was the feeling of power you got from running the damn things. You can tell the computer what to do, and it fights with you, but it finally does what you tell it to. Of course it will reflect your own stupidity, and often what you tell it to do will result in something distasteful. But eventually, after tortures and tribulations, it will do exactly what you want. The feeling you get then is unlike any other feeling in the world. It can make you a junkie. It made Slug Russell a junkie, and he could see that it had done the same thing to the hackers who haunted the Kluge Room until dawn. It was that feeling that did it, and Slug Russell guessed the feeling was power.

Slug got sort of a similar, though less intense, feeling from Doc Smith’s novels. He let his imagination construct the thrill of roaring across space in a white rocket ship . . . and wondered if that same excitement could be captured while sitting behind the console of the PDP-1. That would be the Spacewar he dreamed about. Once again he vowed to do it.

Later.

Slug was not as driven as some of the other hackers. Sometimes he needed a push. After he made the mistake of opening up his big mouth about this program he was going to write, the PDP-1 hackers, always eager to see another hack added to the growing pile of paper tapes in the drawer, urged him to do it. After mumbling excuses for a while, he said he would, but he’d first have to figure out how to write the elaborate sine-cosine routines necessary to plot the ships’ motion.

Kotok knew that hurdle could be easily solved. Kotok at that point had been getting fairly cozy with the people at DEC, several miles away at Maynard. DEC was informal, as computer manufacturers went, and did not regard MIT hackers as the grungy, frivolous computer-joyriders that IBM might have taken them for. For instance, one day when a piece of equipment was broken, Kotok called up Maynard and told DEC about it; they said, “Come up and get a replacement.” By the time Kotok got up there, it was well after 5 P.M. and the place was closed. But the night watchman let him go in, find the desk of the engineer he’d been talking to, and root through the desk until he found the part. Informal, the way hackers like it. So it was no problem for Kotok to go up to Maynard one day, where he was positive someone would have a routine for sine and cosine that would run on the PDP-1. Sure enough, someone had it, and since information was free, Kotok took it back to Building 26.

“Here you are, Russell,” Kotok said, paper tapes in hand. “Now what’s your excuse?”

At that point, Russell had no excuse. So he spent his off-hours writing this fantasy PDP-1 game, the likes of which no one had seen before. Soon he was spending his “on” hours working on the game. He began in early December, and when Christmas came, he was still hacking. When the calendar wrapped around to 1962, he was still hacking. By that time, Russell could produce a dot on the screen that you could manipulate: by flicking some of the tiny toggle switches on the control panel, you could make the dots accelerate and change direction.

He then set about making the shapes of the two rocket ships: both were classic cartoon rockets, pointed at the top and blessed with a set of fins at the bottom. To distinguish them from each other, he made one chubby and cigar-shaped, with a bulge in the middle, while the second he shaped like a thin tube. Russell used the sine and cosine routines to figure out how to move those shapes in different directions. Then he wrote a subroutine to shoot a “torpedo” (a dot) from the rocket nose with a switch on the computer. The computer would scan the position of the torpedo and the enemy ship; if both occupied the same area, the program would call up a subroutine that replaced the unhappy ship with a random splatter of dots representing an explosion. (That process was called “collision detection.”)

All of this was actually a significant conceptual step toward more sophisticated “real-time” programming, where what happens on a computer matches the frame of reference in which human beings are actually working. In another sense, Russell was emulating the online, interactive debugging style that the hackers were championing—the freedom to see what instruction your program stopped dead on, and to use switches or the Flexowriter to jimmy in a different instruction, all while the program was running along with the DDT debugger. The game Spacewar, a computer program itself, helped show how all games—and maybe everything else—worked like computer programs. When you went a bit astray, you modified your parameters and fixed it. You put in new instructions. The same principle applied to target shooting, chess strategy, and MIT course work. Computer programming was not merely a technical pursuit, but an approach to the problems of living.

In the later stages of programming, Saunders helped Slug Russell out, and they hacked a few intense six-to-eight-hour sessions. Sometime in February, Russell unveiled the basic game. There were the two ships, each with thirty-one torpedoes. There were a few random dots on the screen representing stars in this celestial battlefield. You could maneuver the ships by flicking four switches on the console of the PDP-1, representing clockwise turn, counterclockwise turn, accelerate, and fire torpedo.

Slug Russell knew that by showing a rough version of the game, and dropping a paper tape with the program into the box with the PDP-1 system programs, he was welcoming unsolicited improvements. Spacewar was no ordinary computer simulation—you could actually be a rocket-ship pilot. It was Doc Smith come to life. But the same power that Russell had drawn on to make his program—the power that the PDP-1 lent a programmer to create his own little universe—was also available to other hackers, who naturally felt free to improve Slug Russell’s universe. They did so instantly.

The nature of the improvements might be summed up by the general hacker reaction to the original routine Slug Russell used for his torpedoes. Knowing that military weapons in real life aren’t always perfect, Russell figured that he’d make the torpedoes realistic. Instead of having them go in a straight line until they ran out of steam and exploded, he put in some random variations in the direction and velocity. Instead of appreciating this verisimilitude, the hackers denounced it. They loved smooth-running systems and reliable tools, so the fact that they would be stuck with something that didn’t work right drove them crazy. Russell later figured out that “weapons or tools that aren’t very trustworthy are held in very low esteem—people really like to be able to trust their tools and weapons. That was very clear in that case.”

But of course that could be easily fixed. The advantage that a world created by a computer program had over the real world was that you could fix a dire problem like faulty torpedoes just by changing a few instructions. That was why so many people found it easy to lose themselves in hackerism in the first place! So the torpedoes were fixed, and people spent hours in outer-space dueling. And even more hours trying to make the Spacewar world a better one.

Peter Samson, for instance, loved the idea of Spacewar, but could not abide the randomly generated dots that passed themselves off as the sky. Real space had stars in specific places. “We’ll have the real thing,” Samson vowed. He obtained a thick atlas of the universe, and set about entering data into a routine he wrote that would generate the actual constellations visible to someone standing on the equator on a clear night. All stars down to the fifth magnitude were represented; Samson duplicated their relative brightness by controlling how often the computer lit the dot on the screen which represented the star. He also rigged the program so that, as the game progressed, the sky would majestically scroll—at any one time the screen exposed forty-five percent of the sky. Besides adding verisimilitude, this “Expensive Planetarium” program also gave rocket fighters a mappable background from which to gauge position. The game could truly be called, as Samson said, Shootout-at-El-Cassiopeia.

Another programmer, named Dan Edwards, was dissatisfied with the unanchored movement of the two dueling ships. It made the game merely a test of motor skills. He figured that adding a gravity factor would give the game a strategic component. So he programmed a central star—a sun—in the middle of the screen; you could use the sun’s gravitational pull to give you speed as you circled it, but if you weren’t careful and got too close, you’d be drawn into the sun, which was certain death.

Before all the strategic implications of this variation could be employed, Shag Garetz, one of the Higham Institute trio, contributed a wild-card type of feature. He had read in Doc Smith’s novels how space hot-rodders could suck themselves out of one galaxy and into another by virtue of a "hyper-spatial tube,” which would throw you into “that highly enigmatic Nth space.” So he added a “hyperspace” capability to the game, allowing a player to avoid a dire situation by pushing a panic button that would zip him to this hyperspace. You were allowed to go into hyperspace three times in the course of a game; the drawback was that you never knew where you might come out. Sometimes you’d reappear right next to the sun, just in time to see your ship hopelessly pulled to an untimely demise on the sun’s surface. In tribute to Marvin Minsky’s original hack, Garetz programmed the hyperspace feature so that a ship entering hyperspace would leave a “warp-induced photonic stress emission signature”—a leftover smear of light in a shape that often formed in the aftermath of a Minskytron display.

The variations were endless. By switching a few parameters you could turn the game into “hydraulic spacewar,” in which torpedoes flow out in ejaculatory streams instead of one by one. Or, as the night grew later and people became locked into interstellar mode, someone might shout, “Let’s turn on the Winds of Space!” and someone would hack up a warping factor, which would force players to make adjustments every time they moved. Though any improvement a hacker wished to make would be welcome, it was extremely bad form to make some weird change in the game unannounced. The effective social pressures that enforced the Hacker Ethic—which urged hands-on for improvement, not damage—prevented any instance of that kind of mischief. Anyway, the hackers were already engaged in a mind-boggling tweak of the system—they were using an expensive computer to play the world’s most glorified game!

Spacewar was played a hell of a lot. For some, it was addictive. Though no one could officially sign up the PDP-1 for a Spacewar session, the machine’s every free moment that spring seemed to have some version of the game running. Bottles of Coke in hand (and sometimes with money on the line), the hackers would run marathon tournaments. Russell eventually wrote a subroutine that would keep score, displaying in octal (everyone could sight-read that base-eight number system by then) the total of games won. For a while, the main drawback seemed to be that working the switches on the console of the PDP-1 was uncomfortable—everybody was getting sore elbows from keeping their arms at that particular angle. So one day Kotok and Saunders went over to the TMRC clubroom and found parts for what would become the first computer joysticks. Constructed totally with parts lying around the clubroom and thrown together in an hour of inspired construction, the control boxes were made of wood, with Masonite tops. They had switches for rotation and thrust, as well as a button for hyperspace. All controls were, of course, silent, so that you could surreptitiously circle around your opponent or duck into Nth space, should you care to.

While some hackers lost interest in Spacewar once the fury of the programming phase had died down, others developed a killer instinct for devising strategies to mow down opponents. Most games were won and lost in the first few seconds. Wagner became adept at the “lie in wait” strategy, in which you stayed silent while gravity whipped you around the sun, then straightened out and began blasting torps at your opponent. Then there was a variation called the "CBS Opening,” where you angled to shoot and then whipped around the star: the strategy got its name because when both Spacewar gladiators tried it, they would leave a pattern on the screen that bore a remarkable resemblance to the CBS eye. Saunders, who took his Spacewar seriously, used a modified CBS strategy to maintain dominance through the tournaments—there was a time when he couldn’t be beaten. However, after twenty minutes of protecting your place in the king-of-the-hill-structured contest, even a master Spacewarrior would get a bit blurry-eyed and slower on the draw, and most everybody got a chance to play Spacewar more than was probably sensible. Peter Samson, second only to Saunders in Spacewarring, realized this one night when he went home to Lowell. As he stepped out of the train, he stared upward into the crisp, clear sky. A meteor flew overhead. Where’s the spaceship? Samson thought as he instantly swiveled back and grabbed the air for a control box that wasn’t there.

In May 1962, at the annual MIT Open House, the hackers fed the paper tape with twenty-seven pages worth of PDP-1 assembly-language code into the machine, set up an extra display screen—actually a giant oscilloscope—and ran Spacewar all day to a public that drifted in and could not believe what they saw. The sight of it—a science-fiction game written by students and controlled by a computer—was so much on the verge of fantasy that no one dared predict that an entire genre of entertainment would eventually be spawned from it.

It wasn’t until years later, when Slug Russell was at Stanford University, that he realized that the game was anything but a hacker aberration. After working late one night, Russell and some friends went to a local bar that had some pinball machines. They played until closing time; then, instead of going home, Russell and his coworkers went back to their computer, and the first thing his friends did was run Spacewar. Suddenly it struck Russell: “These people just stopped playing a pinball machine and went to play Spacewar—by gosh, it is a pinball machine.” The most advanced, imaginative, expensive pinball machine the world had seen.

Like the hackers’ assemblers and the music program, Spacewar was not sold. Like any other program, it was placed in the drawer for anyone to access, look at, and rewrite as they saw fit. The group effort that stage by stage had improved the program could have stood for an argument for the Hacker Ethic: an urge to get inside the workings of the thing and make it better had led to measurable improvement. And of course it was all a huge amount of fun. It was no wonder that other PDP-1 owners began to hear about it, and the paper tapes holding Spacewar were freely distributed. At one point the thought crossed Slug Russell’s mind that maybe someone should be making money from this, but by then there were already dozens of copies circulating. DEC was delighted to get a copy, and the engineers there used it as a final diagnostic program on PDP-1s before they rolled them out the door. Then, without wiping the computer memory clean, they’d shut the machine off. The DEC sales force knew this, and often, when machines were delivered to new customers, the salesman would turn on the power, check to make sure no smoke was pouring out the back, and hit the “VY” location where Spacewar resided. And if the machine had been carefully packed and shipped, the heavy star would be in the center, and the cigar-shaped rocket and the tube-shaped rocket would be ready for cosmic battle. A maiden flight for a magic machine.

Spacewar, as it turned out, was the lasting legacy of the pioneers of MIT hacking. In the next couple of years many of the TX-0 and PDP-1 joyriders departed the Institute. Saunders would take a job in industry at Santa Monica (where he would later write a Spacewar for the PDP-7 he used at work). Bob Wagner went off to the Rand Corporation. Peter Deutsch went to Berkeley, to begin his freshman year of college. Kotok took a part-time job that developed into an important designing position at DEC (though he managed to hang around TMRC and the PDP-1 for years afterward). In a development that was to have considerable impact on spreading MIT-style hackerism outside of Cambridge, John McCarthy left the Institute to begin a new artificial intelligence lab on the West Coast, at Stanford University. Slug Russell, ever McCarthy’s LISP-writing coolie, tagged along.

But new faces and some heightened activity in the field of computing were to insure that the hacker culture at MIT would not only continue, but thrive and develop more than ever. The new faces belonged to breathtakingly daring hackers destined for word-of-mouth, living-legend fame. But the developments that would allow these people to take their place in living the hacker dream were already under way, initiated by people whose names would become known by more conventional means: scholarly papers, academic awards, and, in some cases, notoriety in the scientific community.

These people were the planners. Among them were scientists who occasionally engaged in hacking—Jack Dennis, McCarthy, Minsky—but who were ultimately more absorbed by the goals of computing than addicted to the computing process. They saw computers as a means to a better life for the human race, but did not necessarily think that working on a computer would be the key element in making that life better.

Some of the planners envisioned a day when artificially intelligent computers would relieve man’s mental burdens, much as industrial machinery had already partially lifted his physical yoke. McCarthy and Minsky were the vanguard of this school of thought, and both had participated in a 1956 Dartmouth conference that established a foundation for research in this field. McCarthy’s work in the higher-level language LISP was directed toward this end, and was sufficiently intriguing to rouse hackers like Slug Russell, Peter Deutsch, Peter Samson, and others into working with LISP. Minsky seemed interested in artificial intelligence with a more theoretical basis: a gleeful, bald-headed Johnny Appleseed in the field, he would spread his seeds, each one a thought capable of blooming into a veritable apple tree of useful AI techniques and projects.

The planners were also extremely concerned about getting the power of computers into the hands of more researchers, scientists, statisticians, and students. Some planners worked on making computers easier to use; John Kemeny of Dartmouth showed how this could be done by writing an easier-to-use computer language called BASIC. Programs written in BASIC ran much slower than assembly language and took up more memory space, but did not require the almost monastic commitment that machine language demanded. MIT planners concentrated on extending actual computer access to more people. There were all sorts of justifications for this, not the least being the projected scale of economy—one that was glaringly preferable to the then current system, in which even seconds of computer time were valuable commodities (though you would not know it around the Spacewar-playing PDP-1. If more people used computers, more expert programmers and theoreticians would emerge, and the science of computing—yes, these aggressive planners were calling it a science—could only benefit by that new talent. But there was something else involved in this. It was something any hacker could understand—the belief that computing, in and of itself, was positive. John McCarthy illustrated that belief when he said that the natural state of man was to be online to a computer all the time. “What the user wants is a computer that he can have continuously at his beck and call for long periods of time.”

The man of the future. Hands on a keyboard, eyes on a CRT, in touch with the body of information and thought that the world had been storing since history began. It would all be accessible to Computational Man.

None of this would occur with the batch-processed IBM 704. Nor would it occur with the TX-0 and PDP-1, with their weekly log sheets completely filled in within hours of being posted on the wall. No, in order to do this, you’d have to have several people use the computer at once. (The thought of each person having his or her own computer was something only a hacker would think worthwhile.) This multiuser concept was called time sharing, and in 1960 the heaviest of the MIT planners began the Long-Range Computer Study Group. Among the members were people who had watched the rise of the MIT hacker with amusement and assent, people like Jack Dennis, Marvin Minsky, and Uncle John McCarthy. They knew how important it was for people to actually get their hands on those things. To them, it was not a question of whether to time-share or not, it was a question of how to do it.

Computer manufacturers, particularly IBM, were not enthusiastic. It was clear that MIT would have to go about it pretty much on its own. (The research firm of Bolt Beranek and Newman was also working on time sharing.) Eventually two projects began at MIT: one was Jack Dennis’ largely solo effort to write a time-sharing system for the PDP-1. The other was undertaken by a professor named F.J. Corbató, who would seek some help from the reluctant goliath, IBM, to write a system for the 7090.

The Department of Defense, especially through its Advanced Research Projects Agency (ARPA), had been supporting computers since the war, mindful of their eventual applications toward military use. So by the early sixties, MIT had obtained a long-range grant for its time-sharing project, which would be named Project MAC (the initials stood for two things: Multiple Access Computing, and Machine Aided Cognition). Uncle Sam would cough up three million dollars a year. Dennis would be in charge. Marvin Minsky would also be a large presence, particularly in using the one-third share of the money that would go not for time-sharing development, but for the still ephemeral field of artificial intelligence. Minsky was delighted, since the million dollars was ten times his previous budget for AI, and he realized that a good part of the remaining two thirds would see its way into AI activities as well. It was a chance to set up an ideal facility, where people could plan for the realization of the hacker dream with sophisticated machines, shielded from the bureaucratic lunacy of the outside world. Meanwhile, the hacker dream would be lived day-by-day by devoted students of the machine.

The planners knew that they’d need special people to staff this lab. Marvin Minsky and Jack Dennis knew that the enthusiasm of brilliant hackers was essential to bring about their Big Ideas. As Minsky later said of his lab: “In this environment there were several things going on. There were the most abstract theories of artificial intelligence that people were working on and some of [the hackers] were concerned with those, most weren’t. But there was the question of how do you make the programs that do these things and how do you get them to work.”

Minsky was quite happy to resolve that question by leaving it to the hackers, the people to whom “computers were the most interesting thing in the world.” The kind of people who, for a lark, would hack up something even wilder than Spacewar and then, instead of playing it all night (as sometimes was happening in the Kluge Room), would hack some more. Instead of space simulations, the hackers who did the scut work at Project MAC would be tackling larger systems—robotic arms, vision projects, mathematical conundrums, and labyrinthine time-sharing systems that boggled the imagination. Fortunately, the classes that entered MIT in the early sixties were to provide some of the most devoted and brilliant hackers who ever sat at a console. And none of them so fully fit the title “hacker” as Richard Greenblatt.