How Computer Games Ate Our Quarters, Won Our Hearts and Rewired
By J.C. Herz
Little, Brown, 1997
In the fall of 1961, a large, rectangular box landed on MIT's doorstep. It came from the Digital Equipment Corporation. The box contained DEC's new model computer, the PDP-1, and its manufacturers hoped that MIT's electrical engineering department would do something interesting with it--win the space race, breed artificially intelligent robots, or at least revolutionize information processing for the greater glory of corporate America. Within a year, the computing pioneers at MIT had done none of these things.
But one of them had written the world's first videogame.
It was a two-player game of dueling spaceships firing photon torpedoes against a field of electronic stars. Steve Russell, the Promethean figure in videogame lore, wrote it. And in the spirit of the Atomic Age, he dubbed it Spacewar. This was the ur-videogame, programmed on the first computer to use a real screen and a typewriter instead of endless stacks of paper punch cards.
Thirty-five years have gone by. Computer power has increased by a factor of thousands. Punch cards have given way to magnetic tape, floppy disks, and CD-ROMs. Steve Russell has gotten older and gruffer and now manages programmers in Silicon Valley instead of tinkering with artificial intelligence code in Cambridge, Massachusetts. But he recalls the PDP-1 with the brio of a young grad student.
"It was the size of about three refrigerators, and it had an old-fashioned computer console with a whole bunch of switches and lights," he says, like he's describing a superdeluxe toy that just arrived on Christmas morning. "And it had a cathode ray tube, and it had a typewriter. I thought this was a great thing, and I was itching to get my fingers on it and try it. And so a bunch of us--some people who'd worked on the debugger and some friends of mine from Harvard--we started talking about how you could really do a lot more with the computer and the display. Space was very hot at the time--it was just when satellites were getting up and we were talking about putting a man on the moon. So we said, gee, space is fun, and most people don't appreciate how to maneuver things in space. And so I wrote a demo program that had two spaceships that were controlled by the switches on the computer. They were different shapes. They could fire torpedoes at one another, and they could navigate around the screen with the sort of physics you find in space. And then Pete Samson wrote a program called Expensive Planetarium." There were, he explains, a whole family of "Expensive" programs on the PDP-1, at a time when even the most rudimentary computer tasks required massive outlays of manpower and federal grant money. "There was Expensive Typewriter, which did just what a typewriter did, except it was much more expensive, and there was Expensive Desk Calculator, which was something similar. Expensive Planetarium displayed the star map sort of as you'd see it looking out the window, and I incorporated that as a background. And then Dan Edwards looked at my code for displaying outlines and figured out a way to speed it up by a factor of two or three, which gave him enough time to compute the effect of gravity on the two spaceships. And that made it a much better game, because with the stars in the background, you could estimate the motion of the ships much better than when they were just on a dead black background. And with the spaceships affected by gravity, it made it a bit of a challenge, and you got to try to do orbital mechanics--there was the star in the center of the screen, and it attracted them just as the sun would."
At first, Russell and his band of console cosmonauts used the PDP's row of tabletop toggle switches as game controllers. "You had four controls," Russell recalls, "rotate counterclockwise, rotate clockwise, turn on your rocket thrust, which caused a little tail of rocket exhaust to show on the screen, and torpedo. The torpedoes were proximity-fused, so that when they got close to something they blew up. If it was another torpedo, they both blew up, and if it was another spaceship, they both blew up. So it would work as a defensive weapon, because you could blow other torpedoes out of the sky if they were coming at you. But we very quickly found that your elbows got tired, because the table was hard and not quite at a convenient height. So we and many other people hooked up controllers which were basically four buttons in a row that you could control your spaceship with." The ur-joypad.
Working on Spacewar on study breaks, Russell and his friends polished up and completed the game in the spring of 1962. He remembers wondering whether maybe there might be some way to commercialize this thing and make some money. After thinking hard for about a week, he concluded that no one would pay for it. So he left the program on all the nearby computers so that anyone could play it or copy it. A few people did. And if anyone asked, Russell and his friends gave out the source code.
Of course, the handful of people that copied Spacewar off MIT's PDP-1 gave it to their colleagues, who shared it with their students, who spread it among their fellow programmers, until, by the mid-sixties, there was a copy of Spacewar on every research computer in America, as well as hundreds of personal variations on the source code and millions of dollars of lost-time cost to academia and the military-industrial complex. In this way, Spacewar foreshadowed the virulent spread of Doom across computer networks thirty years later. Spacewar was so pervasive that it's hard to overestimate its impact upon the computer culture of the time. Virtually every young programmer in the sixties played it. For some, Spacewar was their very first glimpse of a computer. "What happened," says Russell, "was that most of the people who had access to the PDP-1 would show their family and friends what they were doing and they would demonstrate with Spacewar, because it was more interesting than watching someone debug a program with DDT.
"Actually," he muses, "I think the thing I take the most pride in about Spacewar is that it got so many people hooked on computer programming. It caught a lot of eyes and got a lot of interesting people asking, `How do you do that?'"
Thus initiated, a good number of those people went on to become software barons. And looking back, it wasn't powerful algorithms or lines of data-crunching code that lured them into computing. It was a primitive yet strangely compelling game, two little spaceships on a screen shooting bullets at each other--electronic dodgeball. It was the human drive to play, even on a hulking PDP-1. Russell, now revered as the granddaddy of videogames, was the first into the lake. But, he admits, "If I hadn't done it, someone would've done something equally exciting if not better in the next six months. I just happened to get there first." The advent of computer games was foretold in the stars of Expensive Planetarium. They were inescapable, because the impulse to convert million-dollar calculators into intellectual jungle gyms was simply too great.
And so as early computers propagated, so did the binary code that turned them into hugely expensive game machines. By the early seventies, a handful of antediluvian videogames were competing for precious computer processing cycles on academic mainframes. These proto-games were tiny and simple; they were to Wing Commander V what dinoflagellates are to a humpback whale. But in these primeval scraps of game code, you could catch a glimpse of much more powerful, complicated videogames to come.
Lunar Lander, for example, was an early mainframe game that challenged you to land a rocket pod on the surface of the moon. There were no game controllers. There wasn't even a screen. All this game did was print out successive lines of text in time-sequence turns. Each turn would tell you what your velocity was, how far above the lunar surface you were, and how much fuel you had left. You then had to choose the amount of rocket thrust for the next turn. The more thrust you used, the slower you descended--and the more fuel you used. If you decelerated too quickly, using too much thrust too early, you would run out of fuel and drop the rest of the way. If you waited too long to slow down, you couldn't decelerate in time to make a safe landing and crashed to bits on the lunar surface. Basically, you had to jigger it so that your distance to the surface fell to zero while your velocity was very low. All of this was calculated on a PDP computer using simple physics equations. That was it. That was the game. But Lunar Lander was, arguably, the first recreational aircraft simulator.
Another early game, sometimes called Hammurabi, sometimes called Kingdom, was fifty lines of BASIC code that crudely simulated a feudal domain. The game ran in yearlong cycles, and for each year you would tell it how many acres of grain you wanted to plant, what your tax rate was going to be, and a few authoritarian central planning fiats. The computer would run through its calculations like the imperious processors in a Douglas Adams novel and, after much humming and spinning, spit out the consequences for your digital terrarium. If your tax rate was low and there was excess food, for instance, then more people would come into the kingdom and the population would increase. But if the population was too high and there wasn't enough food, there'd be famine and people would die or move out. The object was to build up the kingdom and increase the population. Basically, Hammurabi is a distant ancestor of all the kingdom-building strategy games that involve infrastructure and political trade-offs, SimCity being the most illustrious descendant.
The wriggling protoplasm of dungeons-and-dragons tunnel adventure games was the legendary Hunt the Wumpus, a mainframe program so antique that just confirming its existence was a challenge. This program is the Loch Ness Monster of videogames, always receding into the mists of hacker history before it can be properly identified. Dozens of videogame designers had heard of Hunt the Wumpus but mumbled when I pressed for specifics. None actually knew what it was about. After countless dead ends and false leads, the trail of the elusive Wumpus led finally to Walt Freitag, a human Baedeker of videogame lore who now designs CD-ROMs for Byron Preiss Multimedia and lectures, with a Victorian professor's stamina and in Dickensian detail, about videogame theory and apocrypha.
"Ah yes," he says. "Hunt the Wumpus. Hunt the Wumpus was another one of these fifty-line BASIC programs, although this one was more like two hundred lines. It was a network of tunnels and nodes. And I believe the actual geometry of the network was a dodecahedron. So there were twenty vertices with three tunnels coming to each node. You had to choose a tunnel and go down it--this was all done in text--and it would print out: `You are at node three. Move or shoot.' And you could shoot down a tunnel to any of the adjacent nodes, and if the Wumpus was there, you would kill it. But if you moved down the tunnel to where the Wumpus was, the Wumpus would kill you. There was also a warning if you were in a node adjacent to the Wumpus. It would print a little message that said: `You are in node 5. I smell a Wumpus. Move or shoot.' And you had some limited number of shots, and if you ran out of shots, you would lose. There were also some bats, and if you were adjacent to where there were bats, it would say: `I smell bats.' And the bats would randomly carry you to another node."
Hunt the Wumpus flickered briefly as a computer game phenomenon, then faded. Like some australopithecine also-ran, it was superseded by a more robust contemporary, the legendary Adventure mainframe game of 1967. Originally known as ADVENT (file names maxed out at six letters), Adventure was the ur-sword-and-sorcery game, just as Spacewar was the ur-shooter. The object: explore subterranean caves, fight monsters, plunder storerooms for treasure, et cetera. Adventure was a logical extension of the fantasy role-playing games that suffused hackerdom, spawning cultish extracurricular organizations like the Society for Creative Anachronism. A high percentage of computer programmers were and are, not surprisingly, Dungeons & Dragons aficionados. There's an affinity between computer programming and games that require reams of graph paper and twenty-sided dice. Both are artificial universes governed by quantifiable rules, probability, and obsessive mapping. Charting out subterranean passages and dead ends is pretty much analogous to mapping out a circuit or debugging a piece of code. So a combination of computers and dragon-slashing games was begging to happen. Adventure not only took care of the scorekeeping and referee chores, but its bone-dry humor and exploratory conventions influenced a generation of game programmers. In Adventure and its descendants, the emphasis was on puzzle solving and getting to some mysterious end at a slow, novelistic pace. In terms of genre and gameplay, it was a straight shot to Myst.
But then, most of the videogames we love trace their roots back to these cloistered computer games. If you look at Asteroids, it's hard not to catch a whiff of Spacewar. The resemblance is obvious. What was not obvious at the time was how or if these games would ever escape the rarefied atmosphere of electrical engineering departments. When these programs were written, computers were incredibly large and expensive. Even a game that resided on every PDP-1 on earth would still only be seen by a few thousand people. Everyone agreed that Spacewar and Lunar Lander and Adventure were incredibly cool. But no one could imagine computers cheap enough to make them a mass phenomenon.
It took a long time for the computing power to get cheap enough. Not a long time in the normal historical scale. But ten years, in the computer universe, is a geologic era riven by massive earthquakes, volcanic explosions, and tectonic shifts. "I haven't done a precise back-of-the-envelope calculation on this," says Russell, "but when we do our games now, you don't consider things that work on a computer with less than 20 million instructions per second. Well, the PDP-1 was 30,000 instructions per second, and they sold fifty of them, so that's more than all the PDP-1s in the world. And that's the standard consumer product."
But even given the massive leaps in technology, when he programmed Spacewar, did he have any idea what he had done? That he'd invented, you know, videogames?
"No. Not until years later, when I was working at Stanford. We had a PDP-1, and as was customary for PDP-1s there was a copy of Spacewar on the console. One day, we had been working late, and we went up the street to the local bar, had some hamburgers and beer and sat around and talked. And I had to go back and get something from the computer lab, so I went back after they closed. And lo and behold, here were a couple of Stanford students who had been playing pinball back at the Oasis, and they had gone in and were playing Spacewar on the PDP-1. And I said, `Aw, I guess it is sort of a pinball machine.' That was the first time I really was conscious that that was what I had done."
(C) 1997 J. C. Herz
All rights reserved.
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