Three inventors of Spacewar play the game

Creators Alan Kotok, Steve Russell and J.M. Graetz play a game of Spacewar!

Spacewar! - It Came From MIT

Hingham Institute/MIT 1962

Wedge vs. Needle

At MIT in 1961, in a ramshackle structure shaped like a drunk’s version of the letter ‘E’ named Building 20  – initially built during WWII as a temporary structure on the campus to hold the Radiation Laboratory – dwells a group of hardcore nerd “hackers” who call themselves the Tech Model Railroad Club. They use the 2nd floor of the building to run an enormous model train set-up, forever tinkering with wires and switches. For an offshoot of this  group, known jokingly as the Hingham Institute (referencing a dilapidated apartment building located on Hingham St. in Cambridge, Mass that some of the members live in), activities include obsessively discussing the space-opera novels of E.E. “Doc” Smith, considered the grandfather of the literary SF genre. They dream up wild fantasies of special-effects-ridden movie sequences based around the writer’s Skylark and Lensman novels, containing descriptions of vast interstellar spaceship battles.

A photo of Steve Russell

Steve Russell, lead creator of Spacewar!, undated photo

Gravitating from the wires and switches of their train set to the wires and switches of early mainframe computers, eventually word comes down to these hackers that MIT’s aging transistorized TX-0 computer, located in Building 26 on the second floor Research Laboratory of Electronics (RLE), is getting a slick new companion: the relatively svelte Digital Equipment Corporation PDP-1. Not only is this new “mini”-computer sexily compact, it also revolutionizes the computer industry by allowing a single programmer in front of its control panel to have complete access to the processor, as opposed to the prevalent idea of time-sharing computer power. Previous CRT display demonstration programs (like Tennis For Two at Brookhaven Labs, they are developed for public open house purposes) for the TX-0 had consisted of the aptly-named Bouncing Ball, Mouse in the Maze (users built mazes for electronic mice to run around in), and the venerable Tic-Tac-Toe. A TMRC brainstorming session is called to create a truly taxing demo program for the enhanced capabilities for the PDP-1. All present are around 25 years old: Wayne Witanen and J. Martin Graetz, along with a 23 year-old math major from Dartmouth named Steve Russell, an AI specialist known as ‘Slug’ by his buddies due to his tendency to procrastinate. The group of hackers who would develop this amazing demonstration of computer gaming are products of both the department at MIT handling the fabled TX-O mainframe computer, one the first of such beasts to eschew vacuum tubes and be fully transistorized, and the equally odd-ball crew at the Artificial Intelligence Lab. During bull-sessions about the demo program at the Hingham Institute, they develop the Theory of Computer Toys: 1) It should demonstrate the computer’s resources and tax those resources to the utmost. 2) It should be interesting, therefore different every time it is run. 3) It should actively involve the user, as in it should be a game. Recalling E.E. Smith’s epic space battles, the idea forms to pit two spaceships with limited fuel supplies against each other in a missile duel. The program becomes Spacewar!, with Russell as main programmer. Little does he know that his program would eventually result in the loss of computer productivity estimated into the millions of dollars.

Waging Spacewar!

Two spaceships, called the wedge and the needle according to their shapes, are rendered in rough outline graphics. They are controlled by switches on the front panel of the PDP-1, with a left-right toggle switch to rotate the ships clockwise and counterclockwise, and another toggle switch moving forward and back; back to apply thrust to your ship, and forward to put yourself in the hands of fate and activate hyperspace. Other programmers throw aid to Russell, including a sine-cosine routine from Alan Kotok, and a very realistic star field backdrop program called Expensive Planetarium by Peter Samson. Dan Edwards develops the accurate gravity effects in the game, centered around a bright sun at the center of the screen, the gravity well of which would draw careless pilots in to their doom. Graetz develops the Hyperspace feature, used to get a player out of scrapes by disappearing and then randomly reappearing on the screen. In order to deter spacefarers from relying too much on this crutch, multiple uses of hyperspace steadily increase the odds that your ship will explode when coming out of it. By spring of 1962, the game is completed, weighing in at a grand total of 9K.


Fed into the PDP-1 via paper tape input and viewed on the attached CRT screen, Spacewar causes a sensation with its debut at MIT’s annual Science Open House that May, and a scoring system must be introduced to limit people’s time at the control switches used to play. History is also made by Kotok and fellow Spacewar addict Bob Sanders, who are sick of the elbow fatigue caused by holding the toggle switches on the PDP-1 to control the action. Raiding the spare-parts bin of the TMRC, they put together two wooden control boxes, wired directly into the computer. With dedicated switches and buttons to control the game in hand, these could be considered the first gaming joysticks. The fervor over the game among nerds at MIT causes the school to take the step of banning Spacewar, outside of lunch breaks and after work hours. Sick of cleaning up the beer cans and other trash after all-night marathon sessions at the computer by students from all over the campus destroying each other’s spaceships, MIT administration eventually orders all copies of Spacewar! destroyed.

Of course, a couple of copies of Spacewar! survive the great purge and paper-tape backups quickly spread to other educational facilities in the U.S…. who then equally seek to limit or ban Spacewar! from their computer centres. Even DEC uses the program to demonstrate the capabilities of the PDP-1 to new clients and includes it free with every installed system.

Free Range Warfare

Once again, just like Willie Higinbotham, Russell doesn’t seek to copyright or patent his work. Not only would seeking royalties contradict the hacker ethos revered by these early computer geniuses, but also pertinent is the fact that the system Spacewar is running on is hardly a consumer product: it’s the size of three refrigerators and costs $120,000. On top of all that, the creators weren’t even sure if a program could be copyrighted. The open source nature of Spacewar! encourages modification: such as the work of Ken Harrenstein, Charles Frankston and Gary Palter from MIT, who, among other changes they make in 1974, convert the wedge and needle ships into shapes closely resembling the starship Enterprise from Star Trek, and call their version Vector of Mysteries. What Paramount and NBC might think of their creation is unknown…. although this design motif will be carried forward by Larry Rosenthal when he does the same thing for one of his ships in his later Spacewar! arcade copy called, blatantly, Space Wars. Speaking of the commercial front, due to its ubiquitous nature and public domain status, the original Spacewar! will end up as the foundation of the entire video game industry and one of the most copied concepts in the medium. It inspires arcade translations such as the first commercial arcade video games, Galaxy Game and Computer Space, as well as the aforementioned vector graphics game Space Wars by Rosenthal and Cinematronics, as well as Atari’s answer to that game, Orbit, and even on to the company’s smash hit Asteroids. The Spacewars concept also materializes early on in home video games for systems like the Channel F and the Atari VCS. logo_stop

Sources (Click to view; inert links kept for historical purposes)

The Origin of Spacewar!”, by J. M. Graetz, reprint of 1981 Creative Computing magazine article –

Museum of Computing Magazine, “The Mouse That Roared: PDP-1 Celebration Event!”, Spring/Summer 2006 Issue, pg. 3
Video games
PDP-1 Plays at Spacewar” – 1962 Decuscope newsletter article by D.J. Edwards and J.M. Graetz

Image of Astounding cover, and E.E. Smith from Starlog, “The Worlds of E.E. ‘Doc’ Smith”, by David Kyle, pgs. 45-46, Feb 1989
Colour image of the PDP-1 computer and peripherals, and Steve Russell, taken by William Hunter at the Computer History Museum, Mountain View CA
Kent, Stephen L. “The Great Videogame Swindle?” Next Generation, Nov. 1996, pp. 64–229. Tired of having sore elbows, Alan Kotok and Bob Sanders scrounged parts from the Tech Model Railroad Club and assembled remote controllers that could be wired into the computer. These remotes were easier to use than the PDP-1’s native controls, they had dedicated switches for every Spacewar function, including hyperspace buttons. This was the forerunner to the joystick.
Spacewar” – 1972 Rolling Stone article by Stewart  Brand
Eimbinder, Jerry, and The History of How We Play. “TV Game Background.” Gamestronics Proceedings, Jan. 1977, pp. 159–165. Internet Archive, buffs estimate that Russell’s ingenuity cost companies possessing computers several million dollars during the following three or four years;
Image of the Spacewar! control box from reprint of same article in Creative Computing Video & Arcade Games, pg.84, Vol. 1 No. 1, Spring 1983
Jordan, Gerald B. “Already, a Museum of the Computer Age.” The Philadelphia Inquirer 15 Nov. 1984: 1-C-1-C. Web. 27 July 2021. The invention [Spacewar!] was not copyrighted, he [Martin Graetz] said, because the idea for it had been widely distributed among engineering students and there seemed to be little mass appeal for it since the computer to run it at the time cost $125,000. Besides, Graetz added “we weren’t sure a program was something that could be copyrighted.”
Sauter, Eric. “Fighting a Spacewar in the No-Name Lab.” The Boston Globe 21 Apr. 1974: 6. Web. 26 July 2021. Image of Ken Harrenstein and Gary Palter in front of Spacewar! Photo by Ed Fitzgerald. Other info: Welcome to Ken Harrenstein’s ‘Star-Trek’ game, folks. Par of the credit for this computer marvel goes to a couple of Ken’s accomplices, Charles Frankston and Gary Palter. ;There is also a change that you’ll blow up coming out of hyperspace anyway. The first time you use it as an evasive action, the changes are one in eight that you’ll explode. The second time you use it, the changes are one in seven and so on. ;”in one of the older computer labs,” Mike Beeler said, “students could come in and sign up for computer time….They would wreck the place playing Spacewar. In the morning there’d be beer cans and litter all over the place. So after one particularly bad evening they finally decided to end it. They destroyed all the copies of the Spacewar program.” He adds: “Except one or two, of course.” ;I have a copy of the print-out for Ken’s modified Spacewar game. It is called, not surprisingly, the Vector of Mysteries.;This computer craziness began at the MIT Electrical Engineering Department back in 1961-62 with a 23-year-old Dartmouth math major named Steve Russell.
Electronic Games, “Players Guide To Electronic Science Fiction Games”, pgs. 35 – 45, Mar. 1982
Hays Daily News, “Forty years of change since ‘Spacewar'”, by John D. Montgomery, pg. A4, Mar. 31, 2002
Phoenix: The Fall and Rise of Videogames, by Leonard Herman
The Museum of Science, Boston –
Eimbinder, Jerry, and The History of How We Play. “TV Game Background.” Gamestronics Proceedings, Jan. 1977, pp. 159–165. Internet Archive, Image of Galaxy Game installed at Tressider Union Coffeehouse, 1977, photo by Liane Enkelis
Digital Computing Timeline –
Electronic Nation, by Steven L. Kent –’s History of Video Games –
Digital Equipment Corporation. PDP-1 Manual. Maynard, MA: Digital Equipment Corporation, 1962. Print. Abbreviated Instruction List

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