Tennis for Two

Tennis for Two is an electronic tennis game designed in 1958 by American nuclear physicist William Higinbotham? for the annual visitors’ day at Brookhaven National Laboratory? in Upton, New York, and is frequently credited as one of the earliest video games ever built, though its status as the first has been disputed since research uncovered several electronic games that preceded it.³²³ Games such as the cathode-ray tube amusement device patented by Thomas T. Goldsmith Jr. and Estle Ray Mann in 1947, the Nimrod? computer built in 1951 to play Nim, and OXO, a noughts-and-crosses game written for the EDSAC? computer in 1952, all antedate it.²¹⁷

Historians nonetheless continue to accord Tennis for Two a prominent place in early video game history as arguably the first entertainment product created on a computer and the first to feature moving graphics under player control.³² Displayed on the five-inch screen of an oscilloscope and driven by an analog computer, it presented a side view of a tennis court on which two players volleyed a bouncing dot across a net using handheld controllers.⁸¹⁵ It was first shown to the public on October 18, 1958.⁹¹¹

Higinbotham, then head of Brookhaven’s Instrumentation Division, created the game as a public-relations exhibit for the laboratory’s fall open days, at which thousands of visitors toured the government research facility.¹⁵¹⁷ He had found the annual displays static and dull — mostly photographs, posters, and inert machinery — and wanted something interactive, later writing that “it might liven up the place to have a game that people could play, and which would convey the message that our scientific endeavors have relevance for society”.¹¹¹⁷ The idea came from the instruction manual for the lab’s Donner Model 30, a vacuum-tube analog computer, which described how the machine could be hooked to an oscilloscope to plot the trajectory of a bouncing ball complete with gravity and wind resistance; the bouncing ball reminded Higinbotham of tennis.¹¹⁷

Higinbotham sketched out the initial design in a couple of hours and spent a few days preparing a final specification based on components available in the lab.¹¹⁵ The device was largely built by technician Robert V. Dvorak?, who assembled it over roughly three weeks before he and Higinbotham spent a day or two debugging it.¹¹⁰ Higinbotham made the drawings and Dvorak built a patchboard from them, correcting circuits that did not work until the game ran in time for the tour.¹⁰ Official blueprints were drawn up by design engineer Alexander Elia based on Higinbotham’s originals.¹⁰ The circuitry consisted mostly of resistors, capacitors, and relays, but incorporated recently commercialized germanium transistors as fast switches for the rapid time-sharing needed to draw the court, net, and ball on screen while the ball was in play.¹⁵¹⁷

The display showed a side view of a tennis court rendered as a long horizontal line for the ground and a short vertical line for the net, with the ball appearing as a bright moving dot that left trails as it bounced.¹⁸ Each player used a controller with a knob and a button: the knob set the angle of the shot, and the button hit the ball.⁹¹⁵ Gravity, wind speed, and bounce were all simulated — a ball striking the net rebounded lower than one bouncing off the ground — and when the ball went out of bounds a reset button returned it to the start; players kept score themselves.⁶¹⁵ Four of the computer’s operational amplifiers generated the ball’s motion while six others sensed when it struck the ground or net and switched control to the appropriate side.¹⁷

The exhibit was an immediate success, with hundreds of visitors lining up for a turn while scientists at neighboring booths looked on at their own deserted displays.⁹¹⁵ Higinbotham later attributed the crowds less to the game’s brilliance than to the dullness of the other exhibits, remarking that “the long line of people I thought was not because this was so great but because all the rest of the things were so dull”.¹⁵ A revised version appeared at the 1959 visitors’ day featuring a larger screen and the ability to vary gravity, allowing players to simulate tennis on the Moon or Jupiter.²¹⁵ After 1959 the game was retired and its oscilloscope and computer reassigned to other tasks, and the original was dismantled about a year after its debut.¹⁵⁸

Tennis For Two - The second ever computer gameDan C

Higinbotham, who had graduated from Williams College? in 1932 and studied physics at Cornell University?, had worked on radar displays at MIT’s Radiation Laboratory and on timing circuits for the atomic bomb at Los Alamos? during the Manhattan Project? before joining Brookhaven in the late 1940s.¹⁵³ He never patented Tennis for Two — he already held some twenty patents but did not consider the game particularly innovative, and as a government employee any patent would have belonged to the United States.¹⁵¹⁷ His principal career interest was nuclear nonproliferation; he was a founder and first chairman of the Federation of American Scientists?, and by his death in November 1994 was better known for the game than for his arms-control work.⁹¹⁵

Tennis for Two was largely forgotten for two decades and, according to the video game historian who runs the site They Create Worlds, existed too briefly to influence later developments in the industry.¹ It gained new notoriety in the 1970s when lawyers defending arcade companies against a patent suit brought by Magnavox? discovered the game and unsuccessfully attempted to portray it as prior art invalidating Ralph Baer?’s television-gaming patents.¹¹⁵ Higinbotham was called to testify in patent litigation that continued into the 1980s, which is one reason the game is far better documented than most of its contemporaries.¹ It entered wider public awareness after Creative Computing magazine, whose editor David Ahl had played it at Brookhaven as a high-school scholarship winner in 1958, ran a feature on it in October 1982.¹¹⁰

That article led to the game being considered the first video game until deeper research in the late 2000s uncovered earlier programs.¹ Its status has been disputed on the grounds that several electronic games preceded it: the cathode-ray tube amusement device patented by Thomas T. Goldsmith Jr. and Estle Ray Mann in 1947, which required a screen overlay; the Nimrod? computer built in 1951 to play Nim; and OXO, a noughts-and-crosses game written for the EDSAC? computer in 1952.²¹⁴ Historians nonetheless continue to give Tennis for Two pride of place in early video game history as arguably the first entertainment product created on a computer and the first to feature moving graphics under player control.¹²

The original was never preserved, but in 1997 physicist Peter Takacs and colleagues at Brookhaven recreated it for the laboratory’s 50th birthday using the original circuit schematics, substituting modern solid-state operational amplifiers because they could not locate an original vacuum-tube Donner Model 30.¹²¹¹ The rebuild took about three months and suffered from voltage spikes that blew out the sensitive solid-state chips, requiring protective circuits.¹¹¹² Takacs’s team later acquired a Donner Model 3400 analog computer and worked to restore the game to its original 1958 configuration.⁸¹² A working recreation was displayed again for the game’s 50th anniversary in 2008.¹¹¹⁶ The William A. Higinbotham Game Studies Collection? at Stony Brook University? preserves records and artifacts documenting the game.¹⁹