tennis for two


Tennis Anyone?

So now we turn to the most discussed of all the 1950s computer games: Tennis for Two, designed by Willy Higinbotham and largely built by Robert Dvorak at the Brookhaven National Laboratory (BNL) in 1958.  Unlike the games discussed previouslyTennis for Two was built specifically to entertain the public rather than just to demonstrate the power of a computer or train a group of students, giving it some claim as the first true computer “game” from a philosophical standpoint.  That is certainly the contention of BNL itself, which dismisses NIMROD and OXO as programming demonstrations rather than entertainment.  Ultimately, this debate matters little, as Tennis For Two only existed briefly and did not influence later developments in the industry.

While Tennis for Two did not inspire later designers, however, it did gain a new notoriety in the 1970s when lawyers for arcade companies defending against a patent lawsuit brought by Magnavox discovered the existence of the game and unsuccessfully attempted to portray it as an example of prior art that invalidated Ralph Baer’s television gaming patents.  Higinbotham was called to testify on multiple occasions during various patent suits that continued into the 1980s, which is one reason the game is far better documented than most of its contemporaries.  The game also received public recognition after Creative Computing ran a feature devoted to it in October 1982 because the magazine’s editor, David Ahl, had actually played the game at Brookhaven back in 1958.  As a result of this article, Tennis for Two was considered the first computer game until more in-depth research in the late 2000s uncovered some of the earlier games listed in the previous post, and the early monographs such as PhoenixHigh Score!, and The Ultimate History of Video Games accord the game pioneering status.  Even though newer works like Replay and All Your Base Are Belong to Us acknowledge earlier programs, however, they continue to give Tennis for Two pride of place in the early history of video games due to it arguably being the first pure entertainment product created on a computer.


William A. Higinbotham

Before diving into the game itself, we should examine the man who created it.  According to an unpublished account now hosted at the BNL site that he wrote in the early 1980s supplemented by a deposition he gave in 1985, William A. Higinbotham graduated from Williams College in 1932 with a bachelor’s degree in physics and spent eight years working on a Ph.D at Cornell that he ultimately abandoned due to a lack of money.  Higinbotham first worked with an oscilloscope during a senior honor’s project at Williams and spent his last six years at Cornell working as a technician in the physics department, which gave him the opportunity to learn a great deal about electronics.  As a result, he was invited to MIT in December 1940 to work on radar at the university’s Radiation Laboratory, where he concentrated on CRT radar displays.   In December 1943, Higinbotham transferred to Los Alamos to work on the Manhattan Project, where he was quickly promoted to lead the electronics division and, according to Replay, worked on timing circuits.  He left Los Alamos for Washington, DC, in December 1945, where he spent two years doing education and PR work for the American Federation of Scientists, a group that worked to stem nuclear proliferation.  In 1947, he came to BNL, where he became the head of instrumentation in 1951 or 1952.

The above provides a solid overview of Higinbotham the scientist, but Harold Goldberg in All Your Base Are Belong to Us also gives us a portrait of Higinbotham’s less serious side.  According to Goldberg, who drew his information from a profile in Parade, Willy was a natural entertainer who called square dances, played the accordion, and led a Dixieland band named the Isotope Stompers.  He also exhibited a penchant for making technology fun, once attaching a sulky and two wagons to the family lawnmower so he could drive his kids around the yard.  Seeing this side of the eminent physicist, its no surprise that he would find a way to make a computer entertaining as well.


The original Tennis for Two display

Higinbotham created Tennis for Two as a public relations vehicle.  Every year, BNL held three visitor’s days in the fall — one each for high school students, college students, and the general public — in which the scientists gave tours of the facilities and built exhibits related to the lab’s work in the staff gymnasium.  Most accounts of the exhibits emphasize that they consisted of unengaging static displays, but in his 1976 deposition for the first Magnavox patent lawsuit, Higinbotham states that the staff always tried to include something with “action,” though he does not specify whether this included games. Therefore, Higinbotham may not have been the first person to liven up the event through audience participation, but he was still definitely the first person that decided to entertain the public with a computer game.

As the BNL website and his notes indicate, Higinbotham was inspired to create Tennis for Two after reading through the instruction manual for the lab’s Donner Model 30, a vacuum tube analog computer.  The manual described how the system could be hooked up to an oscilloscope to display curves to model a missile trajectory or a bouncing ball complete with an accurate simulation of gravity and wind resistance.  The bouncing ball reminded Higinbotham of tennis, so he sketched out a system to interface an oscilloscope with the computer and then gave the diagram to technician Robert Dvorak to implement.  Laying out the initial design only took Higinbotham a couple of hours, after which he spent a couple of days putting together a final spec based on the components available in the lab.  Dvorak then built the system over three weeks and spent a day or two debugging it with Higinbotham.  The game was largely driven by the vacuum tubes and relays that had defined electronics for decades, but in order to render graphics on the oscilloscope, which required rapidly switching between several different elements, Higinbotham and Dvorak incorporated transistors, which were just beginning to transform the electronics industry.

Tennis for Two‘s graphics consisted of a side-view image of a tennis court — rendered as a long horizontal line to represent the court itself and a small vertical line to represent the net — and a ball with a trajectory arc displayed on the oscilloscope.  Each player used a controller consisting of a knob and a button.  To start a volley, one player would use the knob to select an angle to hit the ball and then press the button.  At that point, the ball could either hit the net, hit the other side of the court, or sail out of bounds.  Once the ball made it over the net, the other player could either hit the ball on the fly or the bounce by selecting his own angle and pressing the button to return it.  Originally, the velocity of the ball could be chosen by the player as well, but Higinbotham decided that three controls would make the game too complicated and therefore left the velocity fixed.


A modern recreation of the Tennis for Two controller

According to Higinbotham, Tennis for Two was a great success, with long lines of eager players quickly forming to play the game.  Based on this positive reception, Higinbotham brought the game back in 1959 on a larger monitor and with more sophisticated gravity modelling that allowed the player to simulate the low gravity of the Moon or the high gravity environment of Jupiter.  After the second round of visitor days, the game was dismantled so its components could be put to other uses.  Higinbotham never patented the device because he felt at the time that he was just adapting the bouncing ball program already discussed in the manual and had created no real breakthrough.  While he appears to have been proud of creating the game, he stated in his notes that he considered it a “minor achievement” at best and wanted to be remembered as a scientist who fought the spread of nuclear weapons rather than as an inventor of a computer game.