T42 – Tennis for Two

T42 – Tennis for Two

With the goal of documenting a milestone of the electronic games history and once again out of sheer joy in experimenting and spirit of research T42 (pronounced “Tea for two”) has been created, the only existing 100% analog and fully playable reconstruction of Tennis for Two by William Higinbotham from 1958. This replica, completed May 2011 as part of the project MEGA – Museum of Electronic Games & Art, is closest to the original. Not only that it resurrects long forgotten technology, it also preserves the its charismatic relevance for both computer and video game history.


Tennis for Two is a multi-player game. In this tennis simulation two players can move a light dot from one side to the other while changing the angle of the ball and its flight path. The red button lets you hit the ball, when it passes the net, your opponent is allowed to hit and return.

Graphics and Sounds

Video screen is a 5″ analog oscilloscope. Ball, net and court are displayed in a side-view. The movement of the ball is a graph within a two-dimensional coordinate system, where the X-axis represents time and Y-axis represents voltage. Change of voltage is displayed through a trail of light.

Five relay sections produce the charismatic sounds of T42, prettifying the events serve, return, net ball and player change.


  • Service: Start of the game. The ball must be played to the opponent’s side.
  • Return: The opponent hits and returns the ball.
  • Smash: Ball played at a high speed and low angle.
  • Volley: Ball is returned before touching the ground.
  • Net: The ball is caught by the net. The opponent scores.
  • Winner: The opponent does not return the ball. Player scores.
  • Ace: Service cannot be returned by the opponent. Player scores.

Game logic and Gameplay

Original diagram of Tennis for Two game logic (1958)

Serve A player starts the game. By turning the rotary knob the player changes charge of two capacitors (one for X-axis and one for Y-axis). Service is realized by switching several relais and starts discharging the capacitors as a simulation of gravity and air resistance. Serving player gets interlocked and player change happens.

Net If the ball does not pass the net at minimum height, the X-axis of the ball movement gets inverted and the ball bounces off the net and back towards the player. The Y-axis is not affected. After the ball has reached the end of court the game restarts.

Restart Relays cause the change of play direction. The ball is positioned on the winner’s side until he hits.

Bounce When the ball touches the ground a relay changes direction of the Y-axis and the ball bounces off and up. It loses energy and thus height (Y-axis) on each bounce.

End of court If the opponent does not play the ball, the game stops and restarts. The ball gets repositioned on the player’s side.

Net pass If the ball passes the net, relays release the interlock of the opponent and allow him to play.

Return please see “Serve”.

Long-term Preservation and Access

Before the first T42 kits are available from MEGA, you can enjoy our (unified) app for iPhone, iPad and iPod – in store now!

Historical Context

There are some pioneering inventions before today’s computer and video games. On 18 October 1958 hundreds of visitors waited in line to play the first electronic action game, a two-dimensional tennis game played on the small screen of a cathode ray tube oscilloscope. It displayed the side view of a tennis court with a net in the middle and a bright moving point – the ball. It also had controllers to manipulate an invisible tennis racket: A rotary knob to change the angle and a trigger to “hit” the ball.

Only 13 years after the 2nd World War mankind was concerned about a further escalation and experiencing cold war. Pushing of the red button was associated with a nuclear third world war. At exactly this time just the physicist, who had been involved in the development of the atomic bomb at an American nuclear research center, started a project to give the dreaded red button a whole new meaning.

Tennis for Two is the first electronic tennis game on an oscilloscope. Specifically designed for entertainment and invention, and most of all the forefather of today’s computer and video games.

On 18 October 1958 William Higinbotham showed the ancestor of today’s video games to the astonished public.

Tennis for Two is one important milestone in the history of the billion dollar computer and video game industry:

  • It’s the first sports game.
  • It’s the first game completely displaying the game graphics in real time.
  • It’s the first game having two controllers for two players and thus fulfilling the long-term requirements of interactivity.
  • It is the first computer game that was specifically developed to entertain the public.

For further detailed information, please visit the website of Brookhaven National Laboratory.

Background information

For the sake of completeness the first patent of a technical idea in this field and the earliest known computer games have to be named.

On 14th December 1948 the first U.S. patent was requested by Thomas Goldsmith, Cedar Grove and Estler Man Ray, the Cathode-Ray Tube Amusement Device. Inspired by radar displays from World War II, a missile game with video screen overlays was developed, but never finished.

In 1951 the first graphical computer game OXO (Noughts and Crosses) was released. This Tic-tac-toe based puzzle game was run on an Electronic Delay Storage Automatic Calculator (EDSAC) Computer by Professor Alexander “Sandy” Shafto Douglas.

Spacewar! by Steve Russel, Martin Graetz and Wayne Witaenem was released in 1962 on a PDP-1 (Programmed Data Processor-1), a Digital Equipment Corporation (DEC) product. The Computer History Museum owns the last three existent PDP-1 computers. One computer with display was completely restored and is running Spacewar! as well as other programs since 2006. You can find detailed information at the PDP-1 Restoration Project website of the Computer History Museum in Mountain View, California.

← Back to research