The following description is based on research and documentation via the game's registered patent (#2455992). No working model of the game exists today.
Based on the World War II radar displays, players use knobs to adjust the trajectory of light beams (missiles) in an attempt to hit targets printed on clear screen overlays.
In the 1940s, while specializing in the developments of cathode ray tube readings of electronic signal outputs (used in the development of televisions and monitors) physicists Thomas T. Goldsmith Jr. and Estle Ray Mann came up with the idea of creating a simple electronic game inspired by World War II radar displays. By connecting a cathode ray tube to an oscilloscope and devising knobs that controlled the angle and trajectory of the light traces displayed on the oscilloscope, they were able to invent a missile game that, when using screen overlays, created the effect of firing missiles at various targets.
By 1947, Goldsmith and Mann submitted a patent for the device, calling it the Cathode-Ray Tube Amusement Device, and were awarded the patent the following year, making it the first ever patent for an electronic game.
Unfortunately, due to the equipment costs and various circumstances, the Cathode-Ray Tube Amusement Device was never released to the marketplace. Only handmade prototypes were ever created.
- Cathode-Ray Tube: Creates and adjusts the electronic signal.
- Oscilloscope: Displays the electronic signal via rays of light on a monitor.
- Screen Overlays: The graphics of the game, printed on a clear overlay that attach to the oscilloscope screen. Screen overlays were later used for the first home video game console, the Magnavox Odyssey.
- Controller knobs: Adjusts the angle and movement of the light beams on the Oscilloscope.
A Cathode-Ray Tube is a device that can register and control the quality of an electronic signal. Once connected to an Oscilloscope, the electronic signal is visually represented on the Oscilloscope's monitor as a beam of light. The electronic signal quality is measured by how the beam of light moves and curves on the display.
The control knobs adjust the strength of the electronic signal output by the Cathode-Ray Tube. By adjusting the signal strength the beams of light that output onto the Oscilloscope appear to move and curve, allowing the player to control the trajectory on which the ray of light moves.
Once screen overlays with target graphics printed onto them are placed on the Oscilloscope screen, the player tries to adjust the ray to deflect onto the target. One of the amazing tricks that Goldsmith and Mann came up with was an effect to make the appearance of an explosion when a target is hit. This was done by adjusting a sliding contactor (a relay switch that controls the flow of energy through a circuit) to overpower a resistor in the Cathode-ray Tube with such a powerful signal that it makes the display go out of focus and appear as a blurred round spot, hence creating the appearance of an explosion.
The First Video Game?:
Although the Cathode-Ray Tube Amusement Device is indeed the first patented electronic game and is displayed on a monitor, many do not consider it an actual video game. The device is purely mechanical and does not use any programming or computer generated graphics, and no computer or memory device is used at all in the creation or execution of the game.
Five years later, Alexander Sandy Douglas developed artificial intelligence (AI) for a computer game called Noughts and Crosses, and six years after that Willy Higinbotham developed Tennis for Two, the first publically displayed computer game. Both of these games use an oscilloscope display and are in the mix to take credit as the first video game, but neither would exist without the discoveries and technology created by Thomas T. Goldsmith Jr. and Estle Ray Mann.
- Aside from the patent and some prototype schematics, there is no known working model of the Cathode-Ray Tube Amusement Device in existence.
- Co-Inventor Thomas T. Goldsmith went on to become one of the pioneers of television, starting out as the Vice-President; Director of Research for DuMont, the world's first commercial television network.