It was while working at DuMont that Thomas T. Goldsmith Jr and Estle Ray Mann created their game, which was directly influenced by Second World War radar displays. The two scientists combined a cathode ray tube with an oscilloscope to allow a player to simulate launching an explosive shell at enemy targets in what they called The Cathode Ray Tube Amusement Device.
The patent stated that targets needed to be physically positioned on the screen of the device using transparent overlays. The player then used the controls of the oscilloscope to position a spot of light created by the CRT, much like the controls on an Etch A Sketch toy, in order to hit the target. When a switch was flicked the spot would move in a parabolic arc, mimicking the flight of a shell, at the end of which the light would become unfocused in imitation of an explosion. If the spread of the beam hit the target, the player scored a hit. Additional controls allowed the player to change the angle and trajectory of the light beam, and change the time delay before detonation.
Despite securing a patent for the device, the game never went into commercial production. The parts were too expensive and DuMont Laboratories were more interested in advancing television technology. Consequently The Cathode Ray Tube Amusement Device’s place in video game history is negligible, and it is likely that later developers created their own games without any knowledge of the work done by Goldsmith and Mann.