Cathode-ray tube amusement device

The cathode-ray tube amusement device is the earliest known interactive electronic game as well as the first game to incorporate an electronic display. The device simulates an artillery shell arcing towards targets on a cathode-ray tube (CRT) screen, which is controlled by the player by adjusting knobs to change the trajectory of a CRT beam spot on the display in order to reach plastic targets overlaid on the screen. Thomas T. Goldsmith Jr. and Estle Ray Mann constructed the game from analog electronics and filed for a patent in 1947, which was issued the following year. The gaming device was never manufactured or marketed to the public, so it had no effect on the future video game industry. Under many definitions, the device is not considered a video game, as while it had an electronic display it did not run on a computing device. Therefore, despite its relevance to the early history of video games, it is not generally considered a candidate for the title of the first video game. The cathode-ray tube amusement device consists of a cathode-ray tube (CRT) connected to basic oscilloscope type circuitry with a set of knobs and switches. The device also incorporates very simple analog circuitry and does not use any digital computer or memory device or execute a program. The CRT projects a spot on the display screen, which traces a curved arc across the screen when a switch is activated by the player. This beam spot represents the trajectory of an artillery shell. The curved path is produced by the CRT, which is not of conventional design, deflecting the beam of electrons as the spot moves across the screen. Overlaid on the screen are transparent plastic targets representing objects such as airplanes. At the end of the spot's trajectory, the beam defocuses, resulting in the spot expanding and blurring. This represents the shell exploding as if detonated by a time fuze. The goal of the game is to have the beam defocus when it is within the bounds of a target.