The cathode ray tube amusement device is the earliest known interactive electronic game. Thomas T. Goldsmith Jr. and Estle Ray Mann constructed the game from analog electronics and a cathode ray tube (CRT) in 1947.[1]
Goldsmith and Mann's patent application describes a game of skill in which a player sits or stands facing a cathode ray tube (CRT) video screen mounted in a cabinet. Goldsmith and Mann designed the game to resemble a World War II radar display, but with airplanes or some other targets painted onto a transparent overlay (since this invention preceded the era of computer graphics).
The player turns a control knob to position the CRT beam on the screen; to the player, the beam appears as a dot, which represents a reticle or scope. The player has a restricted amount of time in which to maneuver the dot so that it overlaps an airplane, and then to fire at the airplane by pressing a button. If the beam falls within the preprogrammed coordinates of a target when the user presses the button, then the CRT beam defocuses, simulating an explosion.
OXO, a version of Tic-Tac-Toe, ran on the EDSAC computer, a CRT amusement device.[2]