Handheld electronic game by less bright dots). In 1978 the Milton Bradley Company entered the handheld market with Simon, a simple color-and-sound-matching game. Simon had no dedicated display, but featured four colored, lighted buttons; the original version was large enough to be used as a tabletop game or a handheld; later versions became increasingly smaller. The same year, Parker Brothers also released Merlin, a more sophisticated handheld which could play six different games using an array of 11 buttons with integrated LEDs. Despite their relative simplicity, each of these early games was highly successful. The initial success of Mattel and Parker Brothers' entries
Bertie the Brain the position for their next move from a grid of nine lit buttons on a raised panel. The moves would appear on a grid of nine large squares set vertically on the machine as well as on the buttons, with either an X- or O-shaped light turning on in the corresponding space. The computer would make its move shortly after. A pair of signs to the right of the playfield, alternately lit up with "Electronic Brain" and an X or "Human Brain" and an O, marked which player's turn it was, and would light up along with "Win" when a