When did the Game Boy come out?
Game Boy
The right-side of the device offers a port which allows a user to connect to another Game Boy system via a link cable, provided both users are playing the same game.[22] The port can also be used to connect a Game Boy Printer. The link cable was originally designed for players to play head-to-head two-player games such as in Tetris. However, game developer Satoshi Tajiri would later use the link cable technology as a method of communication and networking in the popular Pokémon video game series.[23]