What is Game control adapter?

What is Game control adapter?
More commonly known as a game port or joystick port, the game control adapter is a 15-pin connector port first found on IBM computers in 1981. The game port is handled by the SIO and allows users to connect such devices as joysticks, game pads, steering wheels and various other devices that allow additional functionality to the computer.

There were some motherboards that included a joystick port built in and for those that did not an internal ISA or PCI card, with a joystick port on it could be installed in the computer. Today, this port has been largely replaced by game devices that connect using USB and the 15-pin connector is no longer used.