It was the traditional connector for joystick input, and occasionally MIDI devices, until made obsolete by USB in the late 1990s.

[2][3][4] The Apple II,[5] BBC Micro,[6] TRS-80 Color Computer,[7] and other popular 8-bit machines all used different, incompatible, joysticks and ports.

The most common device available was the Kraft joystick, originally developed for the Apple II but easily adapted to the IBM with the addition of another button on the back of the case.

[13] The game port became somewhat more common in the mid-1980s, as improving electronic density began to produce expansion cards with ever-increasing functionality.

[14] The era of combo expansion cards largely came to an end by the late 1980s, as many of the separate functions normally provided on plug-in boards became common features of the motherboard itself.

[15] By the end of the year the Sound Blaster was the best selling expansion card on the PC, and the game port was receiving widespread software support.

In 2001 the Sound Blaster Audigy moved the game port to a second expansion slot, which connected to a header on the card.

[17][circular reference] The introduction of the first USB standard in 1996 was aimed squarely at the sort of roles provided by the game port, but initially had little market impact.

For instance, the 1997 Microsoft Precision Pro joystick was re-introduced in a version that used a game port connector, but also included a USB adapter in the box.

[22] The analog channels are read by sending voltage into the line, through a potentiometer in the controller, in this case 100,000 ohm, and then into a capacitor.

In the Atari port, which had similar analog channels, there is a convenient timer available in the form of the video clock circuitry.

[24] Initially there was no standardized software for running the joysticks; applications would poll the known ports associated with the sticks as part of their game loop.