The Atari joystick port is a computer port used to connect various gaming controllers to game console and home computer systems in the 1970s to the 1990s. It was originally introduced on the Atari 2600 in 1977 and then used on the Atari 400 and 800 in 1979. It went cross-platform with the VIC-20 in 1981, and was then used on many following machines from both companies, as well as a growing list of 3rd party machines like the MSX platform and various Sega consoles. The port, based on the inexpensive 9-pin D-connector, became a de facto standard through the 1980s and into the 1990s, supported by a wide variety of joysticks and other devices, most commonly paddle controllers, light pens and computer mice. The standard was so engrained that it led to devices like the Kempston Interface that allowed Atari joysticks to be used on the ZX Spectrum. The port was also used for all sorts of non-gaming roles, including the AtariLab interface, modems, numeric keypads, and even a video expansion card. By the mid-1990s, the last home computer and game console models using Atari ports – often for both joystick and mouse – were discontinued. IBM PC-compatible computers, which did not have Atari joystick ports, became dominant in the home computer market, and console manufacturers such as Sega switched to other types of ports. The Atari Video Computer System (later the 2600) developed out of an effort to address problems Atari found when releasing their first home video game console, Pong. Although successful, Pong was an expensive system to design, and was dedicated solely to one game. It would be much more practical to have a machine that could run multiple games. The list of games it would need to support included Pong variations, and Tank. It was the desire to run these two games that led to the need for some sort of flexible input system; Pong used analog paddle controllers, while Tank used dual digital (on/off) joysticks. Arcade games of the era generally used paddles, joysticks or a unique sort of steering wheel controller that was spun, entirely unlike a real car.