Jamma - Connector Standards

Connector Standards

The JAMMA wiring standard was introduced in 1985. Arcade cabinets wired to the JAMMA standard can be made to play all games built to this standard, simply by installing the circuit boards for the new game. By the 1990s, most new arcade games were JAMMA standard. As the majority of arcade games were designed in Japan at this time, JAMMA became the de facto world standard.

Before the JAMMA standard, most arcade PCBs, wiring harnesses, and power supplies were custom-built. When an old game became unprofitable, many arcade operators would rewire the cabinet and update the artwork in order to put different games in the cabinets. Reusing old cabinets made a lot of sense, and it was realized that the cabinets were a different market from the games themselves. The JAMMA standard allowed plug-and-play cabinets to be created (reducing the cost to arcade operators) where an unprofitable game could be replaced with another game by a simple swap of the game PCB, and an update of the artwork.

The JAMMA standard uses a 56-pin edge connector on the board with inputs and outputs common to most video games. These include power inputs (5 volts for the game and 12 volts for sound); inputs for two joysticks, each with three action buttons and one start button; analog RGB video output with negative composite sync; single-speaker sound output; and inputs for coin, service, test, and tilt (the former to accept game credits and the latter to maintain the board).

Later games (e.g.: Street Fighter II, X-Men) use arcade boards that incorporate extra connectors or utilize unused JAMMA pins to implement extra buttons, different controller types, or support more players. These games are sometimes referred to as JAMMA+.