JAMMA is an acronym, standing for Japanese Amusement Machine Manufacturers' Association. This term represents three different things: a trade association, a trade show in Japan and a wiring standard for arcade machines.

The JAMMA wiring standard was introduced in the mid-1980s. 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. Many games exist which almost conform to the standard but extend it in some way, for example by adding support for extra buttons. These games are sometimes referred to as JAMMA+.

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 and update of the artwork.

The JAMMA standard includes signals for two eight-direction joysticks, two player start buttons and six control buttons (three per player), with monaural sound.

A popular project for some is to connect a JAMMA cabinet to a PC instead of the dedicated arcade PCB. Using a JAMMA interface wired to the keyboard, video and mouse ports of the PC, it is possible to run an arcade emulator such as MAME (Multi Arcade Machine Emulator). This allows the JAMMA cabinet to become whichever arcade game is chosen on power up of the PC.

External links

• JAMMA Official Site
• Japanese Official Site
• PC -> JAMMA interface