An old group trying to set standards for board pinouts (at arcade machines). This was designed to make board changes easy, just take out the old game and plug in the new. Unfortunately games have evolved, and the Jamma standard is no longer up to the job as it can`t handle more than 4 buttons or two players. Also replacing a board from a different manufacturer meant readjusting the picture on the monitor as it would not be centred in the same position.