Jamma is the arcade standard pinout adopted around 1987 and used on the vast majority of game boards made since 1987. This category includes all of our Jamma boards, most of the ones we sell are tested and working, sometimes we do list broken boards that we don't have the expertise to repair.
Note that some Jamma boards use what we describe as "Jamma+" wiring. Jamma+ wiring is a catch-all description to include additional wiring needed to play the game, things like 3rd and 4th player control connections (for games like NBA Jam and TMNT) and extra buttons (think Street Fighter, Mortal Kombat) generally fall into this category.
Working Atari Badlands arcade circuit board
Capcom Bionic Commando boardset in working cond...
--Jeff Spicolo, Fast Times At Ridgemonnt High