Japanese Amusement Machine Manufacturers' Association
From GamerWiki
What is JAMMA?
Way back in the late seventies and early eighties each arcade manufacturer would have their own way of connecting their arcade PCBs (printed circuit boards) to the arcade machine. This situation meant that if an operator wanted to put a new game in his cabinet he'd have to perform some re-wiring for each game. Obviously this wasn't a sensible option, and so the JAMMA standard was introduced by the majority of arcade game companies in 1986.
The majority of PCBs released since 1985 conform to the JAMMA (Japanese Arcade Machine Manufacturers Association) standard, and can be swapped in and out of a JAMMA cabinet in a few seconds. If a PCB isn't JAMMA, it is highly likely that an adaptor can be built to convert it.
Examples of JAMMA boards include Rastan and New Zealand Story. Boards that can be easily converted to the JAMMA standard include Galaga, Phoenix and Bombjack.
Of course, there are some boards that cannot be converted to JAMMA easily. Games like Defender and Pacman require extra circuitry to perform sync, video conversion, or modification to the PCB (Pac-Man needs this for power supply). It's not impossible, but this is definitely NOT recommended for beginners.
Lastly, there are Vector games that run on a different type of monitor to the normal games you're used to. These include Battlezone, Asteroids and Tempest. It is impossible to convert these to JAMMA due to the monitor requirements.
As JAMMA is pretty much the defacto standard nowadays, you can be sure that any decent PCB stockist will have an excellent selection of JAMMA boards for sale. Many collectors (and some dealers) offer a JAMMA adaptor-building service to enable classic pre-JAMMA boards like Galaga and Phoenix to be run in a JAMMA cab.
JAMMA Pinouts
The Jamma pinout uses a 2X28 way 0.156" edge connector, and is wired as follows:
Solder Side | Parts Side
________________________________|___________________________________
GND | A | 1 | GND
----------------------------|---|---|-------------------------------
GND | B | 2 | GND
----------------------------|---|---|-------------------------------
+5v | C | 3 | +5v
----------------------------|---|---|-------------------------------
+5v | D | 4 | +5v
----------------------------|---|---|-------------------------------
-5v | E | 5 | -5v
----------------------------|---|---|-------------------------------
+12v | F | 6 | +12v
----------------------------|---|---|-------------------------------
- KEY - | H | 7 | - KEY -
----------------------------|---|---|-------------------------------
Coin Counter # 2 | J | 8 | Coin Counter # 1
----------------------------|---|---|-------------------------------
Lock Out Coil # 2 | K | 9 | Lock Out Coil # 1
----------------------------|---|---|-------------------------------
Speaker (-) | L | 10| Speaker (+)
----------------------------|---|---|-------------------------------
| M | 11|
----------------------------|---|---|-------------------------------
Video Green | N | 12| Video Red
----------------------------|---|---|-------------------------------
Video Sync | P | 13| Video Blue
----------------------------|---|---|-------------------------------
Service Switch | R | 14| Video GND
----------------------------|---|---|-------------------------------
Tilt Switch | S | 15| Test Switch
----------------------------|---|---|-------------------------------
Coin Switch # 2 | T | 16| Coin Switch # 1
----------------------------|---|---|-------------------------------
2P Start | U | 17| 1P Start
----------------------------|---|---|-------------------------------
2P Up | V | 18| 1P Up
----------------------------|---|---|-------------------------------
2P Down | W | 19| 1P Down
----------------------------|---|---|-------------------------------
2P Left | X | 20| 1P Left
----------------------------|---|---|-------------------------------
2P Right | Y | 21| 1P Right
----------------------------|---|---|-------------------------------
2P Button 1 | Z | 22| 1P Button 1
----------------------------|---|---|-------------------------------
2P Button 2 | a | 23| 1P Button 2
----------------------------|---|---|-------------------------------
2P Button 3 | b | 24| 1P Button 3
----------------------------|---|---|-------------------------------
| c | 25|
----------------------------|---|---|-------------------------------
| d | 26|
----------------------------|---|---|-------------------------------
GND | e | 27| GND
----------------------------|---|---|-------------------------------
GND | f | 28| GND
--------------------------------------------------------------------
