First, here is a bit of history behind the meaning of the acronym, JAMMA.
In the dark ages of the Golden Age of arcade video games (1984 and before), game manufacturers operated in small exclusive domains where they designed game components in a way that best served their own interests.
Consequently, each had their own proprietary circuit boards, power supplies, and wiring harnesses. There was essentially no component interchangeability between a manufacturer’s arcade cabinet and an arcade cabinet made by someone else.
Thanks to the Japanese, around 1985, all that exclusivity faded away. The Japan Amusement Machinery Manufacturers Association (JAMMA) created some industry standards, particularly for the design of game PCBs. And, things changed forever.
The most important and influential of these new standards was the standard PCB pinout. Any gaming PCB that meets that pinout standard is what we now call a JAMMA board. You can see the JAMMA logo stamped near the pinout section of a JAMMA board. Almost all JAMMA boards sport that logo.
The wiring that connects the components of the game: monitor, power supply, control panel, speaker, etc. – the PCB is called the JAMMA wiring harness. The 56-pin edge connector of the wiring harness sits on the pinout fingers of the PCB.
There are many JAMMA terms that we hear and use frequently: JAMMA board, JAMMA harness, JAMMA edge connector, JAMMA cabinet, etc. At the root of its meaning there is nothing more than the concept of interchangeability of PCBs between cabinets of different manufacturers
And it’s the JAMMA standard PCB pinout (graphic below) that has made it all possible.
The following JAMMA pinout chart is basically a map of the 56-pin edge connector of the JAMMA wiring harness. When properly seated on the PCB, the edge connector pins will align with the pinout fingers on the PCB and your game will play.
When you’re shooting a game, you can plug and play the JAMMA PCB for your next favorite game. Plug-and-play simply means disconnecting the edge connector from one PCB and connecting it to another PCB.
And that plug-and-play process can continue over and over again, because there are now thousands of JAMMA game PCBs that you can play in your JAMMA cabinet. Thanks, Japan.
JAMMA PIN TABLE
Solder Side – Alpha Characters – 28 Pin – AZ, af
The solder side is the bottom side of the PCB. It is the side where the soldered connections of the parts are exposed to view. Few if any parts are located on the weld side. The solder side pinout is identified with alphabetic characters.
Parts Side – Numeric Characters – 28 Pin – 1-28
The parts side is the top side of the PCB. It is the side where the pieces are located. The parts side pinout is identified with numeric characters.
Usually, the printed circuit board is printed and the edge connector is engraved with the alphabetic and numerical characters.
EARTH – A, 1
EARTH – B, 2
+5VDC-C, 3
+5 VDC-D, 4
-5 VDC – E.5
+12 VDC – Ph, 6
KEY SLOT – H, 7
COIN COUNTER #2 – J
COIN COUNTER #1 – 8
LOCK COIL #2 – K
LOCK COIL #1 – 9
SPEAKER (-) – L
SPEAKER (+) – 10
N/CM
CN-11
GREEN VIDEO – N
RED VIDEO – 12
P-VIDEO SYNC
BLUE VIDEO – 13
SERVICE SWITCH-R
SOIL VIDEO – 14
SLAM SWITCH – S
SWITCH TEST – 15
CORNER SWITCH #2 – T
CORNER SWITCH #1 – 16
PLAYER 2 – START – U
PLAYER 1 – START – 17
PLAYER 2 – UP – V
PLAYER 1 – UP – 18
PLAYER 2 – DOWN – W
PLAYER 1 – DOWN – 19
PLAYER 2 – LEFT – X
PLAYER 1 – LEFT – 20
PLAYER 2 – RIGHT – Y
PLAYER 1 – RIGHT – 21
PLAYER 2 – BUTTON 1 – Z
PLAYER 1 – BUTTON 1 – 22
PLAYER 2 – BUTTON 2 – a
PLAYER 1 – BUTTON 2 – 23
PLAYER 2 – BUTTON 3 – b
PLAYER 1 – BUTTON 3 – 24
NC-c
N/A – 25
N/C
N/A – 26
EARTH-e
EARTH-27
GROUND -f
EARTH-28
Understanding the JAMMA Pinout Diagram:
NORTH CAROLINA – Without connection.
key slot – A keyed slot that aligns with an omission in the pinout section of the PCB.
This safety feature is provided to ensure that the power section is seated at the correct end of the pinout section. Reversing the edge connector and the power section sitting on the opposite or wrong end can cause irreparable damage to the PCB.
If the edge connector key has been removed, mark the connector on the “parts side” to help ensure proper seating.
power section – Pins AF, 1-6, e, f, 27, 28
video section – Pins N, P, 13-15
corner section – Pins J, K, T, 8, 9, 16
Controller section (joystick) – VY pins, 18-21
button switch section – pins ZB, 22-24