This is a simple controller interface that allows you to use Sega Genesis 3 or 6 button controllers for your project. This module has been developed for the Modular Super Gun project, but can be used for other purposes.
The interface take 5V power, and interfaces with other devices using dupont or IDC type cables. Here’s the back of the board where the controls interface is located:
A single jumper selects whether the interface is being used for 3 or 6 button interface.
A 24 pin cable, either 2 dupont 12 pin ribbons, or a 24 pin IDC cable can be used to connect this board with the JAMMA Headers board. This is the easiest way to get controls working in your JAMMA project.
24 pin connector on the Controller Interface 
24 pin connector on the JAMMA to Headers board
The interface uses Atmels ATMega 328 microcontrollers used in Arduino Uno, one microcontroller for each game pad.
I have created this interface for my old super gun project using Arduino nanos as well. I have provided the code as well as the design information on the following page. Use this information if you want to build your own variant of this interface.