Here is my JAMMA adapter for the Pana Twin Long. (Click on the picture for the full sized image )
You can see that I have opted for a CPS1 adapter to be soldered to the kick buttons (the three edge connectors below the key). Also pictured is a CPS1 to CPS2/3 adapter to give me the best of all worlds.
The simplest way to use this as a MAME stick is to make another adapter using the same fingerboard/pinout above and connect the controls to your I-Pac4. This would have the added advantage that the supergun remains completely original and unadulterated.
HTH
Cheers,
Ralph.
Coherance of posts inversely proportional to Foster's consumption!!!