Here are pics of my cp using an ipac2. I think that is a mini-pac, not sure though.
The grounds are just that and the joysticks of course go to the R,L,U,D. Buttons 1-6 on each side go to the respective player's buttons.
Like this...
1 2 3
4 5 6
Buttons 7 and 8 on each side go to the top four admin buttons. Start goes to the start button for each player. I have the coins hooked up to two buttons, each on the outside of the player start buttons. The two buttons on the inside of the player start buttons are the trackball's left and right buttons.
Hope that helps or is what you are looking for.