Help wiring mouse buttons

[Magnet_Eye]

I am using Opti-pac to connect my trackball. How can i wire up mouse buttons to arcade buttons?

[OSCAR]

The Opti-PAC has a mouse button header along the short side.  Wire your arcade buttons to that header just as you would to the I-PAC, with one wire to the respective mouse button screw terminal and the other to ground.

[Magnet_Eye]

You mean where it has the  "Player 1 L-R, and Player 2 L-R" connectors?

I wasn't sure what these were for.

EDIT: Ok, now that I took the time to read the documentation on the ultimar.com site, i see that those are right/left mouse buttons.  

Thanks for the tip Oscar.