trackball +5v --where to get it from?

i have a happ TB that i'd like to run off my jamma harness.
i understand it needs +5v, which is not normally supplied to the control panel.
So my question is: from where can i take +5v from?
Can i take it directly from one of the +5v pin on the 28/56 jamma connect, or would that be too much of a drain?
Any assistance would much appreciated

I'm no expert on this but I don't see what's the problem in taking them from the JAMMA +5V pins as you suggest, so I would take them from there if I were you.

that seemed like it'd work, but not being an expert or anything, i just wanted to make sure i wasn't totally off
thanks again --let you know what happens.