Pac to jamma wiring question

[mammoth]

I just purchased a pac to jamma adapter (new and it was 1/2 the price of two bit) that's the good news  bad news it came with no instructions and i do not know where to connect the +5 and +12 wires to the pac board - (ground i think i can figure out) any suggestions as to best location to connect these wires. thanks guys - mammoth

[tommy]

Im not sure i understand, isnt the harness taking care of where the wires go.

Otherwise you have to look online for the pinouts of the jamma harness and pac pcb.

[SuperGunGuru]

It sounds like you got a kit that wasn't already put together. If it's not pre-assembled, check out Bob's page on Pacman to JAMMA adaptors.

http://www.homearcade.org/BBBB/adaptor.html

[Dav]

Im not sure i understand, isnt the harness taking care of where the wires go.

No, some of the better pac to jamma adapters have wires from the adapter to spots on the pcb, to bypass the ac circutiry.  I don't know where you need to attach the wires on the pcb.   I  prefer the kind that backfeeds the 5 volts from the jamma into the pac board.   

[mammoth]

maybe i wasn't clear enough. this addapter is so i can test pac boards on my standard jamma harness test bench. So what this adapter does is allow you to hook up a original pac board to a jamma powered harness. comes with three wires +5, +12, and gnd they need to be hooked up at a point past the pac A.C. in. - now anyone have an idea where the best place to connect them on the pac board might be(must obviously be past ac to dc part of the board). thanks

[Dav]

I think you'll find it doesn't matter  a whole lot.  If you read the bob roberts article mentioned by supergunguru you'll see bob feeds  the 12v in before the ac w/o any problem, same with the ground.  The 5 volts is more precise than the 12 so you'll need to attach it after the AC or backfeed it in through the +5 output. 

I believe if you go to 2bit's site and look up the adapter they'll have the manual on line and you can hook it up exactly like is recomended.  However if you're going to be testing different boards I would recomend seeing if it's possible to modify your adapter to match Bob's backfeed design to avoid using any wires.  I use a backfeed adapter all the time w/o any problems.