what were all the other surface mount pads for?
I have four of the original TB pcbs. Two of them only have the one side populated that is used for communication. You will notice the dotted line going down the middle of the pcb. The one side is labeled as Tournament. This is the only side needed for tournament linking.
It is not known what the other side was used for. The two I have here that are populated have a battery and also the third S-video port attached which is labeled serial. It was rumored that the CPS2 system was also used in a "whack a mole" type game made by capcom. Perhaps it was used for driving a ticket dispenser? I hope one day to find one of those machines in a warehouse somewhere.
In the picture you will see three unpopulated pads on the tournament side. I actually had to buy the three chips and install them for the link pcb to work. I have no idea why the assembler did not install them. They are not uncommon components.
As an update for functionality they seem to be working but I need to get up with someone to test a set of four to make sure there are no issues. The only problem I see right now is a mechanical problem with the connector on our pcb. We will need to source a new one OR modify the pcb design to make the connector sit back a few more mm. Right now there is an excess in the gap of 2mm causing it to not fit in the B-board case. Also the original S-video ports have a round bezel around the plug that allows it to fit perfectly in the hole in the case. The ones we have now have a flat bezel. So we may need to move the S-video pads back 1.5mm so that it will fit in the case IF we can't find a supply of ports with the round bezel.