Was also wondering if you happen to know which gun is the master gun and which one is the slave in a two gun setup Was also wondering if the vga boxes are identical. I siliconed them to a board that I have inside my cabinet. I can remove them if I need to (that's why I didn't use epoxy) but was wondering if there was some test I could run to figure which gun is the main (left player) and which one is the second (right player)
If think there is no really master-slave relationship. You need to set you 3-position switch gun to the 2 player position. With this, this gun will use the button 3 and 4 to fire and the other, the first and second. Remember to set to 1 de duallightgun option on mame.
Two ways to do two actlab lightguns. The old way is as Cananas said. The other way is enable -multimouse option instead.
Older way:
set 3 way switch gun to "player 2"
enable -duallightgun option
disable -multimouse option
maybe remap if needed
Newer way:
set both guns to "player 1"
enable -multimouse option
disable -duallightgun option
maybe remap if needed.
I don't know if there's any difference between the VGA boxes, but there might be. AFAIK, the box is where all the converting to USB occurs (location & buttons). So the box that came with the older gun (2 way switch) didn't need to worry about sending mouse buttons 3 & 4, unlike the newer box. So the 3-way switch gun might need to go to the newer box; the older gun probably could go on either box. I could be wrong though. Either way, there isn't a normal "slave/master".