I am confused about how the GPWiz49 pinout maps to joypad buttons.
I am in the process of trying to finish wiring up a control panel before our 4th of July party tomorrow (pressure, pressure!

) and I'm at the point where I need to start wiring up 2 GPWiz49s. I have the solder versions that I bought used. They came already soldered up to 2 Williams 49 way sticks. I've plugged them in and verified that the joysticks work properly. Now, I am ready to wire up 4 buttons per player, a start/coin per player, and 1 pause/1 esc (14 total) -- I'll be using leaf switch buttons.
I have a bunch of questions that I'd like to understand before pulling out the soldering iron.
1) Is there some default mapping from the pinout on GPWiz49 PCB to gamepad buttons that I should follow?
I.e. right now, the 49 ways are soldered into 1-8, G, G, and V+ on the PCB (essentially the leftmost 12 positions on teh PCB, looking from the top). Remaining pins are:
B D F H | J L N P | U D L R | G []
A C E G | I K M O | R L D U | G S
Does "A" map by default to a gamepad button? If I test the joystick in windows, there are buttons 1-28. How do buttons 1-28 map to the pinout above? A=1, B=2, etc? Some other way? What are the G G and S all the way to the RHS of the pinout?
2) Is there a guideline or a standard I should follow to make my life easier when I configure mame?
3) I am using Mala, so I think I need to make sure my admin buttons are one of the first 12?
4) When I go to map gamepad buttons in mame, do I really have to do it for *every* game, or can I set up a default to be applied to all games?
Thanks!