I am trying to setup a GP-Wiz40 usb controller interface (link) and I am running into some problems. I want to get Mame4All up and running first, but it seems to only recognize the first 16 buttons (out of 40 theoretical inputs on the device), but I need 26. It seems like this is hardwired into the Mame4All code source, and not editable from any config files (see Sept 2003 Change Log entry). I know that the other inputs are functional, because Emulation Station can map them fine (I’ve only tested up to 26), but this doesn’t seem to propagate to Mame4All (possibly not covered by the RetroArch configs?).
My setup is a Raspberry Pi 2B with RetroPie 3.2.0 installed from an SD image.
A few questions: Does anybody have experience with getting Mame4All to see more than 16 inputs from a controller like this? Is this distinct to Mame4All, or can I expect to see this with the other Mame emulators as well? Is there a way to edit this value from the GitHub source, recompile it, and install it in place of the existing application? Is there a way to have the Emulation Station level controller configuration see the single USB controller as being a 2-player input (this is a side note, for the other emulators)?
I am pretty much a novice in RetroPie and Linux in general, so any help is greatly appreciated! Thanks all.