Drivers? There aren't drivers per se to drive the board. Everything runs in DOS mode using the exe you get on the floppy disk unless my memory is going blank you can either feed it cd games or EX files. There's a lot of explore and I've just scratched the surface, keep me posted on any findings, please.
The basic PC-FXGA comes with "fxgav.exe" on the floppy. That just lets you boot PC-FX games that are on your PC's CDROM drive.
The next step is "GMAKER" with the compiler and tools.
With that you have to install the DOS drivers PCFXPIO.SYS and TGFX.SYS.
I believe that they allow a program that you write to access files directly on your PC (through PCFXPIO.SYS), or to access a CD in your PCs CDROM drive (TGFX.SYS).
The final step is "GMAKER PLUS" which gives you NXSBPCM.SYS and an upgraded TGFX.SYS, that allows you to create PC-FX CD images on your hard drive and have your program read them just as if they were a real CD.
So ... I've got all the drivers loaded, but I haven't actually created a CD image to run.
Well, actually, all my programming has been in Mednafen at this point, and the PC-FXGA has just been a testbed for running burned CD-Rs.