Hi all I want to use this topic as it shows credit to Mednafen , although he clearly stated its a guess.. his guess was right( with the exception of b and c being switched ). The main reason I'm commenting is for the lack of info about the pc-fx on the net. This post has the most and I'm going to make it complete.
I have made a usb adapter and a plastic fitting for the pc-fx pad. Although I dont hang out here much you can try to contact me. I also can be found here
http://spawnlinux.dyndns.org/Bliss-Box/. If you find this info useful please use a link back to my site. Ok that being said here is what I know.
pinout facing the game pad plug, not the console.
1 2 3 4
0 0 0 0
0 0 0
5 6 7
1 +5
2 data
3 set low, data direction
4 latch
5 Gnd
6 clock
7 Gnd
the PC-Fx has an ID But I only worked with the pad.
examples:
Mouse = 0xD
Multitap = 0xE
Pad = 0xF
The pad uses the clock latch paradigm , so you wont be able to interface with it, without a micro controller of sorts. I'm not sure what the original clock speed is but with my 12 mhz avr, I set it to 6us in my loop and it worked fine.
Begin cycle.. Raise the latch
[loop this] 32 times lower the clock, wait 6 us
read a bit
higher the clock, wait 6 us
The first 16 are as follows I, II, III, IV, V, VI, select, run, up, right, down, left. and a few extra bits I didnt need to use..
the second 16 are like so
17
18 bottom switch
19 top switch
20
21
22
23
24
25
26
27
28
29 1 //0xf the ID
30 1//
31 1// not sure what these are for.
32 1//
end loop
Lower the latch
END