Mapping two inputs to one button

[Chris99]

Hi,

I couldn't find any information about mapping two inputs onto one controller button.

I am playing a Mame Rom Spiderman game on the Mame 2003-plus emulator.

The game uses two buttons (a and b) to jump and punch. If you press both, you can do a special move.

Can I map button "a" and button "b" onto a third button on my controller somehow (just for this Rom) so I can just press one button to do the special move?

I tried going into the retroarch menu when the game was running but that only allowed me to map one input to each button.

The controllers are 8bitdo sn30 +

Any help would be appreciated.

Thanks!

[sleve_mcdichael]

@chris99 I'm not sure if this will work and if it does, it will be tied to this one controller, but you could try:

File: '/opt/retropie/configs/all/retroarch/config/MAME 2003-Plus/spidman.cfg' or ~/RetroPie/roms/arcade/spidman.zip.cfg
(Note: .cfg required in the first location, .zip.cfg in the second. Use one or the other of these locations, I'm not sure which takes precedence if both files exist.)

Edit: the folder names might not be exact. I'm not actually sure what the config folder for 2003+ is named, and you might have your roms in mame-libretro rather than arcade. But this should be close.

File content:

input_player1_a_btn = "1"
input_player1_a_btn = "3"
input_player1_b_btn = "2"
input_player2_b_btn = "3"

This (if it even works) would map A to buttons "1" and "3", and B to buttons "2" and "3" (substitute the actual button values for your gamepad for the buttons you want to use.) So 1 and 2 would be A and B individually, but 3 would be both of them.

If it works. Not at my Pi right now to test.

The problem with this is that if you ever use a different controller, this game will still be hardcoded with these button values, instead of using whatever was autoconfigured by EmulationStation. You'll have to remove or reconfigure the custom config file.

[Chris99]

@sleve_mcdichael Thanks! I will try this out.