This has been driving me nuts and I see that others have had the same problem, but I've not found anyone that posted how they fixed it, if indeed they did.
I'll start with a simple game....Lunar Lander. Controls are a rotate left button and a rotate right button. No problem..those work fine with pretty much any control I wish to assign to them.
The problem is with the thrust. The game expects this to be an analog (Pedal) input.
In past versions of MAME I've simply mapped this control to a button (Pedal 1 Analog Inc = Mouse1B0) and it worked fine. I did this for pretty much any game that needed a pedal input.
I'm using MameUI32 0.144u3 and I absolutely for the life of me cannot get it to allow me to configure the pedal to anything other than the following:
P1 Pedal1 Analog = n/a
P1 Pedal1 Analog Dec = Mouse0B1 or Mouse X or Mouse Y
P1 Pedal1 Analog Inc = Ctrl
It does not matter which of those three inputs I attempt to change, it always reverts back to what is shown above. I don't get it.
I obviously have mouse input enabled. I have tried configuring pedal input for both Mouse and Keyboard. Same result no matter which one I select.
If I push the Ctrl key on the keyboard, I get the behavior I expect in the game. Problem is, I apparently can't map that control to anything other than the Ctrl key.
Is there an INI file somewhere that I can manually force this for this particular game?