Configuring MAME so a button is active when unpressed ?

[brianoneill]

Guys. I've tried and failed to get my Steering wheel pedals working in MAME. I give up !

But the steering wheel kinda works well on Outrun and the like. Problem is the accelerator needs a button to be pressed by hand. I can use the buttons on the wheel (old Logitech MOMO) but it gets tiring holding a button during the game.

Is there a way I can configure MAME(per game) so that a button is active when not pressed ? So in Outrun it would accelerate when I don't have the button pressed and ease off the gas when I do press it ? Weird I know but it's the best i got

[brianoneill]

I just figured it out. I turned on P1 Pedal 1 Reversed in Outrun.

[BadMouth]

See the driving cab info thread stickied in the driving cab subforum for pointers on configuring the analog controls in MAME.

For 270° wheels, set the joystick deadzone to .05 in the mame.ini file;
                 the default .3 means that you have to turn the wheel fairly far before it does anything.
                 Joystick saturation narrows the operating range of your wheel, i.e. you only have to
                 turn it halfway before MAME sees it as being turned all the way.  Set it to 1.
                 Controls are mapped in the same way as any other input in MAME (press TAB in game)
                 In the MAME menu under analogue settings, adjust the sensitivity to suit each game.
                 Most 270° wheel games require sensitivity set to the 100-200 range.
                 Digital settings adjust how key presses respond when substituted for analogue controls.
                 They do not affect analogue controls.  It also may be necessary to invert the axis in this menu
                 if MAME registers a pedal as depressed when it is all the way up and vice versa.
                 Do not map the pedals to PEDAL INC and PEDAL DEC!
                     Do not map the wheel to DIAL INC and DIAL DEC! 
                 Those are reserved for key presses being substituted for analogue input.

I guess I should do a more thorough guide mentioning inverting axis and calibrating the controls in the game's original service menu.