A-PAC Player 1 Start funky

[srakoczy]

Hello,

I have done several projects with I-PAC2s and never had a problem.  I am making a Spy Hunter Mame machine and bought the A-PAC so i could use pots to control the steering and acceleration.  For some reason, if I press player one and hold it does not act like a shift function like on the IPAC2.  So I went into the Windows USB game controller utility.  When I press P1 Start, "9" did not light up, it would light up very briefly when I released the button.  So I figured I had a bad button, so I pulled the wires and connected them together directly and again, "9" would light up very briefly when I separated the wires, not when they were connected.  I then assumed i had a break in a wire and checked for continuity and it was good.   I then took a wire from ground to P1 Start on the A-PAC itself, and the same result.  All of the other buttons are working fine, I press them and they stay lit until I release them.

Any thoughts on what to do would be appreciated.  Since P1 Start is not working, I can't use it to toggle with P2 Start to exit games!

thanks,

Steve

[PL1]

Since P1 Start is not working, I can't use it to toggle with P2 Start to exit games!

There's nothng wrong with your A-Pac.

The "Start1" input changes the selected buttons to the shifted set, buttons 13-28 in Windows.This behaves in exactly the same way as the I-PAC shift button.

When I press P1 Start, "9" did not light up, it would light up very briefly when I released the button.

P1 Start does not send an output until released, same as an I-Pac. 

The reason the A-Pac isn't behaving the way you expect is that it is a dual gamepad encoder, not a hybrid keyboard/gamepad/mouse encoder like the I-Pac.

A gamepad can output gamepad button presses and analog axes, but not keystrokes like "ESC".

The workaround:
1. Add a wire from the P2 Start button input "2STRT" (P2B9) to one of the unused button inputs on P1 side like "1B". (P1B12)
- When you press and release P2 Start, ground is applied to both inputs so the A-Pac sends P2B9 and P1B12 button presses.
-- Since P1B12 isn't used for anything, MAME ignores it.
- When you press P1 Start and P2 Start, ground is applied to the three inputs (1STRT, 2STRT, and 1B) so the A-Pac sends P1B28. (shifted P1B12)

2. Remap the exit key in MAME to P1B28 and everything should be good to go.   




Scott