Thanks for the info. Why does everyone make a big deal about no support for command keys if you don't actually need them? I was assuming that I couldn't actually quit mame on mac with the ipac.
I make a fuse because: "exit any game by pressing player 1 start and player 2 start at the same time." In the heat of the game, both you and your friend press the start button to continue, and BAM!!, no more game.
As a safety against this, I recomend placing a button that is nothing but the shift key so you're less likely to accidentally quit a game or bring up the TAB UI menu by incorrect timing. [shrug]
Others just set combos that are very very rarely used such as player1 button 7 being the shift key, and IPACshiftkey + player1 start being exit, but even that is too risky for me.
You don't even need the ipac shift key if you don't mind pressing button combinations. Just set the inputs in mame to key combos (plus leave the normal defaults), such as:
ESC or player1button1 + player2button4 + player1start for "UI Cancel" (what mame calls the exit the game key)
But I recomend using the ipac shift key feature, on a separate, non-action button. Maybe with macMame and ipac on a mac you have different defaults than my win system, but I doubt it. And it's only my option; up to you on exactly what to do.