thanks. i realised that a short while after making my post. I'm on a mac and it's also available in the mac utility. the only problem is it quit any application that was open when I pressed used it. i wrote my own short application that quit MacMAME when opened, and quicksilver triggers to open the application. I changed the shift key from escape to F1 and everything works well. this was a roundabout way of doing this, but it makes sure my frontend doesn't quit also if the player 1 and 2 start buttons are mashed while still in the frontend.