Ok, so I've just built my first cab and have been installing and configuring emulators. I'm using the Mala frontend, and various emulators such as Mame, Fusion, Stella, Project 64, visualboy etc. I must also point out that I'm using 2 x U360 sticks and all of my inputs run through those sticks (I'm not using any keyboard encoders). Each player has 6 buttons + start button + coin input, so there are no extra inputs to the sticks.
I have no problem exitting mame because I can just configure mame so it will exit back to Mala if I hold down P1 start + button 1. My problem comes with the other emulators. Some exit with Escape (from keyboard) and others exit with various other keypresses. In some emulators I have found a way to re-configure this, but only to other keypresses.
One idea I had was to take 2 wires from the escape key on my keyboard inside the cab, and wire to a button which I can fit on my coin door. I would rather not do this if there is another way, and I'm not sure if I can configure escape to exit every emulator. There must be an easier way. I just wondered what everybody else does.