As i use quite a few custom controllers, connecting and disconnecting them (with stable IDs defined), i'd like to ask if i can add to existing key mappings through the MAME interface, without the need to edit files manually or map the specific button again for all of my controllers.
For example: for game X i have Button1 mapped as Joy3Button0, Joy2Button8, Joy1Button4, Kbd CTRL, Kbd O, Joy5Button13
Now i want to add to these mappings Joy5Button0
If i press ENTER, i have to remap them all again! Is there another way to add Joy5Button0 to previous mappings through MAME? (without editing files manually)?