Can you map 2 separate buttons to do the same move?
Yes.
Press Tab (menu)
Select "Input(this Game)" menu
Highlight the desired input
Press Enter
Press the first button (shows first keystroke/button i.e. "Alt")
Press Enter
Press the second button (shows both keystrokes/buttons i.e. "Alt or z")
Say mortal kombat, 2 & 5 either would block?
Mortal Kombat (Rev 5.0 T-unit) -- ROM name "mk" -- needs default changed slightly for your layout.
* Map P1 Button 5 to Input "P1 Block 2"
* Map P1 Button 6 to Input "P1 Low Kick"
* Map P2 Button 5 to Input "P2 Block 2"
* Map P2 Button 6 to Input "P2 Low Kick"
Scott