Things You'll Need
Instructions
Open the MAME program. Press down on your keyboard to pass the games you have downloaded and press "Enter" on the "Configure General Imputs" option.
Go over "Player 1 Controls" and press "Enter." You can later repeat the task with all eight available players.
Press "Enter" on an option and the button on the keyboard or mouse you want to replace it with. Mouse buttons are used as a default by MAME for Buttons 1, 2 and 3.
Press "Escape" once to return to the previous options menu and a second time to go back to the main menu.
Use the same method to return to the keyboard-configuration screen and change the controls again if they don't feel well during play. Every previous change you've made will be shown in gray letters, instead of the system default's white.