the buttons on the bezel i use a ipac i have 2 ipacs i use one for bezel buttons and one for control panel.
the buttons on the bezel red is exit emu/game. far left white is pause, one next to red left is enter, far right is tab to config mame and the other white right of the red button is a spare.
the blue button next to 1p is search in bigbox plus player 1 coin in mame and the other blue next to 2p is coin for player 2.
the 2 white buttons under the 1p buttons are for the spinner plus change image and change view in bigbox.
the two red ones at the bottom are left and right mouse buttons.