Supposedly, if you use the harness, the 8th button is shifted, but I've never tested it.
I have too many buttons for the harness to be my main source of buttons (7 buttons, plus start, pause, coin (wired to coin mech), coin (hidden under panel), tab (hidden above marquee), reset (under panel), and F2 (under panel), including several shifted functions).
Plus, you'll have to use joy2key for emulators that don't use gamepad buttons, because that's how windows sees it.