I don't care either way for those particular drivers, I just wanted to point out there's a reason it's usually written the other way (even if on a 4 MHz Z80 driver and running MESS on a P4/Core/Core2 you're not going to see much difference). If you were doing a standalone emulator meant to run on a phone or GP2X or something of that nature, then you'd definitely want to get out and push ;-)