1. question:
The game Cruis'n USA runs really slow on my arcade box (Athlon XP 1800+ with a TNT2 card and 256 MB DDR-ram on Mame 0.63)...
why is that? Is it the emulator or my pc that makes it run slow?!
2. question:
How do you make Killer Instinct 1 + 2 work? When I try to boot it up it claims that some files are missing... any clue where I can find these??? And hey! I got the original Killer Instinct 2 (builded my arcade baox on a KI2 cab
)
Thanks to anyone who can help me out getting wiser on this 
cruisin usa, et al... requires more horsepower than is currently available commonly to play in MAME on a PC. some common suggestions - shut off frameskip (as it will make it look better and frameskip doesn't help this game) make sure your sleep is set to 0 in mame and you dont' have any background process runnin (virus scan/etc/etc)...
i'd need more info for your KI/ki2 prob, but I'm guessing you either don't have the .chd (compress hard drive images) or have put them in the wrong place... I'd try reading the docs regarding that... I guess you could dump the HD image yourself, but I wouldn't have a clue how it's done....
rampy