How to enable Cheats within MAME:
1. When you download the cheat(version #).zip file you have to unzip that and place the cheat.zip file within the same directory as your MAME emulator folder.
2. Next start MAME, or the MAME64 application, near the bottom center you go to options, then Miscellaneous options, then turn Cheats to ON(Off is the default setting).....Remember to Save Configuration!
Then your good to go. When you hit Tab in MAME the Cheat(s) option will be there.