Those are games that uses 256 lines at mostly 55 Hz so it's neither PAL neither NTSC standard but in between. Setting groovymame to NTSC only will cripple those games.
On my TVs those games are using customs 256 modes that somehow fits into PAL preset on my TVs so I have large black bar at the bottom but at least I see whole play area. By default (arcade_15 mode) Irem, Midway games are cut of on the bottom and that's excepted.
On my TVs those games are using customs 256 modes that somehow fits into PAL preset on my TVs so I have large black bar at the bottom but at least I see whole play area. By default (arcade_15 mode) Irem, Midway games are cut of on the bottom and that's excepted.