Hold it hold it hold it.

So people are saying that Famicom games will play just fine in an NES. Umm, didn't some of Konami's games (Contra, Gradius and Castlevania III especially) have special chips or something in them, and that's why they had slight audio/graphical downgrades when they were localized? Will these play just dandy on NES with a converter or on a clone console like the Yobo? (I've heard CV3 had problems with the Generation NEX)