Complex sentence: Most revisions of the original system contain a discrete YM2612 and a separate YM7101 VDP; the functionality of these two chips were later integrated into a single custom ASIC (FC1004) for the model 2 and later revisions.
Split into simpler sentences: Most revisions of the original system contain a discrete YM2612 and a separate YM7101 VDP. The functionality of these two chips were later integrated into a single custom ASIC (FC1004) for the model 2 and later revisions.