Konami VRC6

This NES mapper that has two variants:

• VRC6a - iNES Mapper 024 (Konami PCB 351951)
• VRC6b - iNES Mapper 026 (Konami PCB 351949A)

You can read much more detailed documentation about the mapper at nsedev.

The Konami VRC6 mapper adds three extra channels which can be read about here.

(Source: nsedev)