INES Mapper 151

iNES Mapper 151 represents the VRC1 on the Vs. System. Given that iNES has a bit to mark "For Vs. System", this assignment was erroneous and any games marked thus should be iNES Mapper 075 instead.

It is remotely conceivable that this is not true: FCEUX-2.1.5's and Nestopia-1.4.0's implementations of mapper 151 do not attach the 5th bit of CHR bank onto the lower 4 and instead emulate all registers as 8 bits wide.

However, no Vs. System games have more than 64KiB of CHR to verify the correct behavior against, and it is unlikely that a separate ASIC was made just for Vs. System games.

Pictures of the Vs. System Gradius module (here, scroll down to "Vs. Gradius") show the same VRC1 as in NesCartDB