Function new_m301 

pub fn new_m301(
    prg_rom: Box<[u8]>,
    chr_rom: Box<[u8]>,
    mirroring: Mirroring,
) -> Result<DiscreteMapper, MapperError>

Mapper 301 (BMC-8157 address-as-data multicart).

Errors

MapperError::Invalid on a bad PRG/CHR size.