Function new_m238 

pub fn new_m238(
    prg_rom: Box<[u8]>,
    chr_rom: Box<[u8]>,
    mirroring: Mirroring,
) -> Result<Mmc3CloneMapper, MapperError>

Mapper 238 (MMC3 clone + $4020-$7FFF security LUT).

Errors

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