What Is It?
A chip on board cart.
64K of PRG ROM
16K of CHR ROM
Note: this board has bus conflicts.
The HC161 acts as a latch. It latches D0 and D4. Writing anywhere in the 8000h-
FFFFh range will set this latch using the above data lines. It is found only on the Super Mario Bros / Duck Hunt cartridge.
7 bit 0
The P bit selects the desired 32K PRG ROM bank.
The C bit selects the desired 8K CHR ROM bank.
Mirroring is hardwired on the cart.