Use 27512 (64k) or 27256 (32k) eprom. The game it self needs 32k. Use XE super cartridge. PCB with Masked ROM 74LS74 74LS00 R1-R4 resistorpack. Remove Masked ROM Remove W1 / W2 Remove R1 / R2 Connect R2 right hole to 74LS00_pin-11 (CS/CE) Connect R1 right hole to 74LS00_pin-7 (ground)pin 20 with pin 22 Burn EPROM 32k file. Solder Eprom. Close cartridge. Place label. Done