Repairing Metal Slug X
This guide is for repairing Metal Slug X carts with dead Altera MAX chips. Either the game ROMs can be transferred to a PROGBK1 or the dead MAX chip can be removed or replaced. The first two methods need a hacked ROM which is linked at the bottom of this page.
A. Using donor PROGBK1
- Set jumpers correctly on BK1 board using this as reference: 
- Move all ROMs from the EOP (except for P1) to the corresponding places on the BK1
- Replace the BK1 P1 with a 27C800 containing the hacked ROM image
B. Fixing the PROGEOP
- remove MAX
- replace P1 with hacked ROM on 27C800
- patch D0-D7, /E /G etc.
- get ls74 and ls08 hooked up
- get ls139 hooked up for V ROMs
- whatever else, lots more to do compared to BK1 donor swap
C. Replacing the dead Altera MAX
New EPM7128SQC100 chips with the same package found in MSX are still being sold. Someone with a JTAG programmer could program a new chip with an equivalent configuration assuming someone eventually creates one.
($25ish from digikey? Any cheaper from elsewhere? Would cost about as much as a whole cart with shipping added in).
Download and burn to 27C800: