WTB 2-in-1 MVS Cart mod (Puzzle de Pon!/Puzzle de Pon! R)

[aoiddr]

I have a bootleg Puzzle de Pon! MVS cart that I'd like to turn into a 2-in-1 Puzzle de Pon!/Puzzle de Pon! R cart where you can use a switch(?) to change between them.
Anyone have any experience making one of these?

 

[ArcadeTV]

you will need roms that are double the size of the data, then you need to attach the greatest address line to the switch for ALL roms and connect them to either GND or 5V to select the first or second half.

 

[aoiddr]

you will need roms that are double the size of the data, then you need to attach the greatest address line to the switch for ALL roms and connect them to either GND or 5V to select the first or second half.

Sounds more complicated than I'm experienced with making at this point. I gather it'd probably cost me as much to have someone make one as it'd cost to just buy a real Puzzle de Pon! R cart, too. @_@

 

[ArcadeTV]

not really complicated at all... maybe pricey because of the amount of chips required. Maybe some roms of PDP and PDP-R are identical..? I'll have a look into it and let you know.

 

[kuze]

iirc the difference between the two games is one program ROM, so the switch is only needed for that chip. Check the mame ROMs to confirm.

 

[aoiddr]

Edited.

Actually, what I think I'm going to do is see about just converting it completely to Puzzle de Pon R.

 

[aha2940]

It seems to be easy to build, only different roms are P1 and S1, the rest seem to be the same.

Regards.