ROM upgrades REversable?

Hey guys I have an Ultimate Mortal Kombat three that was obviously an upgrade from MK3. If I ever wanted to make this a regular MK3 again, can I swap roms back to the earlier version?

So my question is as follows: For Rom upgrades on PCB can they downgrade to original or is that a problem?

-ToeJam

ive heard that midway games have a key on them , pic chip or somthing it verifies that you have the right game , so no at least that what a customer was telling me when giving reason why he wanted original mk3 and not ultimate , but i dont see how that works since ultimate was a free upgrade since mk3 did so poorley

As well as the rom updates for the new version there are probably jumper links.
I dont know ? You could always burn a set from the mame dump of the earlier version, but there maybe other issues with the hardware.

UMK3 requires a different key chip, i forgot the exact part number.
U63 and U54 check for this chip, and if it is not the right chip for the game, the board will not boot.

I see. Well then, nuts to that.

Hey Razoola if you are here. I have a question for you. I have both CPS3 boards full kits for Jojo's Bizarre Adventure and Jojo's Bizarre Adventure: Heritage for the Future. I wanna get some sprites from Jojo's Bizarre Adventure: Heritage for the Future.

If you can help me make a sort of either Jukebox or a Sprite viewer. I don't wanna play them, but the CPS3 CD has 10 files on it. I wanna browse through for some sprites hehe. If this is possible please PM me on how I can accomplish this, since you are the GURU of all things Capcom

-ToeJam

Asure said:

UMK3 requires a different key chip, i forgot the exact part number.
U63 and U54 check for this chip, and if it is not the right chip for the game, the board will not boot.

Click to expand...

Asure, are we talking about a PAL-16 type programmable device, I think they are called EPDs ? (these give me the shits)

It's a 28 pin PIC IC specific to each game.

EDIT-In the MAME source there is some info on how it works.
src\machine\midwayic.c