kof 2003 cart questions.

PCB problems and fixes
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Chris
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kof 2003 cart questions.

Post by Chris »

Ok so. I have two MVS boards. One MV1ACH with euro SP-S2 bios 1996. One MV1C Asia Bios 1999. I have about 20 MVS carts which work perfectly fine with these two boards. So the boards work perfectly fine.

Yesterday i got a kof2003 english mvs cart. Serial 01376. No gold spot sticker. Original SNK roms/pcbs. This game produces funny glitches, from invisible fighters, to air walking, to sound glitches. Often the game will freeze or reset completely on the MV1ACH. Now comes the funny part, when i play this game on my MV1C(bios ver.6) it works perfectly fine. I cleaned the cart contacts, cleaned the MV1ACH slot. Made no difference.

Can someone explain whats going on? Perhaps kof2003, being one of the final carts isn't compatible with older bios versions? Anyone else who had similar issues with kof 2003?
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leonardoliveira
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Re: kof 2003 cart questions.

Post by leonardoliveira »

KOF2003 uses the NEO-PVC chip as decryption engine and copy protection.
https://wiki.neogeodev.org/index.php?title=NEO-PVC

The NEO-PVC chip contains 4K words (8KB) of internal RAM and of the three games which use the chip, only KOF2003 actually use the PVC internal RAM. And it's used exactly to store stuff like the characters positions on screen and other game engine values which affect the game operation during fights. Exactly what you would expect from a copy protection device, no?

If your cartridge was exposed to high voltages during it's life the ram inside the custom chip might have become damaged and is not storing the data properly. As I mentioned, only KOF2003 actually use the ram inside the PVC chip so you could maybe swap around the chip with a MSLUG5 or SVC Chaos cart as those two don't use the RAM.
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nem
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Re: kof 2003 cart questions.

Post by nem »

leonardoliveira, the cart is fine. The problem is that it doesn't work on the older MVS board.

I don't have a 2003 cart, so I can't test this.

You could ask someone to burn you a newer bios on an eprom and you could then try it on the MV1ACH.
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leonardoliveira
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Re: kof 2003 cart questions.

Post by leonardoliveira »

If the case is a compatibility problem, then it will likely be a hardware timing issue and swapping the BIOS won't do a difference.

I never heard of issues with SVC Chaos or MSLUG 5 (games using the same chipset) with older boards.
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Chris
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Re: kof 2003 cart questions.

Post by Chris »

That's the whole point, i couldn't get my head around that there is an MVS cart that does not work with a certain mvs revision. Someone on another forum suggested it might be due to the p-rom bank management of my mobo.
Anyway gonna replace that board and see if the MV1B will be more inclined to embrace kof2003. Thanks for the answers everyone anyway!
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leonardoliveira
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Re: kof 2003 cart questions.

Post by leonardoliveira »

Another suggestion would be sell the KOF2003 cart and use a KOF2003 single board (if you use supergun).
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