Compatibility Problem

[hydr0x]

I tried to dump Powerpuff Girls: Paint the Townsville Green for the Game Boy Color today and I get a different dump every time. I cleaned the contacts and all other games dump just fine.

I'm using a Retrode 2 with the official PlugInGB as well as the latest firmware 0.18calpha3 on a Windows 7 machine. I read in another post that there were problems with another Powerpuff Girls game on an earlier firmware. I assume this problem is related. Any help would be appreciated, thanks.

[Matthias_H]

Does the game run fine? Just because it dumps some bytes differently every time doesn't necessarily mean that there is a problem. (Those addresses could be special registers of a mapper chip, or so.)

[BFC]

Nope, I fear it's not possible. Any GB(C) dump is unique and you can check the global checksum of GB(C) images in tools like ucon/gameheader or similar. If it fails your dump is wrong - no exception known when it comes to licensed games. When the retrode 1 was released there was a problem with games using Macronix-ROM chips causing random crcs. The GB Transferer suffers from the same problem. I remember I messaged you about the problem and in a later firmware update which significantly improved GB-compatibility this issue was fixed.

I tried now my retrode 1 with the old N64/GB-plugin and firmware 0.18c alpha3 with a MX-chip containing game (Toy Story Racer). It worked just fine. I also have Townsville at my parents' home in it's french version and I will check this too asap. I remember I had problems with the Powerpuff games as well because they also use the MX-chips. The final confirmation will be available as soon as I dump my copy but I guess the new GB-plugin suffers from the old issue again. I'm pretty sure my old plugin will dump the game in question without any problem.

[hydr0x]

Thanks, that's what I thought too, that GBC dumps are always the same. After all, doesn't the GBC Bootstrap actually check the internal checksum as one copy protection step? Interesting that it's apparently due to the MX-chip. I hope then that his can be fixed (again). Do you have a list of MX-chip games? I can test others then. Don't have Toy Story Racer but I do have another Powerpuff game.

[BFC]

The GBC just checks the header checksum, the global one is ignored. Still just like SNES all licensed games use a valid checksum (incontrary to the Mega Drive for example).

There are many MX-chip games. To name a few:

Power Rangers Time Force
Mickeys Speedway USA
Freestyle Scooter
Emergency Patrol
Tony Hawk 2
Dragon Warrior Monsters (UK)
Army Men Air Combat
Pro Pool
Monsters, Inc.
Zelda DX (at least version A)

[hydr0x]

Strange, Power Rangers Time Force was among those I dumped too and it had no problems. I own a few of those so will run more tests later.

[BFC]

Can you open your Power Rangers cart? If it also uses that chip we might need to search for a different reason. But it might also be possible our carts contain chips by different manufacturers. Or only a specific chip model causes problems.

[hydr0x]

Sure, no problem

Left is Powerpuff Girls, right side Power Rangers. As you can see Powerpuff Girls seems to use a A-Revision of the MX chip while Power Rangers doesn't. (click to enlarge)

[Matthias_H]

Is there any technical documentation on this MX mapper chip?

[BFC]

Interesting, the rev A chip is 44 pin while the other one is just 32. I never realized this difference. We need to do some more tests to check the theory. I will try to find some info about the chips.

[BFC]

The only information I found so far is on this website

http://www.seekchip.com/icstock-M/MX23C1603-12A.html#MX23C1603-12A%20PDF

The PDF-link does not lead to any useful datasheet. A proper documentation is only available for simiar chips of the MX23C1610 series but I don't know how useful this information really is.

http://www.datasheetcatalog.com/datasheets_pdf/M/X/2/3/MX23C1610.shtml