nesdev.com

So, I once had a bootleg of the said game and noticed it was just a MMC3 board with an addtiional 74'161.
After checking the traces I came to this result:



So I got myself a TKROM board (MMC3 + PRG RAM + Battery) just to be sure.

I wired things up like I thought it would be with the bootleg but the game's not booting.
Connecting it like normal MMC3 I can dump the game fine and everything is equal when comparing both files (except iNES header, of course).

I tried wiring PRG A15-A18 ONLY to the '161 as well as MMC3 as well. Neither worked.

What am I missing or even doing wrong? Thanks in advance!

Well, that's definitely a major requirement, too, although evidently insufficient. (Only one output should be connected to any given wire, unless there's a way to make only one drive the wire at any given time)

My understanding is that mapper 189 actually comprises several major variations:
1- Several don't enable the MMC3 WRAM register before expecting to be able to select the 32K PRG bank. (Master Fighter 2 does appear to write $80 to $A001, however)
2- Several write to the $4020-$5FFF region instead of $6000-$7FFF region. (Master Fighter 2 does appear to write to $6132, however)
3- Several specify the bank in the lower nybble instead of the upper nybble. (Master Fighter 2 does appear to use the upper nybble, however)
4- Several use N108 clones instead of MMC3 clones

Interestingly, Mesen's and Nintendulator's implementations of mapper 189 causes Master Fighter 2 to crash, but Nestopia's doesn't. And there's nothing obviously different between their implementations... And NintendulatorDX says that it's not relying on uninitialized memory either...

I wish I still had the game board to check everything again. If anyone actually has a Master Figthter II or similar game of mapper 189, please post pictures of the PCB or even a rev-en if done. I'd highly appreciate it!

I don't think I've actually checked all the traces going/coming from the AX5202P so I'm most likely missing something. I just can't figure out what yet.

What's wondering me is that Thunder Warrior actually uses a PT8154 instead of a AX5202P as well as 74'138 and 74'175 + resistors, etc.

Does that mean theres 2 types of mapper 189? Or was my board that I had just a mapper hack of some kind?

I've seen at least two different PCBs for the YOKO shell of Master/Street Fighter II, none of them had a AX5202P. The most common has 2 COBs. The other had no COB but two chips marked PT8154 and PT8159 (which I'm guessing is the first print). There's supposedly a third one that has only one COB + a gate. Can't make out the part number from the blurry pic tho.

It'd be interesting to know how was your cartridge? I've definitely seen pirated release using an AX5202P.

The original version of the game, according to Hummer Cheng, is the one with the Street Fighter II title screen, and that one writes to $4132, FWIW. I would not be surprised to find that the ROM images that write to the $6xxx range are actually multicart extracts.

I sold all my bootlegs long time ago. I wish I still had it but I remember the cart shell looked like this:
https://vignette.wikia.nocookie.net/bootleggames/images/9/9d/MF2.jpg

I just hope I'm not mistaking it with Street Fighter II. Though both use Mapper 189.

The cart design was similar to what I drew (yay for Paint skills).

I might have the board you're describing, but mine has a defective PCB and no case. I'll check tonight.

Attached the original release. Plus what I assume to be the same board you're describing but with COBs.
These are not my photos.

If only the first picture wasn't so blurry.
What IC is that on the top left? If that's a 74'161 we're getting close.

It's definetely not the one with the PT8154 and PT8159 chips.

Here are my two non-Yoko Master Fighter II cartridges:
PCBs shots

On mine it's a 74'74

Thanks alot. That AX5202P really does look close/similar to mine from what I can remember.
I wouldn't be surprised if they had different PCBs for the same game at all.

Pictures of mine Master Fighter III (just title screen hack)

What's with the Street Fighter? Two MMC3 connected in paralel?