nesdev.org

Been a lurker for a long time and wanted to share some photos of the internals of the "8bit Music Power" chiptune album recently released on cartridge by riki2riki.

http://imgur.com/a/F2WMH/all

I'm having some issues with the cartridge crashing after a few minutes on my otherwise-ultra-reliable NESRGB US toploader (it works perfectly on one of my stock US toploaders); I'm using a NES-JOINT board from an old copy of Excitebike as a converter. I'm still trying to debug the crashing..

In any case, enjoy. Let me know if you have any questions or need any other photos.

I'm quite certain the problems happen because the memory chips on the cart are 3.3V parts (that are not 5V tolerant also).

I'm surprised at how poorly built they are. Using the wrong voltage parts, excessively long wires, untrimmed throughole parts used in surface-mount applications, bodge wires, terrible soldering... hot glue?

Did these clowns have any idea what they were doing?

The good news is, if you wanted to fix the issue, the Micron M29F160F is a fully compatible, drop-in replacement and is 5V tolerant (and it's still in production, so you don't have to resort to "new-used" stock).

I just find myself wondering what the chip-on-board is.

Well, that and why it's got this little cartoon TV antenna of through-hole component rework.

Has the mapper chip been identified for this title? I'm guessing it's under the glop on the back.

So I found a few interesting tweets:

https://twitter.com/bakuten_do/status/6 ... 9832228864
https://twitter.com/taivatri/status/694169232393658368
https://twitter.com/zzr40092/status/695218455855796224

It looks like someone may have found a fix?

http://i.imgur.com/SDKTBJh.png
http://i.imgur.com/BCMGI06.png
http://i.imgur.com/gjmJueb.png

And it sounds like it may be an MMC3? I don't speak Japanese, but it looks like a lot of these users may have figured some things out and perhaps even dumped the ROM?

https://twitter.com/Xymiem/status/695822564459872256

http://vaot.mydns.jp/fc/fcrsm2.htm

Looks like the twitter finds I posted earlier were the fix. The cart is running stable now on my NESRGB US toploader.

Keep in mind you have to cut the trace and expose both sides in order to solder the resistor to each side. I ended up using a 68pF cap rather than 100pF.

http://i.imgur.com/m6tDVC7.jpg

Running stable now.

Thanks for the info. The rough translation there for the mapper is:

"MMC3 and is slightly different specifications"

It's likely some kind of weird pirate mapper, which would match up with the questionable build quality. I can confirm neither of the kazzo's mmc3 settings work for it.

Are the resistors and caps part of some hack to try to fix the voltage issue?

Looks like the correct mapper is TKROM, #118. kazzo can dump the cart and mapper change to 118 but due to the minor differences between TKROM and MMC3 proper there are a few graphical glitches running on powerpak etc. My only goal was to get it running on the powerpak due to the actual cartridge's poor build quality and voltage issues.

TKROM is just normal MMC3 with battery-backed WRAM, such as Kirby's Adventure and Mother/Earthbound Beginnings

If it has CHR ROM and the mapper 118 mirroring control (VRAM A10 = CHR ROM A17), it's probably TLSROM, like NES Play Action Football. How big is the ROM?

I believe the rom is not dumped right, file size is 768k but it runs fine in powerpak, which has less than that available. here is the info I can provide via nestopia:

The PowerPak has 512k for PRG and also 512k for CHR.

Thank you for the information, that explains things.