Famicom english conversions with with rebuilt audio circuits

The NES powerpak is a pretty cool device, but I can hear the difference between the powerpak recreation of famicom games with extra audio chips and the real carts. Therefore I decided to buy all the famicom games with built in audio chips that look fun and convert the rpgs into english. Here's one batch:



Madara and esper dream were the easiest. The pcbs use eprom wiring so it was just a case of split the rom, burn, solder in, and play:





Just breed was a pain. The game uses colour emphasis bits so to make it run on my rgb ppu I had to get help from thefox and dwedit on nesdev to hack the rom to make it run on my system. After that got sorted out I applied the english fanslation, still the game is mmc5 so a good amount of rewiring was necessary:



But it's all good now:



Moving onto something a little harder, gimmick! famicom including the same audio chip and circuit as the real cartridge:



This was built out of a 15$ ebay gremlins 2 famicom cartridge that by luck had the sunsoft 5b inside. To make the circuit work I needed to desolder the 5b chip to cut a trace underneath the chip which was grounding one of the audio pins. Then I had the fun task of soldering the sunsoft 5b back onto the pcb. Then I had to convert the cart, wiring a 32 pin prg rom into a 28 pin spot involved a little fun and attaching a17 to a non connected pin on the sunsoft 5b. I found a schematic of the gimmick sunsoft 5b audio circuit on a japanese website. I built the circuit not exactly the same using parts I had laying around which is why the cart is exposted and loosely soldered until the right parts so I can build it nicely and install it into a case. It really sounds good even using slightly wrong parts for the audio circuit. I needed to solder 3 tiny sunsoft 5b pins to build the audio circuit as well as wires to the two audio pins on the famicom cartridge pins. Also one other wire on a tiny sunsoft 5b pin for the prg rom to work.

And the last one which was the biggest pain is megami tensei 2:





The original pcb of this game is glob top forget trying to hand sold with that. I converted a cheap dragon ninja cart into megami tensei 2. To do this I needed to wire up and install flash roms (or eproms if you prefer) which requires rewiring to the maskrom spots. Also I needed to wire up a 28 pin ram chip, a battery circuit for the sram, and build the audio ciruit. Dragon ninja doesn't have an audio circuit since dragon ninja doesn't use the audio capabilities of the namco 163 chip. The audio circuit I built sounds 100% identical to the real cartridge:

http://www.youtube.com/watch?v=s1wJaL3pFTM

There's no megami tensei 2 fanslation yet but now I have a perfect reproduction cart ready for eproms if that ever happens.

Of course many thanks to the awesome people who made these fanslations that run on the real hardware as well as people on nesdev who posted the hardware details to help me figure this stuff out. Also the random japanese and polish websites that posted a lot of the necessary schematics.

 

One guy a few months back made an interesting hack along these lines. The finished product is basically Castlevania III for the NES with the extra audio from the Famicom version.

This guy accomplished this by using the infamous Gyromite Famicom to NES adapter, an Akumajou Densetsu Famicom cartridge, NES game casing, and an audio pass through cable that connects inline with the NES audio out. He even put the english translation of Akumajou Densetsu on the Famicom cart and a custom label showing the game roots.

Find it here.

 

I've made something better than that:



Batman return of the joker nes cartridge converted into japanese gimmick with the fme7 removed and replaced with a sunsoft 5b including the full audio circuit. The customer plans on using this in an av famicom with a converter so we'll wire audio straight through the converter.