Famicom Disk System extra sound channel on NES

[keiffer01]

I wanted to play with my disk system on my big screen tv, but since my tv doesn't recieve at all the Famicom signal, I need to use my NES using a converter and a Game Genie to play with my disk system. So the games work fine, but half the sound effects of the game are missing, since the NES doesn't have the extra sound chip in the pins like the Famicom. So I read on the net on how I could mod my NES to output the extra sound channel, and the say that you would need to solder 2 of the pins on the NES system to the bottom of the expansion port. Did anyone ever do this hack? And what pins would I need to solder to which in order to have the extra sound channel on my NES? Thanks

[michaelthegreat]

You need to have the audio from the famicom cartridge pin 46 get to the expansion port pin 3. Famicom cartridge pin 46 is audio out. Expansion port pin 3 on a nes is audio in (and mixes with the rest of the audio).

It's not just one wire, because you have to get the audio from the cartridge to the expansion port. On 72 pin nes systems, pins 16-20 on the cartridge are connected to pins 38-42 on the expansion port. Pin 42 connects to 16 and pin 38 connects to 20. Pins 51-55 on the cartridge connect to pins 6-10 on the expansion port. Pin 51 connects to pin 6 and pin 55 connects to pin 10.

Don't use pin 16 on the cartridge since the copynes uses it (not really important if you're never going to use a copynes). Pin 18 will be used as the example here because it's how I was taught and how I do it.

You need to modify your famicom game to nes system adapter to connect famicom cartridge pin 46 to nes cartridge pin 18. You also need a 100 kiloohm resistor and a 1uF or higher non-polarized capacitor. So, solder a wire to pin 46 on the famicom side of your adaptor (usually I do it where the cartridge connector solders onto the circuit board).  Solder the resistor to the wire and then solder the capacitor after that. Then solder on another wire and solder the 2nd wire to pin 18 on the nes cartridge side of the adaptor (be careful that you solder above where the cartridge connects inside the nes).

Now you just need to connect expansion pin 40 to expansion pin 3. There is nothing that plugs into the expansion port unfortunately. You can solder in a wire which is the best long term solution. For a while, I used a couple of mini-alligator clips that I cut off the tabs and soldered a wire to.

Of course, this will only work on a front loader since you don't have the expansion port on a top loader.

[MarioMania]

Ok, That was confusing..Does anyone have a hack NES with a Pic

[keiffer01]

Sorry Michael, but I'm also confused If you would have pictures of that hack that would maybe be easier to understand.

[UglyJoe]

It makes sense to me.  You basically need to get Famicom cartridge pin 46 to expansion port 3.  To do this, you route Famicom pin 46 to NES pin 18 (using wire, resistor, and capacitor) in your cartridge converter.  Pin 18 goes to expansion pin 40, which isn't what we want.  So, you have to connect expansion pin 40 to expansion pin 3.

So, Famicom cart pin 46 to NES cart pin 18 to NES expansion pin 40 to NES expansion pin 3.

[keiffer01]

Ok now I understand! But how do you know which pin is the first or last on the expansion port and the game converter? And is there a slight chance that it breaks my NES or Disk system? 

[MarioMania]

I still need pics, How the Mod was made

[133MHz]

Here's a pic of my NASA converter modded for FDS extra sound (click to see full size):

[MarioMania]

Can that work with Akumajou Densetsu ?

[133MHz]

Yes. Any game with sound expansion will work perfectly. Remember that you also have to join two expansion port pins together inside your NES.

[keiffer01]

Hey 133Mhz would it be asking too much if you could show me a picture of exactly which pins we need to join together. I kinda have trouble to know which one exactly is the first and all.

[133MHz]

This is the best I can provide at the moment:



I've been without a digital camera since I dropped mine and the motorized lens assembly got stuck, and I have zero possibility of getting one this week because of the incoming holidays (everybody's going to use their digicam to take pictures of their Christmas celebrations).

Anyway, just join pin 3 with pin 40. I've written down the pin numbers on the motherboard with a sharpie for ease of comprehension. NES cart slot is at the top of the picture.

[RGB_Gamer]

Here's a pic of my NASA converter modded for FDS extra sound (click to see full size):

I assume you use this with a top loader?

[133MHz]

I used it for a while with a modified NES (soldered the cart connector from a broken Game Genie to its board, making it a backloader) so I could play my FDS while I waited for my Famicom to arrive.

I could use it to play Akumajou Densetsu, Gimmick!, etc on my NES with full sound if I had any of those games.

[RGB_Gamer]

I used it for a while with a modified NES (soldered the cart connector from a broken Game Genie to its board, making it a backloader) so I could play my FDS while I waited for my Famicom to arrive.

I could use it to play Akumajou Densetsu, Gimmick!, etc on my NES with full sound if I had any of those games.

Lol, I gotta see that! back loader, wow, that's pretty awesome. Do you have pics and did you try FDS with that adapter? I remember seeing an NES clone once that looked like an NES, but had a famicom cart slot on the top (next to the back of the system). I assume it had an L-shaped cart connector. You put an NES cart in the system like a normal NES, and Famicom games on the top.