Author Topic: Nes (72-pin) to Famicom (60-pin) converter mod  (Read 59007 times)

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Offline kzd

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Re: Nes (72-pin) to Famicom (60-pin) converter mod
« Reply #60 on: May 03, 2020, 10:56 AM »
Gave it another go, and I eventually got it working. You do need to cut the trace connecting pins 57 and 58 on the NES side of the adapter, otherwise MMC5 games will not work correctly. I verified this using L'Emperur (US). I haven't fully verified that expansion audio works, since I don't have a NES ED nor any NES carts wired to send expansion audio, but once I get something to test that with, I'll report back.

Lastly, some tips for soldering this up:
  • Use a ton of flux. That helped me a lot with the jumper/bodge wires to the edge connectors.
  • Use kapton or electrical tape to tape off the edge connectors, leaving only a small work area at the very top. You don't want to get solder all over the pins. This is bad, for a variety of reasons.
  • Run the jumper/bodge wires underneath the resistors. This will get you the shortest wire lengths to the edge connectors, and requires you to cut away less of the plastic shell to get the adapter closed back up.

Have fun, and thanks for all of the helpful information in this thread!

Offline kzd

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Re: Nes (72-pin) to Famicom (60-pin) converter mod
« Reply #61 on: May 03, 2020, 11:27 PM »
Quick report back - confirmed expansion audio works by testing one of my NES conversions through the adapter on an AV Famicom.

One thing I am noticing is crazy audio buzzing, and I think it's due to the adapter. When I plug my N8 in, and run the same game off of that,  there's no audio buzz. Anyone have any ideas on what might be the cause?

Offline nuu

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Re: Nes (72-pin) to Famicom (60-pin) converter mod
« Reply #62 on: May 04, 2020, 04:09 PM »
Noise introduced by the adapter. Is there any unecessarily long wires, excessive solder or anything else that could act like an antenna?

Offline Bassguy

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Re: Nes (72-pin) to Famicom (60-pin) converter mod
« Reply #63 on: May 11, 2020, 01:00 AM »
I'm having some of the same graphical issues as Kunos does anyone have any ideas? I have noticed the Retrofreak NES to FC adapter has some different values of capacitors and resistors on its board I may see if I can borrow some of the design elements from that board to mod this cheaper convertor.

Offline twitch86

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Re: Nes (72-pin) to Famicom (60-pin) converter mod
« Reply #64 on: May 07, 2021, 03:02 PM »
Im digging out this post bc i was rebuilding my adapter these days..

First of all @Barawer - You soldered the coppershield to !!5V!! instead of GND - please change that and the picture!

Second i made a snapfit case for the PCB:
https://www.thingiverse.com/thing:1829293

Third... Can anyone really confirm that the 100ohm to pin 38 is needed and fixes bugs?
 I have no issues whatsoever in SMB 2 und 3 with only the copper shield to wired to gnd...

Offline Famicom.In.My.Blood

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Re: Nes (72-pin) to Famicom (60-pin) converter mod
« Reply #65 on: July 01, 2021, 02:11 AM »
Hello, new member here.

There is something I don’t understand with the Famicom/NES adapter, about the sound.

This thread talks about a mod to do to have all the sound after conversion, but I thought the problem was just for Famicom games which would be played on a NES, not for the contrary, because of Famicom expansion audio.

But here, I see it’s a NES to Famicom adapter which need a mod… so, some NES games sound don’t works properly on a Famicom too ?

Offline nuu

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Re: Nes (72-pin) to Famicom (60-pin) converter mod
« Reply #66 on: July 01, 2021, 12:09 PM »
No licensed NES game uses expansion audio, but some reproduction carts do, such as the Everdrive N8. So both 72-to-60-pin and 60-to-72-pin adapters needs to be modded.

Offline Famicom.In.My.Blood

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Re: Nes (72-pin) to Famicom (60-pin) converter mod
« Reply #67 on: July 06, 2021, 09:56 PM »
No licensed NES game uses expansion audio, but some reproduction carts do, such as the Everdrive N8. So both 72-to-60-pin and 60-to-72-pin adapters needs to be modded.

Thanks for your answer.

So, if I only use original NES games on my Famicom, no need for my 72-to-60 pin adapter to be modified, I’ll have all the sound properly everytime, right ?

Offline nuu

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Re: Nes (72-pin) to Famicom (60-pin) converter mod
« Reply #68 on: July 07, 2021, 04:53 PM »
Yes. You need to do another unrelated mod (which has nothing to do with audio) for MMC5 and a few other games to work as most adapters don't connect some pins used by those games. These games are very few though, and if you don't plan to play any of them you don't need to do this mod either.

Offline notsonic

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Re: Nes (72-pin) to Famicom (60-pin) converter mod
« Reply #69 on: October 08, 2021, 12:33 AM »
I just got one of these adapters from Console5 and I have maybe a stupid question. Are real games supposed to still work after doing this mod? I don't have an Everdrive but figured I'd do the mod incase I ever got one.

I have a Twin Famicom and with no mods to the converter, I played a real copy of NES Mario 2 to test it out and it worked fine. After doing the mods in the first post (cut 2 traces, 2 resistors, 2 wires, and copper tape) all I could get was solid yellow or green screens. I removed the copper tape and was able to get consistent garbled graphics, I don't think I got any sound. Then I removed the wires and resistors, same deal. I replaced the cut traces and now everything is working again.

So, is this expected? Do these mods stop real games from working?

Offline nuu

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Re: Nes (72-pin) to Famicom (60-pin) converter mod
« Reply #70 on: October 08, 2021, 11:01 AM »
No there is no difference between real carts and flashcarts in this regard, both should work and benefit from the mod, though all expansion sound 72-pin carts are unofficial ones (flashcarts, homebrew and reproductions etc).

You must have made some mistake somewhere. Recheck all connections including all pins.

Offline notsonic

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Re: Nes (72-pin) to Famicom (60-pin) converter mod
« Reply #71 on: October 08, 2021, 07:42 PM »
No there is no difference between real carts and flashcarts in this regard, both should work and benefit from the mod, though all expansion sound 72-pin carts are unofficial ones (flashcarts, homebrew and reproductions etc).

You must have made some mistake somewhere. Recheck all connections including all pins.

I'm an idiot. I was off by one on all the NES side pins. It's all good now.

On the front side, upper left corner, there's a plated via to the right of another via coming off pin 1/ground. This time I cut my copper tape around it just to be safe that I wasn't shorting that to ground.

Update: Castlevania III did not work. Pins 57 and 58 on the NES side have a trace between them. (You can even see it in the original post.) Rather than cut it, I just lifted the pins and have the wires connected to the pins and it's working fine now.
« Last Edit: October 08, 2021, 08:16 PM by notsonic »