My twin famicom with every upgrade imaginable.

[Drakon]

Since I've gained good experience building systems for other people I decided to pull my twin famicom out of the closet and have a bit of....fun with it.

I added the following to my twin famicom:

True RGB and s-video (using the crystal clear sony cxa2075 encoder), amped "stereo" sound with bass boost, replaced the rf jack with a s-video jack, replaced the unused B port with a n64 multi av port, added the ability to use a powerpak with the rgb setup. No holes were cut in the case I just desoldered unused ports to install all the ports I'd need. Also both the ppu and the rgb compatibility chip are socketed in fully connected precision sockets so it's very easy to restore the system back to running with the default composite ppu.

Pictures:





















The audio wiring was extremely tricky. It was difficult locating the traces that connect pins 45 and 46 on the cartridge connector (you need to disconnect these for the audio circuit to work). Also the audio circuit didn't sound as good as my av famicom (the circuit is designed for the av famicom). I fixed this problem by cutting the traces from the audio pins on the cpu and rebuilding the first chunk of the audio circuit based on the famicom diagram. Rebuilding the first section of the audio circuit (4 resistors) made the audio in the twin famicom identical to my av famicom when wired into the audio upgrade kit. Also building my own audio circuit made it so the system no longer mixes in the audio from the microphone on the second controller which is wonderful. I'm guessing that the fds upgraded audio chip is also disconnected but normal audio from the fds works fine. I can always wire up a switch later that will let me switch between my custom audio circuit and the original audio path.

[AznKhmerBoi]

Great mod and i like how professional you did everything, once again nicely done

[Drakon]

Great mod and i like how professional you did everything, once again nicely done

Thanks the professionalism comes from a couple of things:

1: Having the proper tools

2: Having a HUGE amount of experience with these systems.

I also just thought of my next addition to this system. The db15 on the side of the system has all the pins to wire up two controller ports for nes controllers. However the famicom db15 is a non standard plug. I plan to desolder the famicom db15, wire up a standard db15 where the famicom one used to be. Then I can build an external adapter from a standard db15 to nes controller ports. I can also build an adapter from the standard db15 to the famicom db15 incase I ever feel like using famicom addon...stuff.

[fvgazi]

Wow, the video on that is crystal clear! Nice job!

[Jontendo]

Then I can build an external adapter from a standard db15 to nes controller ports. I can also build an adapter from the standard db15 to the famicom db15 incase I ever feel like using famicom addon...stuff.

Sounds like an NES four score is about to get hacked.

Though kind of a moot point when running FDS images from the PowerPak, I wonder if the FDS motor could be converted to direct drive. The belts seem to be a real weak-link in those systems.

Nice work as always man!

[Drakon]

Thanks I'll probably just use the powerpak for fds games. Most fds games are only in japanese and barely any are translated into english so that can be a real crutch

Also I think I have controller ports in a spare nes case that I'll harvest and build into a small project box

[Drakon]

I did the following:

Removed the db15 expansion port from the system that's very uncommon.

Wired up a standard store bought db15

Mounted the new db15 so it fits perfectly in the case.

Built a standard db15 to p1 and p2 nes controller ports adapter.

Here's the pics:







When I get time I'll build the controller port adapter into a project box. I'll also build another adapter from the standard db15 to the famicom db15 that I harvested from the console.....incase I ever feel like buying a famicom addon device.

I also bought the switch I'll need to wire up to be able to switch between the original audio circuit and my super circuit. I'll probably desolder the composite video rca jack and install the switch in its place.

[vlame]

what about the disk side?

[Drakon]

what about the disk side?

[Drakon]

Audio wiring is 100% finished. The internals of this machine are 100% done now:





Unfortunately if I wire both the default system audio out and the kit audio out into the same connection the default audio out doesn't work. So when I switch between the two I need move the rca audio cable to the back of the system. It's a minor annoyance but it's better than having to install another switch.