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N64 RGB Mod and the OSSC

Posted: Sat Mar 07, 2020 3:42 pm
by dryja123
Hi Everyone,

Recently, I fell down a rabbit hole when I discovered the OSSC (open source scan converter), RGB modding retro consoles, and the Everdrive. I picked up an Nintendo 64 from my friend, RogerX, and it's my first time modding a retro console! I wanted to document my journey in hopes that it may inspire others to rediscover the N64, and possibly other consoles that they love.

Why RGB mod a retro console?

American NTSC video game consoles used composite video signal to deliver video as well as the signal to sync video the frames to the TV along a single wire. This had a dramatic impact on video quality due to compression and it impacted the color depth. RGB, on the other hand, breaks the video up into 3 different channels; red, green, and blue as well as a separate signal for sync. Cabling for RGB video devices used multiple connectors like a SCART cable, found in Europe and Asia, or cables with RCA connectors similar to component cables. By tapping into the RGB signals on an NTSC console you can dramatically increase the picture and color quality.

That is a very elementary over view on RGB and more information can be found on https://www.retrorgb.com

Ok, now that you've RGB modded your console but what is an OSSC?

The OSSC (Open Source Scan Converter) line multiplies your video signal with absolutely zero input lag. What does that mean? To put it simply, it will take the 240p output on the N64 and multiply the video by 2x (480p), 3x (720p), 4x (960p), and even 5x 1200p. This will allow you to achieve "pixel perfect" video quality on your HD or 4K tv.

More information on the OSSC can be found here: https://videogameperfection.com/product ... converter/

Now for information on the console modification.

I picked up a later revision N64 that was manufactured towards the end of the consoles life cycle. It was manufactured using the same video chip that you'd find on the fantastic N64 consoles. Unfortunately, the video chip used required a more advanced modification to break out the RGB signal from the chip.

I picked up Tim Worthington's universal RGB board: https://etim.net.au/shop/shop.php?crn=2 ... how_detail

Thankfully, Tim was thoughtful and created an adapter to solder directly to the DAC. The DAC on this N64 revision has a 0.8mm pitch and is super tiny. Pictures don't really put how tiny the pitch is on the chip so here's a picture to hopefully put it in perspective:
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I know what you're thinking. Soldering that ribbon to the chip is going to be a nightmare! Actually, this was the easiest part of the project. Start by laying down a little bit of flux on the legs of the DAC. This will help the fresh solder flow onto the DAC. After all, there's 21 years of air that has made contact with the chip.

After with fresh flux has been applied to the legs of the DAC I added some fresh solder to the tip of my iron and laid the ribbon in place. With the ribbon in place all that's needed to do is run the tip of the iron down the legs of the DAC while making contact with the pads on the ribbon. A few slow sweeps and the ribbon was on securely. The whole process takes roughly 30 seconds.
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Now with that out of the way, here came the most challenging part of the entire mod; stripping the ribbon cable and soldering it to pads on the ribbon. This was excruciatingly challenging because the wires needed to be stripped at the same length and the wires needed to remain together. Splitting the wires would have made it exceptionally more difficult. This took several tries because I kept stripping the wire or when I went to tin the wire the jacket kept melting away. I really appreciated the silicone jacketed wire that I use for other projects here. This entire process took me roughly a half hour to get done. It wasn't my cleanest work, but it passes. Keep in mind that these pads are super close together and it a very tight spot to get your iron in.
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Soldering the other end of the ribbon wires wasn't as challenging but the pitch was still pretty challenging. Still not some of my cleanest work but it's still passable.
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The next step of the process is soldering some wire from the output pads on the board to the video output on the console. Super easy stuff and was done quickly.
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and
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Finally, it was time to reassemble the console and button everything up.
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Cool, now that I went through all of that hassle what was the end result? I popped in Super Mario 64 and fired it up. Right away I was blown away with how clear the game looked. To put this in perspective imagine looking through foggy / dirty glasses and then imagine looking through clean glasses. The difference is really that huge.

Here's a picture of Super Mario 64 taken on my 4k TV. I had scan lines enabled on the OSSC and there's a reflection of my blinds on the TV.
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Pictures really don't do it justice, you really need to see it for yourself. This modification is really a no brainer if you love the Nintendo 64 and you want to play games in all of their glory. I hope you enjoyed this post! It was refreshing to modify something from my childhood instead of emulating the console or doing something with the Pi. In my opinion, there's nothing like gaming on original hardware.

Re: N64 RGB Mod and the OSSC

Posted: Sat Mar 07, 2020 9:04 pm
by wermy
Awesome writeup, thanks for sharing! I've got an OSSC but haven't taken the time to get the right cables yet, let alone mod my N64 to take advantage of it. I might need to make time for that now. :)

Re: N64 RGB Mod and the OSSC

Posted: Mon Mar 16, 2020 7:17 am
by dryja123
Being the perfectionist that I am, it was eating me up inside knowing that soldering job on the wiring wasn’t as good as I could get it. Also, I had concerns because I want able to properly tin the wires. You should always properly tin stranded wire because if you don’t, strands can fray off and make contact and short a neighboring connection.

Case and point:
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When I buttoned everything up I checked for continuity and verified that I had no shorts. When closing up the console the ribbon moved and some wire frayed off and shorted a connection. Thankfully, these wires were just carrying data and not power. I was noticing some picture artifacts that are now resolved with the re wiring job.