In my recent endeavour to get an RGB picture out of my SNES I had to learn a lot about the SCART standard and the ways in which the NTSC and PAL units differ. This wasn’t such an easy task as there is a lot of conflicting information on the internet about these things! This article will attempt to clear up any confusion that you may have about the subject and hopefully guide you in building or purchasing the right RGB video cable for your system.
DISCLAIMER – Much of the information in this page has been gleaned from the work of other people, and I have not managed to confirm all of it! I strongly recommend that you get yourself a multimeter and check things for yourself as you go, you might seriously damage your equipment otherwise.
You might have noticed at some point in your gaming life that the AV socket on the back of the SNES, N64 and Gamecube are exactly the same shape. In fact, they also have the exact same pin-out structure.
|1||RGB – Red **|
|2||RGB – Green **|
|3||C-SYNC / +12V *|
|4||RGB – Blue **|
|7||S-Video Y [Luma] ***|
|8||S-Video C [Chroma] ***|
|11||Audio – Left|
|12||Audio – Right|
* Pin 3 outputs c-sync on all NTSC systems and the PAL N64, but outputs +12V on the PAL SNES and PAL Gamecube. This is extremely important for choosing the right cable. Please see the section on general SCART wiring for more information.
** Not connected on NTSC Gamecube
*** Not connected on PAL Gamecube
Types of Video Signal
There are typically three ways of getting a video signal from your Nintendo console to your TV: Composite Video, S-Video, and RGB – that order is also generally considered to be from worst quality to best quality, but not all TVs and monitors support RGB or S-Video so your choice will depend on the limitations of your other hardware. This guide specifically deals with getting RGB signals for best quality.
It is very important to note that not all the Nintendo systems will support RGB natively:
|Native video support|
General SCART Wiring
+12V or C-SYNC?
OK, so you’re probably wondering why on earth there would be two alternatives for the output on pin 3 – the PAL SNES and Gamecube systems opting for a +12V supply while the others all go for c-sync. The answer has to do with the SCART standard.
You see, pin 8 on a SCART socket is there to switch the TV display over to that input automatically and select what aspect ratio the source should be displayed at – 4:3 or 16:9. The voltage supplied selects the appropriate mode.
|SCART Pin 8 Modes|
|+0V → +2V||OFF|
|+5V → +8V||16:9|
|+9.5V → +12V||4:3|
We can see then that Nintendo wanted a +12V output on their PAL systems (except the N64, for some reason) so that when the systems were switched on, the user’s TV would switch to displaying the correct AV input and a 4:3 aspect ratio would be forced. This functionality was not required on NTSC systems as SCART was not widely used in North America, so those consoles have a c-sync output in the place of the +12V.
This does present a problem if you want to use an NTSC machine on a SCART enabled TV though, as there is no +12V rail for you to replicate this functionality. The usual solution is to connect the +5V rail to pin 8 of the SCART plug to enable the auto-switching of the TV, leaving user to manually switch the display back to 4:3 from 16:9 in order to see the game in its original aspect. Unfortunately, that’s about the best you can do besides using an external +12V supply to power pin 8 of your cable, but that is pretty impractical. You can, as an alternative, select the OFF mode for this pin (which will probably default to a 4:3 aspect ratio?) but this means you will have to switch the display of the TV every time you turn on your console – so whichever solution you choose is basically personal preference. My TV remembers the aspect ratio override on each input, so my preference is to wire +5V to pin 8 and maintain the automatic display switch on the TV.
It is of critical importance that you do not use an RGB cable designed for an NTSC console with a PAL console (or vice-versa) as you may damage your equipment! Sticking a c-sync signal into pin 8 of your TVs SCART socket will likely not do it much good, so please be careful.
Pin 16 – RGB mode
The voltage on pin 16 tells the TV which input from the SCART plug to display on the screen. This is important as SCART often carries both composite video and RGB signals at the same time, so the TV needs to pick one. You’ll notice there is no voltage for selecting S-Video – some TVs will detect it automatically but often you will have to select it manually.
|SCART Pin 16 Modes|
|+0V → +0.4V||Composite in|
|+1V → +3V||RGB in|
The easiest way to get your +1-3V for selecting an RGB signal is with a resistor between the 5V rail and pin 16. Pin 16 has an impedance of 75Ω at the TV end, so using the equation for a voltage divider we can ascertain that a 180Ω resistor will give us around +1.5V.
Vout = Vin * (75/(75 + R))
Vout = 5 * (75/(75 + 180))
Vout = +1.47V
C-SYNC – What is it?
I recommend reading this page as it summarises sync rather nicely, there’s no need to reiterate it here.
My recommendation is that you should aim to utilise c-sync with NTSC systems (and sometimes the PAL N64) as they output it natively. On the PAL SNES it is usually best to use the luma signal as a replacement for the missing c-sync signal, and on the PAL Gamecube it’s best to use composite video as sync. You can buy cables that will extract c-sync from the composite video pin by using a “sync stripper”, but I’ll leave that up to you if that’s what you choose – my diagrams will assume you are not using sync-strippers.
If you have one of the original bigger SNES consoles then you’re in luck, you can get an RGB signal very easily indeed.
For best results, tie all ground points together and use separate wires for pins 5 & 6 from the SNES. This will minimise audio hum and other interference.
Later on in the SNES lifetime, Nintendo redesigned the motherboard of the SNES and combined many of the chips into one big chip to save costs. This console still outputs RGB natively, but it can be modified by bypassing the factory amp to boost the RGB signal for better quality and colours if you so desire. A guide for this modification can be found here.
If you have an NTSC region 1CHIP-01 or 02 board then pin 3 on the console will output c-sync as normal, however there also exists a rare 1CHIP-03 board that has no c-sync on pin 3. There is an easy fix for this in the same guide as for the RGB amp modification.
Whether you bypass the on-board amp or not, wire your SCART cable as for the normal Model 1 in the diagrams above. Remember to fix the c-sync if you have an NTSC 1CHIP-03 model system.
SNES 2 – Mini, jr.
The SNES Mini/jr use yet another motherboard variant, which doesn’t support RGB or S-Video natively. If you want to generate an RGB signal from this console you will need to follow this guide, being sure to also add c-sync back onto the multi-out as described in that tutorial. Once you have made the modifications you can wire your SCART cable as for the normal NTSC Model 1 SNES.
As you may have seen from the table, the N64 does not natively support RGB. To make matters worse, not all console revisions are easily mod-able to output such a signal. Here’s a quick step-by-step:
- Check your consoles motherboard revision in accordance with this guide.
- If your console has the VDC-NUS chip, you can perform the easy DIY mod found here.
- If your console is of a different variety, you must perform the much more difficult mod at the bottom of the compatibility page (see link in first bullet point) to enable RGB output. The tutorial for this more difficult mod also describes how the cable should be wired, so please follow those instructions.
There were many motherboard revisions for the N64 in all regions and it seems that many of them outputted c-sync natively and some didn’t – this article may help you discover what applies in your case and this thread also contains some useful information. I recommend reading up on the subject thoroughly and checking your N64’s output pins with your multimeter to be sure of what is going on, then making any necessary changes to the SNES RGB cable schematics above to suit your system. Depending on how you mod your system you may need the caps/resistors on the RGB lines, and depending on the motherboard revision inside your system you may need to fetch a c-sync signal from somewhere other than simply pin 3 of the AV out.
In my personal experience, I was able to perform the easier RGB mod from the retrorgb website (using only resistors on the output of the amp) on my NTSC N64 (board revision 03). Using an NTSC SNES RGB cable works just fine for that system once the mod is complete. Good luck!
As you saw at the beginning of the post, the Gamecube differs depending on whether you have PAL or NTSC console.
The PAL console will output RGB natively from the analogue port, hooray! Only problem is that official GC RGB cables nowadays command an extortionate price tag (over £50 at the time of writing on eBay), but aftermarket ones are available for a few pounds and will provide varying levels of quality. I bought a cheap one off eBay and it seems to work just fine, there is minimal audio interference and the picture is sharp (which is more than can be said for the cheap Xbox RGB cable I bought, but I digress…), so I’ll leave it up to you. The wiring for a PAL RGB cable, if you wish to make your own, is as follows:
The NTSC console, on the other hand, is a pain because it only outputs composite video and S-video from the analogue port. The S-video on the GC is surprisingly good, mind you, and many people will be pleased enough with it particularly when playing on a small screen. The “best” way to enjoy your GC, however, is with Component Video (I know, blasphemy). As with the PAL RGB cable, the component video cable for the GC is stupidly expensive – well over £100 on eBay at the moment, so this will likely be outside the budget of all but the most dedicated of picture enthusiasts. Remember also that the component video cable uses the digital out port, which not all GCs have (later ones didn’t ship with them) so make sure that your console supports it before dropping the cash for the cable. But enough about component, this guide is for people wanting RGB from their consoles…
You can get RGB out of an NTSC GC by following this tutorial from mmmonkey. The biggest problem with this project is that it seems the Nintendo Digital Video Cable it requires is even more elusive than the component video one (I can’t find one anywhere), and presumably just as bloody expensive. Still, it’s a way to do it if you happen to have one of those cables. That guide can also apparently be used to modify the component video cable to RGB – but, in my opinion, destroying one of those cables in order to get the tiny upgrade in picture over s-video is a waste of money.
Unfortunately there’s not much more to say about the GC, my recommendations are that if you live in the PAL region you should probably buy a cheap aftermarket RGB cable and you’ll be all set. If you live in the NTSC region, maybe the best option is to get your hands on a PAL console and RGB cable and modify the console with a XenoGC modchip so it’ll play your games – as that is all probably still cheaper and less effort than finding a component video cable…