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PAL composite connector

Posted: Sat Jun 04, 2011 4:42 pm
by Ashen
I'm trying to work out how to get PAL video to display properly on NTSC gamecubes.

Inside the composite video adapter on PAL GC's is a tiny board with a resistor and capacitor.
This is not present on NTSC composite connectors, its just a straight connection from the cube to TV.

So... Does anyone know what the value of the resistor and capacitor located inside the cable on PAL cubes is?

Re: PAL composite connector

Posted: Sat Jun 04, 2011 5:32 pm
by yamaharacer
thats just a pull up resistor and a capacitor for filtering the composite video signal. if you remove this two parts it also works without problems.

but to answer your question its a 71ohm resistor.

Re: PAL composite connector

Posted: Sat Jun 04, 2011 5:55 pm
by Ashen
Hmmm, interesting. Thanks Yamaharacer. Just to elaborate on my theory a bit...

While cutting apart GC motherboards we have found that if you remove the "R40" resistor (2.4k resistor) from near the AV chip you will get extremely crappy video output.
My theory at this point is that if we had a switch installed that could switch pin 15 on the av chip between 2 different resistances we may be able to get "playable" PAL video output on NTSC cubes. Its all just a theory atm, but I'll be testing it out shortly.

Re: PAL composite connector

Posted: Sat Jun 04, 2011 7:23 pm
by WiiPower
I'm trying to get this right:
NTSC GCs can't output PAL video modes? You are NOT trying to get NTSC output from PAL games, because your tv only supports NTSC?

Re: PAL composite connector

Posted: Sat Jun 04, 2011 7:59 pm
by Ashen
A stock NTSC cube will output PAL video. However the colors are all washed out and the screen flickers a bit. I'm simply trying to correct this. The screens I'm using support PAL 50/60 as well as NTSC.

Re: PAL composite connector

Posted: Sat Jun 04, 2011 8:53 pm
by WiiPower
Ah, so it's similar to the everything in red issue on wii with NTSC480i + RGB cables. The reason for that seems to be clear, it's outputting the NTSC s-video signal over the rgb cables and it all ends up on the red channel.

And PAL gamecubes display both without problems?

Re: PAL composite connector

Posted: Sat Jun 04, 2011 10:29 pm
by Ashen
I don't have any experience firsthand with PAL cubes. But the reports I get from others are that NTSC video displays fine on them.

Re: PAL composite connector

Posted: Sun Jun 05, 2011 11:30 am
by TPSNT
Yes NTSC on a PAL cube works fine with both composite and RGB output. And isn't the resistor in the picture 75 ohm and not 71?

Edit: Just took my cable apart to check:
Capacitor: 220μF 6.3V
Resistor: 75 ohm 5% tolerance

Re: PAL composite connector

Posted: Sun Jun 05, 2011 12:27 pm
by yamaharacer
yeah could be that its 75ohm i have just compared the color on the resistor with a resistor color sheme. i havent messured it.

Re: PAL composite connector

Posted: Sun Jun 05, 2011 12:57 pm
by TPSNT
I also haven't measured it, but purple, green, black is 75 ohm.

Re: PAL composite connector

Posted: Sun Jun 05, 2011 1:17 pm
by yamaharacer
but its purple, grey, black and thats 78ohm. doesnt matter you see how easy you can see other colors on such a picture. first i thought it is purple, brown, black. on my second view i mean its purple, grey, black.

doesnt matter.

Re: PAL composite connector

Posted: Sun Jun 05, 2011 6:06 pm
by Ashen
Thanks guys, That's why I didn't want to just go by the color values myself. Its to easy to misinterpret the values of each color band. It seems the general consensus is that its around 70-80ohms which to me seems to small a resistance to make a significant change on the composite line. Back to the drawing board I Suppose.

Re: PAL composite connector

Posted: Mon Jun 06, 2011 7:30 am
by LOCtronicz
It has nothing to do with that resistor. The video chip in a ntsc gamecube is different than that of a pal gamecube. I doubt it will be possible to make it accept pal and ntsc video image without a datasheet of the chip.

I've already played around with switching the video chips but no succes. When you play ntsc games on a pal gamecube the image color is fine but it doesn't fill the entire screen. I think it has to do with that ntsc uses 480 lines and pal 576 line.

The wiikey is region compatible but it doesn't force the video mode into the matching video of the gamecube region. Emu_kidid was busy with a wiikey menu replacement I hear. Although seeing how busy he is I don't know when it will get done. Would be perfect if we have a modified swiss which can load games directly fromt he wiikey fusion slot and load homebrew from gecko slot.