Laptop to SCART using ATi Catalyst Control Center

Started by albino_vulpix, April 01, 2009, 05:47:24 PM

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albino_vulpix

I'm planning on building a cable to connect my laptop to a scart tv (no s-video on this thing), after playing around in ATi's CCC app, and finding options for 25 and 30Hz interlaced, and a composite sync option. Firstly:

Does anyone know what pin this composite sync would come out of? My guess is the v-sync but I don't know for sure.
And not as important, does anyone have any other info about this worth reading before I start building?

Fudoh

QuoteDoes anyone know what pin this composite sync would come out of? My guess is the v-sync but I don't know for sure.

99.9% H-Sync. Usually the H-Sync Pin is used for composite sync.

QuoteAnd not as important, does anyone have any other info about this worth reading before I start building?

Where do you live ? The last Extron Emotia VGA to RGBs Scart converter I saw on eBay.com went for $20. I wouldn't even bother with direct 15khz output from a laptop at this price. Especially since it's always a mess configuring the notebook's VGA output for anything incompatible with the internal LCD screen.

albino_vulpix

That certainly looks like a great box, however the one I could find on eBay is from the US, and getting it to Australia looks an expensive proposition (our exchange rate isn't too friendly.)

So h-sync is the pin to go. Thanks for that :)

albino_vulpix

OK I've wired up most of the cable (just the basics to get a picture) and I'm having some issues. I have the red, green and blue straight through to the scart pins, VGA pin 11 to ground, and horizontal sync to pin 20. I get a picture with perfect colour, but it appears the sync is off (rolling.) I then tried putting 444 ohms of resistance on the sync line (closest I had to a total impedance of 600 ohms) and had tghe same problem, but with a yellow tint. Continuity is fine, I remembered to set the output to composite sync, I connected the SCART voltages.

Any suggestions are appreciated.

antron

maybe you aren't really getting composite sync.  try the cheat: twist H and V together.

albino_vulpix

I had another play around with it, and tried H+V sync together, both with csync enabled and disabled. I couldn't get a stable picture. It didn't roll the way a syncless picture usually does (ie sending RGB through scart with the TV on the wrong channel) but a more random bit of picture. So I suspect the TV is only seeing jibberish on the sync pin.

I suppose this is because the sync a composite monitor uses is different to the sync a tv uses. So if anyone knows the difference between the two (impedance, p-p level), please post here (Google isn't being too helpful.)

albino_vulpix

w00t, I has picture! Just sitting around, and a thought hit me. So I get the half-cable thing from under the bed, plug everything in and fire up CCC. I click the minus buttons under the horizontal and vertical headings. Bam: beautiful green picutre (trying to fit a huge VGA donor cable into a scart plug; the colour cables kept breaking off.)

If I find some money, I'll raid the local Dick Smith tomorrow, make a proper cable and write up a little guide.

bigsanta

A bit late with saying this,but maybe you caould have just got a cheap scart lead and a female/male vga socket,lopped one end off the scart lead and just soldered your female/male end on and plugged the vga cable into this,or plugged this modified scart cable into your laptops vga socket then straight into your tv ?


Then you'd have less of a headache trying to squeeze that fat vga lead into the scart socket(i hit the same crap when i used one for a s video socket (8 pin mini din for a pc engine rgb mod for a friend))