Reply To: On Sony CRTs and D-sub-SCART cables
Do you know of a device which safely turns either RGBHV or RGBS into sync-on-CVBS RGB?
I think such a thing would be pretty much impossible since there’s no composite video signal left, it’s been stripped out, literally all there is is sync so where would you get the composite video from? I suppose you could transcode it on the fly from RGBS, but since we’re only talking about a handful of peculiar TVs here I doubt that anyone would want to make such a device.
I’ll address this myself, though it’s still a guess – sync-on-CVBS RGB does “use” pin 20 for R-G-B as well as combined sync, but also uses pins 15, 11 and 7 for R/G/B, otherwise it would display a composite video signal. So colors are carried over in two simultaneous ways with this RGB mode.
I’m not quite sure what you’re getting at here, pins 15, 11 and 7 are used for RGB. For an RGB signal you also need sync, this is taken from the composite video feed usually, on pin 20.
So, if you had composite video on pin 20 and no signals on pins 15, 11 and 7 you could get a composite video picture. If you had RGB on pins 15, 11 and 7 but no composite video signal, you couldn’t get anything because you need snyc for RGB.
When using RGB the composite video is ONLY used for sync, it is not used to extrapolate any colour information, something is clearly wrong with the sync processing circuit in the TV to cause this behaviour.
