I'm sorry for the delay of my answer, but I'm having holidays, and I'm a bit far from my house. Actually, I'm at Tokyo... Very nice city, and very nice people too...
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Originally Posted by Stedy
@Ferix,
I will dig out one of my A500's at the weekend and try a few experiments.
I will feed the video through a summing amplifier so that I can apply DC offsets and see what happens. Will also try varying levels on the TTL Csync signal.
As one of the TVs I tested was sensitive to the sync signal, it should provide a good test case.
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Nice, I can't wait for viewing your work
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Originally Posted by Stedy
Have you tried the AC coupling of the composite video output?
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Yes, I tried It, and there nothing new... The signal is now coupled, but It doesn't work.
Quote:
Originally Posted by Stedy
Also, on the CVBS output of the Amiga, add a potential divider using a 36 ohm and 39 ohm resistor. This will reduce the amplitude of the composite video to less than 1V. Some video decoders, like the ADV7180 or the SAA7118 can not cope with a video signal that is greater than 1V peak to peak.
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I tried It using a variable resitor... It does nothing at all...
Quote:
Originally Posted by Stedy
With colour composite video, the chrominance adds 200mV on top of the peak white. On the A500 composite there is no chrominance information of course.
I really want to fix this, for my own satisfaction and to lay to rest the many issues experienced with RGB to SCART cables on modern TVs.
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I tested some other machines, like a MSX, a Sinclair Spectrum +2, and I got the same. It would be useful to have an "adapter box" for all those machines.
Quote:
Originally Posted by Stedy
On you TV, does it have the option to use RGB SCART or CVBS SCART?
The Akura TV I tested had these modes + Y/C (S-Video) SCART options.
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No, It doesn't. It only has the option to switch between the inputs, and I suposse It uses the fast blanking pin for doing the RGB mode change.
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Originally Posted by Stedy
The weekend is nearly here.
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Quote:
Originally Posted by Photon
Of all display devices, CRT TVs are the least fussy ones. [...]
Same with composite. It's "be happy if it works" times.
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It's sadly true...
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Originally Posted by Photon
If the "most common specs" of the major manufacturers of RGB SCART-compliant displays were known, there would be a possibility to make an Amiga-dongle with a female scart plug, containing some simple electronics to clean the signal up and adapt it to comply to the narrower standard - maybe with some jumpers or switches to adapt to individual display brands, so "everyone can make their displays work / try the same methods you are trying now".
And you could buy a simple scart-scart lead at the nearest consumer electronics store.
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That's the idea.
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Originally Posted by Photon
I think this is an awesome idea, and I would buy a bunch of those in no time flat
Please make this and sell me some, or at least provide a schematic so I can make them
This is a good thread, subscribing. If I can think a little about your test results I'll breadboard some solution together and try
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Let's see what finally happens...