Direct Video Output

akeley
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Re: Direct Video Output

Unread post by akeley »

Hodor wrote: Thu Oct 29, 2020 4:29 pm Notice that I need to set composite_sync to 0 on the Atari ST core because I suffer sync problems otherwise.
Thank you. For a moment I was wildly hopeful tha the above might be the key to solving my woes, alas...I just got a regularly rolling image, as it happens in general with cs=0 on my setup. With cs=1 the rolling on the ST core is more random and kind of "jumpy"

This issue is now really doing my head in. I basically copy-pasted your .ini and put it on my MiSTer. Why on Earth is it not working since we're on similar setups?

Could you describe yours a bit more? What TV are you using? I've tried it on two PAL Trinitrons (NTSC capable), from the post-2000 period. My cable is VGA-to-SCART from Lotharek (for MiST), connecting to RGB SCART in my TV. I did not mod it by adding that recommended resistor, did you?

Do you think internal core settings might play any role? I did try to change them before, when having stable picture on my PC VGA monitor, then going back to the TV. I've also tried a bunch of different TOS/machine configurations.

Finally my DAC is Logilink with the AG6200 chip. I've tried nearly all the other cores which are supposed to work on 15Khz CRTs and they are fine, with exception of Amstrad PCW which acts a bit similar as the ST one.
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Hodor
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Re: Direct Video Output

Unread post by Hodor »

akeley wrote: Fri Oct 30, 2020 10:20 am
Hodor wrote: Thu Oct 29, 2020 4:29 pm Notice that I need to set composite_sync to 0 on the Atari ST core because I suffer sync problems otherwise.
Thank you. For a moment I was wildly hopeful tha the above might be the key to solving my woes, alas...I just got a regularly rolling image, as it happens in general with cs=0 on my setup. With cs=1 the rolling on the ST core is more random and kind of "jumpy"

This issue is now really doing my head in. I basically copy-pasted your .ini and put it on my MiSTer. Why on Earth is it not working since we're on similar setups?

Could you describe yours a bit more? What TV are you using? I've tried it on two PAL Trinitrons (NTSC capable), from the post-2000 period. My cable is VGA-to-SCART from Lotharek (for MiST), connecting to RGB SCART in my TV. I did not mod it by adding that recommended resistor, did you?

Do you think internal core settings might play any role? I did try to change them before, when having stable picture on my PC VGA monitor, then going back to the TV. I've also tried a bunch of different TOS/machine configurations.

Finally my DAC is Logilink with the AG6200 chip. I've tried nearly all the other cores which are supposed to work on 15Khz CRTs and they are fine, with exception of Amstrad PCW which acts a bit similar as the ST one.
Well, sometimes weird things happen. For example, Tecmo core gave me a rolling picture before summer whatever composite_sync value I chose. But several months later suddenly works fine with great quality. Reason? I don´t know, maybe the core updates worked out my problem.

Having said that, my TV is a 15 inches PAL Samsung which supports NTSC over SCART without any issues. The VGA-Scart cable is pretty normal and unmodded, nothing fancy or expensive -I bought it on www.retrocables.es, a decent online spanish retro-store-.

I don´t think your problem is related with machine´s internal config so choosing different TOS or Atari ST models won´t do nothing, unfortunately. Have you tried another VGA-Scart cable? Someone once told me that they can be picky, so perhaps the key is there.

My DAC is a Ugreen, this one specifically https://www.amazon.es/gp/product/B00NBUTHJG/. I bought it because was thoroughly recommended in Atari-Forum. It´s cheap and works as expected.

Amstrad PCW core doesn´t work for me either on my 15Khz TV. Despite every option I choose it shows a very unstable and useless picture :(

I hope any of this gets you any help.
akeley
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Re: Direct Video Output

Unread post by akeley »

I don't really see how cables could be "picky", at least ones from a professional seller (Lotharek makes MiST boards). I doubt this is really the issue. We are also using the same cores. Perhaps it's something about the DAC, but mine works fine with everything else, so... who knows :)

Anyway, thanks for the info, at least I have some frame of reference now. Hopefully, one day...
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Re: Direct Video Output

Unread post by Hodor »

akeley wrote: Wed Nov 04, 2020 12:05 pm I don't really see how cables could be "picky", at least ones from a professional seller (Lotharek makes MiST boards). I doubt this is really the issue. We are also using the same cores. Perhaps it's something about the DAC, but mine works fine with everything else, so... who knows :)

Anyway, thanks for the info, at least I have some frame of reference now. Hopefully, one day...
Me neither. I was just stating some info I was told. When I first suffered from rolling picture my initial thought was the cable. In the end, the issue wasn´t related to it but to the cores themselves. Once they improved, everything begun to run flawlessly.

I hope you´ll ultimately resolve the problem. Atari ST core deserves a good RGB/Scart 15Khz video signal to be properly enjoyed. At least from my point of view ;)
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