Composite video

[Brianvgplayer]

Analog Y/C video shows odd artifacts and incorrect colors in both composite and svideo using the Mister Addons MikeS adapter.

[sorgelig]

Just latest release or older too?

[woj76]

My question exactly. Also:

• picture / photo?
• PAL? NTSC? Both?

[woj76]

I should add a few things - I just retested the core with the analog output (admittedly this is the one thing I forgot to re-check when I reduced the core clock speed) and on my old LCD TV (the only "analog" hardware I have at my disposal) the picture is spotless and I'd have huge problems telling it apart from the real hardware if I didn't know what is in fact connected to the TV. This includes games that do weird things with the TV signal through GTIA modes, like Space Harrier, that result in a flickering image on the HDMI output of MiSTer. (Generally GTIA hacks can throw off the up-scaler here and there, for example, one part of the Atari logo in the demo intro to Prince of Persia flickers visibly on HDMI, this has always been there.)

That's of course in the SCART RGB mode (the DB15 to SCART cable handmade) , I do not have the mentioned device to test it. So we need more details here...

(The final side remark - even on the original hardware feeding the composite or s-video signal through a SCART connector on a TV (tested with two different units) using one of those cheap popular composite / s-video adapters results in a horrible horrible picture (yes, also / especially for s-video).

[Brianvgplayer]

Just latest release or older too?

Latest release. Older release has no issues with composite or s-video. NTSC. I don't have any PAL compatible CRTs. By older hardware, do you mean Atari 400/800 or one of the computers in the XL/XE line? The 800 XL doesn't have the chroma line connected, IIRC.

Has anyone else tested with Y/C?

[woj76]

Right... This looks suspiciously like an NTSC TV trying to display a PAL signal or the other way round, but I am not a professional here. I am also 60% sure I have seen an artifact like this either at home on my 130XE doing some video mods or on the AtariAge forum, and here swapped chroma and luma signals echo around my head, or wrong csync source. So please, pretty please first triple check your cabling, loose plugs, core settings, TV settings, etc.

Personally, I did not touch any part of the core responsible for low level video generation (high level - yes), but there were some ANTIC touch ups by Mark in the recent pull request, and sorgelig did some system update changes related to video just before the release. The other possibility is that it got affected by changing the internal core clock. Another possibility - a long list of new options were added to the core, an old settings file might not work well with the updated core. So my kind requests:

• try removing / resetting the core's settings file (if you are not sure how to refer to Google, don't remember from the top of my head). Also double check all video settings (perhaps playing around with some too),

• try the core from this link (should be publicly available):

https://forums.atariage.com/applications/core/interface/file/attachment.php?id=1236654&key=8ecfade3f11b33439bca8660866e0e3b

If this core does work then it's the very recent internal clock change or the sys update. If it does not, then it is is likely Mark's ANTIC touch ups (the main problem here being that they are really needed for full compatibility with the original hardware and full ACID test compliance).

[Brianvgplayer]

I tried removing the settings files and I still have the same issue. I'll see if the different core works better. It's not an issue with hookups since the menus and other cores that support Y/C work fine. Would someone please test with the active Y/C adapter?

Edit: Just tried the core from the link. It displays perfectly in S-Video.

[woj76]

Ok, super, so this narrows it down to either @sorgelig sys update, or the halved internal clock, I will provide you with another core to test soon. If it is the clock then I probably missed some clock divider constant somewhere.

EDIT: Please try this core (I wish I would be able to attach it here directly): https://drive.google.com/file/d/1o2hWOOok17VjCdvW7p7YjWVOnT-B3a91/view?usp=sharing

[woj76]

Right, I think I see where the problem is, I see two more potential issues in the code caused by the reduced clock, I will make a test fix, but please test the previously linked core to confirm (I am quite sure it won't work).

[woj76]

Since I am now more than 50% sure the core I gave above for testing is not working OK with S-Video, here are both 800 and 5200 cores that I hope fix the issue (and actually two more issues I found that are related, one manifestation of which is that the disk version of Prince of Persia through automatic disk boot is not doing the expected thing). Please test both (just a boot to see that the screen is OK is sufficient):

https://drive.google.com/file/d/1yLH-Ub2bMuxE2Krz5GSe1uJefJh-TkCo/view?usp=sharing
https://drive.google.com/file/d/15FhYIypeX96MT069nDiyZ7aWuJIoqa2T/view?usp=sharing

If it does work I will make another pull request to @sorgelig (the fixes are rather critical anyhow...).

[Brianvgplayer]

Thank you. I tried both new cores and both work great in composite. Pac-Man is in the 5200 core and PoP is the DD disk version in the 800 core.

[woj76]

Thank you! Yesterday I actually tried bodging some wires to my MiSTer to hook it up to svideo to test myself, but I failed miserably.

[woj76]

@Brianvgplayer Would you please be so kind and re-test the two cores here for correct Y/C output? There was one more related issue reported (artifacting option not working) that I now fixed, but I need to know if Y/C still works after the fix (I still failed to connect Y/C on my MiSTer):

Atari800: https://drive.google.com/file/d/1d_a6JfpNpW5O3FH3-hBO4VgGpnDRYxJ5/view?usp=sharing
Atari_5200: https://drive.google.com/file/d/1-mGPWJZWInBz4acfQmaOMWawsUR9hgS3/view?usp=sharing