Classicgamer wrote:I use my PS2 for both 15khz and 31khz with the same RGB cable. It still works when I unplug it from my Extron RGB interface and connect it directly to my tri-sync arcade monitor which, as far as I know, only accepts RGBS and RGBHV.
Which specific cable are you using, and has your console had a SoG-disable mod performed on it?
Classicgamer wrote:The narrative passed around is that the PS2 switches from sync on composite video to sync on green when it switches to 31khz, not that RGsB works for all resolutions. I'm not sure if it is accurate but either way, it would be easily solved with the Ultimarc PS2 RGB cable or a $15 Extron RGB interface.
If your monitor doesn't support RGsB at all, I would think you'd need both the Ultimarc cable
and an RGB interface; you would need the RGB interface to rewrite 31kHz+ RGsB to RGBS, and then you would need the Ultimarc cable to strip sync from composite (or luma; not sure which that cable uses) in order to get the RGB interface to accept the 15kHz RGBS (because it will completely ignore composite video and luma as sync signals).
Classicgamer wrote:I think it is possible that somebody just got confused with how you take sync from the green cable when you change the color space to Ypbpr. It wouldn't be the first time that somebody spread inaccurate info that got regurgitated.
I have first-hand experience with the RGBS<->RGsB switching behavior from time with the PS2 Linux kit. The official VGA dongle only has R, G, and B connected on the DE-15 connector (no separate wire for sync, no sync stripper). With the component video mode set to RGB, I get no signal while booting the console (with audio connected, I can hear the boot sequence), and then I get a 480p image once the boot disc loads (defaults to VGA 640x480).
Now, if the PS2 was outputting something weird, like RGsBS, which would allow for 15kHz RGsB, it's possible the monitor I was using at the time simply didn't accept 15kHz RGB and/or interlaced frames; but you could easily determine what the PS2 is outputting by connecting it to an OSSC with a regular sync-on-composite or sync-on-luma RGB SCART cable and making sure that automatic input switching is disabled. When you boot the console, you should get sync with the input set to AV1-RGBS and no sync with the input set to AV1-RGsB; and, when you enable 480p in a compatible game, you should lose sync with the input set to AV1-RGBS and regain sync when you switch to AV1-RGsB.
You could also partially test this behavior by using a component cable and an OSSC. When you start the console with component mode set to RGB, you should get no image with the OSSC's input set to AV2-RGsB (nor AV2-YPbPr, for that matter) until you either boot the PS2 Linux boot disc or blindly enable 480p in a compatible game.
Classicgamer wrote:It would be odd for Sony to choose to switch it RGsB as so few monitors accept it, and RGBHV is accepted by every CRT vga monitor. Not impossible though.
I don't think there was any kind of explanation direct from anyone, but no manufacturer of a console capable of 31kHz+ modes allowed anything higher than 15kHz modes via SCART--the PS2, PS3, Xbox, Xbox 360, Dreamcast, GameCube, and Wii all forcibly limit you to 15kHz over SCART. Some have posited that it's because feeding 31kHz+ to 15kHz-only displays can damage the circuitry or the tubes, but YPbPr component doesn't have similar protection, and I don't think there's been any confirmation that that is the reason for not allowing 31kHz+ RGB over SCART.
There's also the fact that Sony seemed to really like RGsB, and included support for it in many of their devices and displays, which might be why they decided to use that instead of nothing for 31kHz RGB, as we've seen with the Xbox, GameCube, and Wii.
Classicgamer wrote:I can test it with an official scart cable if anyone is interested. My monitor accepts 31khz via RGBs but I should lose sync if it actually switches to RGsB in 480p.
If your monitor accepts RGsB and doesn't require toggling an external-sync button or some OSD menu item, then you won't lose sync.