Arcade PS2 Sync on Green - Simple Way to Remove the Greenish: There are monitors that natively support SOG (sync-on-green), and others that don't, the others that don't support it, they need some extra components to separate the video sync from the green channel, and that can be done with a LM1881 chip in.
So your screen does not support SoG? The cables exist, so that you can connect your PlayStation 2 (without anything else) to a screen that supports SoG.However, the PlayStation 2 must still output a VGA signal, which is not a video mode that is usually used by games. You can use GSM to override the video mode selected, but your mileage may vary because of how GSM works.These mods are simply alternatives, for those who own screens that do not support SoG and don't want to use a sync stripper (LM1881).I'm not sure if you know this, but RGB is not VGA. So if your running program does not use a VGA mode, then your screen will likely be unable to display the video input. Unless it is some special screen that supports those low-frequency RGB modes. So I have a GH-019 motherboard inside a SCPH39001R and after a lot of sleuthing around google I found this topic with a link to all the service manuals including one for my board.I used the VGA pinout below as reference (made sure to connect the wires on the proper pins as if I was viewing the image from the backside instead of the front). Connected ground to the copper on the side of the motherboard.
I connected the RGBHV signals to the spots labeled as such on the motherboard. I get a green tinted image, any thoughts? I know in some mods you amplify signals but I'm not sure how. I also made sure to enable RGB in the system settings and set my modchip to VGA instead of NTSC.Any ideas would be welcome! The plus side is I no longer have to switch video modes blindly as both VGA and component show an image while in transition.I'm also hoping I can configure OPL to play 480p compatible games through VGA and the rest send through RGB Scart.
Maybe, still crossing my fingers on that one. So if you capture the signals before it enters the SOGEN chip (IC206 iirc) you don't need to disable SoG as far as the above tutorial mentions.
As for the GH-019 board I was trying to use. It does away with the middle man all together and according to the schematic sends the signals straight from the GS chip to the IC211 which appears to have combined all the older chips into one. The only RGB signals I see on the board that are available before entering IC211 are three spots RB244, RB245, RB246 but each color signal is split up into 8 signals and I have no idea whether its possible to capture them all and combine them properly.Anyway, I found a SCPH-30000R console with a GH-015 board. The motherboard doesn't match the above tutorial but after studying the schematic I found the proper points and acquired a semi stable picture. The wires I'm using aren't properly shielded and I imagine I need to amplify the signals for it to be a strong VGA signal. My OSSC doesn't like the signal as it is but my old TV displays a solid picture at least (with some minor flickering and feint scrolling diagonal lines between screens). I'll upload images of the points I used so if anyone with a GH-015 board feels like continuing on go right ahead.
I'm going back to component my curiosity is fulfilled.
There are a few different kinds of sync signals that exist. For the kind you commonly see for retro gaming (RGBS), you typically have:. Composite sync (csync or clean sync): the horizontal and vertical sync signals combined into one signal and sent all by themselves as a standalone signal. This is generally the most desirable.
Sync on composite video: The composite video signal is used for sync. It's basically like taking the brightness (luma), the colour (chroma) and the sync, and combining them all in one signal. This is how composite video normally works.
The downside is that over the length of a cable, the chroma part of the composite video signal can couple in to the R/G/B lines and cause interference. This is undesirable. Also, some devices (like Extron devices) only support csync. Sync on luma: The luma (the green wire in component video, or one of the two signals in S-Video) is used for sync.
This tends not to cause interference, so it's normally fine to use, as long as you don't have any devices that require csync.There are some other sync types, such as separate sync (RGBHV, used for VGA) and sync-on-green (RGsB, sometimes used for VGA too), but those are less common in retro gaming.Anyhow, the reason why you only have certain sync types on certain consoles is because not all consoles output csync. For example, the SNES's output connector has a csync pin, but the Playstation does not. The Playstation does support S-Video, however, so you can use the luma pin on the playstation output for sync. It's the best quality sync available from the Playstation.
Some consoles don't even have that, forcing you to use their composite video output for sync.One thing to understand is that SCART cables only have one pin that is used for sync (the composite video pin actually), so no matter what sync type you're dealing with, the signal is going to get connected to that pin. That's why something confusing like sync on luma and composite sync can work on the same device, because it's different signals being connected to the same pin.An important note on sync strippers: these are devices that will strip off everything but the sync from the signal, resulting in csync. However, this does nothing to avoid interference, because these sync strippers are normally installed in the SCART plug part of the cable, all the way at the end, after the signals have already gone down the wire causing interference. The only thing that a sync stripper is good for is connecting to a device that can only support csync.