Ok. All clear now. Thanks for the clarification.
I'm not a dev guy, so it's beyond my knowledge to modify the source code. I guess I have to prepare two set of config.txt, and reboot into the proper video mode when needed.
It's still obviously very distorted but what is odd that the pixel clock I'm using, 88.5MHz was the only way to get some semblance of an image. However according to the manual for my display it should be a pixel clock of 64MHz for 1024x768 60hz (resolution I'm using rn) and a pixel clock of 108.18MHz for 1280x1024 60hz
Any reason why the pixel clock is so off? Is my code still wrong? Ultimately I think this will boil down into me opening up the CRT and messing with the sync pots but I'd like to avoid that if possible.
Any further guidance or help is greatly appreciated 😄.
@solidshook not an expert, my understanding is that tvservice is used heavily in CRT guides/scripts, and this is only partially functional on pi4, since it is a call to the fkms firmware layer that is being depreciated.
raspberry pi are instead moving to the open source driver stack, which aims to be a more standard KMS offering, where the way to use custom modes is via DRM modesetting or xandr, the latter of which relies on X which retropie doesn't use by default, and i believe the former might not have enough flexibility.
still, an approach should be possible, with some work.
@jedcooper Sorry, never got around to fixing it. My menu widgets are already disabled, but the issue persists. I'm assuming that it's a similar issue to the one people are reporting with widgets, but not sure what more to do with that information unfortunately.
My other approach.. has been to emulate SNES on my Wii, haha. For an unrelated matter, I'm getting a VGA666 board in the mail some time. I don't expect that it will make a difference with this particular issue, but I'll give it a try anyway and report back if it makes a difference.
Besides the pictures and the seller's page, there's no much info about VGA666RGBs. They say it's compatible with Raspbian/RetroPie/etc., so I assume it works similarly to other GPIO analog video add-ons, using the standard vga666 'driver'.
For RGP-Pi, I remember it outputs RGB via Scart, so it might not be the first choice if your monitor has no Scart inputs. Not sure about the driver, though.