Yes. I dug up the information on what and why it's an issue:Fudoh wrote:A question about these quadrupled CEA modes. The original idea behind these is to raise the pixel clock above a certain compatibility threshold, right?
"The PLL supports abitrrary frequencies from 600MHz to 2.4GHz and the pixel clock is generated from this with an integer divisor.
The maximum divisor is limited, so when a frequency is too low to be generated we switch to using the OSC (19.2MHz) as the source with an integer divisor.
That probably explains the limited low frequencies available."
So, basically, in order to hit a specific resolution, you have to deal with the pixel clock limitations of the Pi 3. Any modeline you create (say for a specific system or arcade game) has to conform to the 19.2MHz auxiliary oscillator as an integer divisor.
For example, an R-Type cab is 8.2MHz. That's not going to work. You want R-Type, you have to crank things up past the limitation of the PLL divisor. I can't remember what the limit is anymore, but let's say it's around 13MHz, I think that's about right.
Retroarch (RA) is "aware" of the global resolution. If you set config.txt on the boot to be 3840x240, you have to tell Retroarch to expand all the way to 3840 to get a full raster. It's *razor* sharp and amazing looking. It also eliminates artifacting and gives you plenty of horizontal resolution to play with insofar as tweaking the sides goes.Does Retroarch internally see this kind of resolution? I mean, if you go into the video settings and chose a custom AR setting, where you can set the pixel count for both axis manually, what number does RA see here as fullscreen ? Can't try it right now with my Pi connected to a HD screen, which doesn't take any of the 240p resolutions through HDMI.
I'm not sure about the interaction between RA and RetroPie (RP). I have a lot of bad experiences with too many config files in RP, so I can't confirm for you if it behaves the same as plain old RA on a Pi. When you start RA through RP, it should be the same, because RA takes over, but the GUI browsing experience might work differently. Kittykats probably has better info on that.
Ok. Thanks for that info. I'll try to figure it out as I go.Regarding Retropie: here you can set the ES resolution globally through the config.txt, while you set the resolution for each emulator videomodes.cfg. This is where run command saves its settings. The run command option screen doesn't give you all the CEA modes for selection through the menu though, but you can easily edit the .cfg file by hand and just change the CEA mode to 8 or 12.
Sounds good. I'll let you know if I make any progress.I'll grab one of my HDMI to component boxes over the next days and give this a try on a small BVM.