A few months ago I came across this youtube video showing Batocera displayed in 240p on a CRT Monitor.
This was using a rudimentary method using xrand to display the image in 640*480i.
Then right around the beginning of December i started talking to one of the developers of Batocera “rtiserra” about adding support for x86/x64 Linux kernel 15kHz video patches
These are the same kernel patches used by GroovyArcade.
These where then added to Batocera on December 16’th
GroovyMame support also got added.
At this time it only works with Ati/Amd that have an VGA port or DVI-I (DVI-I to VGA Adapter needed) or a few select Nvidia cards.
D0023R’s work is a continuation of Ansa86 Linux patches for Linux Kernel 4.11 and now supports Linux Kernels up to 5.10.
Here is Ansa86 original GitHub page that also links to D0023r’s repository Patches to enable 15KHz video output
Here is a write-up from “makoto” that explains how to patch the Linux kernel with D0023r’s Patches
Linux kernels after version 4.21 which meant it handles things differently (VSYNC). For the best experience you would want to install an older kernel where possible. However, you don’t have to but you will end up with 30 FPS interlaced resolutions in later kernels. for a work around disable VSYNC and enable max run speed 1.0x in frame throttling settings.
If I’m not mistaken this is now fixed in D0023r’s repository.
Well all off this is still in development and there are plans to include Switchres 2.0 by antonioginer for external emulators.
Switchres 2.0 is a continuation of Ansa86 work on Switchres
Custom EDID monitor/tv profiles that is used by GroovyArcade.
I can boot up in every resolution that D0023r’s Linux Patches support. Use Crtswitchres in Retroarch cores that supports it. Use GroovyMame for all my Mame needs.
As of right now it’s only me and another guy on the Batocera Discord channel that’s doing the testing but hopefully more people will join in and help.