Is there a chance to update the Atari800 core? The current version (3.1) is old, the latest is 5.2. Sorry I’m asking here because the chance that someone will see my request on github is probably less than zero 
Yeah, obsolete versions of emulators is the biggest issue with RetroArch. I wish there was an easier way for the cores to be updated.
All I can do is wait and hope that someone will be willing to take care of it.
Someone submitted an update. If you would like to see it merged, build, test and report bugs: https://github.com/libretro/libretro-atari800/pull/123
I’m not a programmer, so I cant compile and test this update myself. I spoke with @jfroco, who’s responsible for fixing bugs in the Atari 800 core. But he said even he can’t merge the 5.2 update; Libretro Admin is required. Can someone from Libretro merge this?
Yes, but we should do some testing first, hence my previous post. If jfroco says it’s good, we’ll merge it.
Core has been updated to 5.2 and should be available through the core downloader. Big thanks to WizzardSK