Thomas Cherryhomes has been hacking on the atari800 libretro core. Atari800 is an emulator that supports the Atari 8-bit computers and game systems. Much needed core options have been added to improve the overall user experience, including:

* System type (400/800, 800XL, 130XE, and Atari 5200)
* Video Standard (NTSC or PAL)
* SIO Accelleration (while this improves boot time, many copy protected games will fail to load if this is enabled)
* Internal BASIC (so that games that need BASIC can be played)
* Hi-Res artifacting (for NTSC games that utilize the high-resolution faux color artifacting, such as Choplifter!, and Drol)
* Boot from Cassette (needed for bootable cassette titles)

State saving is coming soon, not quite debugged yet, as well as trying to find the best way to add the keypads for the Atari 5200 controllers, with an eye to extending such support for other game systems of the same vintage that also sported keypads on their joysticks. Also, some build targets are not compiling (e.g. Wii, PS3, etc.), and this needs to be fixed.

The changes thus far, with the exception of the preceding paragraph have been merged upstream and accepted.