Created attachment 226446 [details]
This is the current version of MAME for libretro. It is significantly more accurate for many games than the libretro cores of MAME 2000, MAME 2003, and similar, and supports all of the same games that modern versions of MAME are capable of running. The main caveat is that it doesn't support rewind, and that it is still considered somewhat experimental by the retroarch developers. During testing, I was surprised to find relatively accurate emulation of a wide variety of hardware that I didn't expect to work.
It uses a largely similar build process to the main emulators/mame port, so updating this port is relatively easy, and in fact, I was able to reuse some parts of that respective port.