I am able to run PSX ROMs. Currently have Tenchu and Metal Gear Solid (MGS). I have a 1080p HDTV and at first the game was full screen so kind of stretched and really poor quality (pixilated and tearing). So bad that you cant read text and character models look like blotches of color.
I searched around and changed the config file es_systems.cfg to have a 2 at the end instead of a 1: