Remember, you can’t use this if you go 2.0! Stella PSP v0.1- This is a port of the Stella Atari 2600 emulator to the PSP. Original code by Bradford W. Mott, Stephen Anthony and Jeff Miller and many others. This PSP port was made by Alysa Habraken (aka Aenea). It’s not very optimized and not all games run or at full speed. Some have a little flickering, but this will be resolved in upcoming versions. Roms must have a .a26 extension and also they go in the ms0:/Stella/Roms. [via] Link.
Atari 2600 Emulator for the PSP