NES ROMS

I am running firmware 3.95 (I know it was stupid to upgrade), but is there any chance I could play NES, SNES, and GBA games on my PSP slim. I have a 4gb. memory card…..
Thanks in advanced.
If there are any other details you need to know, I will update the question.
I know I need to downgrade the firmware, I just need a few good sources on how to do it.

written by The Purple Pie Man \\ tags: Chance, Could, Etc., Games, Play, Slim, SNES, There