Custom Fireware on the Fat PSP

[Bad Mr. Frosty]

Nice to see emulation is still not a taboo subject around this site.

Well, I have a nice old original PSP model. Updated the firmware the other day so I can play UMDs. However, upon reading up on at least 20 different sites about PSP emulation, it seems your not supposed to update the firmware if you want to put various emulators on the thing. In fact theres sites devoted to DOWNGRADING the firmware so the emulating is possible.

However, I've heard rumors that someone has developed a new brand of fireware that allows the system to still play official UMDs, and do the whole emulating thing too. Does anyone have a simple explanation as to how all this works from the ground up? If I don't know what I'm doing, what are my chances of totally screwing up my system?