How To] Downgrade Firmware on PSP Fat/Slim From 6.60 to 6.XX In Less Than 7 Minutes - YouTube
Complete Guide to PSP Custom Firmware | ReviveToday
Release: Infinity 2.0 – Enables Permanent 6.6x Custom Firmware for all PSPs! - Wololo.net
Infinity 2.0 released for the PSP, allows for persistent CFW on all models of PSPs on 6.60 and 6.61 | Page 2 | GBAtemp.net - The Independent Video Game Community