PSP 6.61 Custom Firmware Install on any PSP - PSP, PSP Slim, PSP 3000, PSP Go & E1000 | Page 19 | Digiex
How do I know what Sony PSP firmware version I have? - Ask Dave Taylor
4 Ways to Upgrade Your PSP Firmware - wikiHow
How to Update Your PSP Firmware
OFW psp & CFW psp blogs - Firmware 6.39 ME-5 was develop and release by PSP Developer Neur0n who has decided to release his latest PSP Custom Firmware 6.39 ME-5 for users
VERY EASY) Install Custom Firmware 6.60 PRO B10 PSP 1000, 2000, 3000 + DL - YouTube