PSP 6.61 Custom Firmware Install on any PSP - PSP, PSP Slim, PSP 3000, PSP Go & E1000 | Page 19 | Digiex
Install or use custom firmware on any 6.39 PSP [PSP, PSP Slim, PSP 3000, PSP Go] | Digiex
Find Out Which Firmware Version a PSP Runs
Hack, Install Custom Firmware on Sony PSP-E1004 Street
Major PSP firmware update adds tethering, Media Go | TechCrunch
How to Update Your PSP Firmware
PSP FAQ - How Do I Update My PSP Firmware?
Picked up a PSP-1000 on firmware 1.0. Any reason to NOT be on 6.61? : r/PSP
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