Infinity 2.0 released for the PSP, allows for persistent CFW on all models of PSPs on 6.60 and 6.61 | GBAtemp.net - The Independent Video Game Community
PSP 6.61 Firmware Update for Windows - Free Download
Brightness control v1.6 plugin for PSP ( works on 6.20 , 6.35 , 6.39 , 6.60 and 6.61 ) : r/psphacks
PSP Custom Firmware 6.00-6.61
PSP Custom Firmware 6.00-6.61
Release: Infinity 2.0 – Enables Permanent 6.6x Custom Firmware for all PSPs! - Wololo.net
4 Ways to Upgrade Your PSP Firmware - wikiHow
PSPHACKS 1.02] How To Install 6.61 PRO-C2 using Infinity 2.0.3 Permanent Custom Firmware - YouTube