Downgrading PSP 2000 using Chronoswitch v7 from 6.61 to 6.60 - error CAAFFFFFCF7 · Issue #1 · DaveeFTW/Chronoswitch · GitHub
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
Why do so many people prefer 6.60>6.61? : r/PSP
4 Ways to Upgrade Your PSP Firmware - wikiHow
Sony Updates Its PSP Console with Firmware 6.61 – Download Links Available