PSP: 6.61 Infinity - Davee's 'Permanent Patch' for System Software 6.61 - Wololo.net
Update to 6.61 Infinity? : r/PSP
4 Ways to Upgrade Your PSP Firmware - wikiHow
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