Picked up a PSP-1000 on firmware 1.0. Any reason to NOT be on 6.61? : r/PSP
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
PSP: 6.61 Infinity - Davee's 'Permanent Patch' for System Software 6.61 - Wololo.net
Tutorial] Install PSP 6.61 Pro-C Infinity Custom Firmware | GBAtemp.net - The Independent Video Game Community