Installing Custom Firmware on a PSP : 9 Steps - Instructables
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
I tried installing 6.61 PRO C2 and infinity v2.0.3 on my psp 3001 (following the instructions on the CFW guide of this subreddit) but it just shows corrupted data when I disconnect,
Release: Infinity 2.0 – Enables Permanent 6.6x Custom Firmware for all PSPs! - Wololo.net
PSP update: 6.61, firmware, PlayStation
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PlayStation Portable (PSP) 6.61 firmware download
Sony Updates Its PSP Console with Firmware 6.61 – Download Links Available