just sharing 6.61 PRO-C cIPL flashed PSP-1000 and PSP-2000 and 6.61 PRO-C Infinity PSP-3000 : r/PSP
32GB PSP-2003 slim 6.61 Pro-C∞ : r/PSP
Release: Davee releases Project Infinity - 6.61 Permanent Patch for ME & PRO CFWs - Wololo.net
PSP FW 6.61 PRO-C2 - Hackinformer Forum
PSP GO 6.61 Infinity Permanent CFW (PRO) Full Tutorial! 2017! - YouTube
[PSPHACKS 1.01] How To Install 6.60 PRO-C Fix 3 using Infinity 2.0.3 Permanent Custom Firmware - YouTube
PSP Custom Firmware 6.00-6.61
PSP: First hacks for the new Firmware 6.61 - PRO CFW & Downgrader updated! - Wololo.net
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,