Sony PlayStation 3 Firmware 4.90 Download | TechSpot
PS3 Update to System Software 4.89: Here's a Full Guide for You
PlayStation 3 system software - Wikipedia
PlayStation 3: Sony releases Firmware 4.86 for their 13 year old console - HFW 4.86 released, SEN Enabler updated & PS3HEN to be updated soon due to no kernel changes! - Wololo.net
Can't connect my PSP to my PS3 (running cfw 4.81) tried different cables, is it an update thing? : r/PSP
How to update ps3 to 4.81 CFW - YouTube
Playerkp420 4.81 CFW Cobra 7.3 PS3 Custom Firmware is Released | PSXHAX - PSXHACKS