To quote, roughly translated: Today I'll write a tutorial to "fast-swap" between CFW 3.55 and OFW 3.70, using 2 HDDs... at the end of the tutorial, you'll be able to swap between the firmware just flashing a dump on your PS3 using Progskeet. (instead of downgrading and losing all data).
The first steps are not so easy, so take your time and go on, by the way, you must have some skill with Progskeet, and it must be 100% working...
125w ago - As a follow-up to the previousJaicraB JFW DH PS3 Custom Firmware videos came a video (below) by pdnked of a PS3 Slim Retail console running Rebug 3.66 Custom Firmware (which is actually PS3 OFW 3.66 with a few Debug files added) from Dospiedras1973 via Spanish site Elotrolado.
Dospiedras1973, EOL and user who has already managed to do the downgrade recently consoles INFECTUS using FAT for that necessary, has released a firmware that allows PS3 to version 3.66 with options debug a machine operative. Some clarifications are annotated by the developer: