how do i back up flash files

I have a 40gb ps3 fat that is on 3.5fw i am going to downgrade and jailbreak the ps3 but i dont have a dongle or board yet. i want to back up my dev_flash3 and other files but am not sure how i do it. can i only back up those files with a file manager and a jailbroken ps3. or can i back them up with a retail un-jailbroken ps3 on 3.5fw using backup utility on xmb. i want to backup flash files because when i downgrade i want a backup in case i lose bluray playability. thanks for any help and info.

You can't back yours up on that fw as you have to be jailbroken before hand. From what I understand is once you downgrade to 3.41 modified pup downgrade to a lower original fw like 3.21 or 3.15. Then upgrade back to 3.41 using a sony fw of 3.41 for your region not the one that comes with the dgf.rar and it restores bluray playback.

Impossible, unless they find a solution to the problem.
As of now, either wait for a fix, or jail for 3.5 jailbreak to come out.
Don't downgrade if you want to to keep BD playback.

thanks thats what i thought but wasnt sure