Reset the PSP firmware?
Has anyone tried removing the internal battery, if there is one, to see if the system resets itself to the original firmware. I'm talking about the battery that keeps the clock ticking even when you take the battery out of the psp. Just a question, please dont flame.
The firmware does not rely on a battery ;) Also it is saved on some technical name that escapes me and is thus not possible.. plus the firmware updates overwrite the original ones, leaving no trace of them
If I am not mistaken, the Firware is saved to a EEPROM. Just like your BIOS in your computer, if you update it (which, yes, it is possible in case you didn't know) removing the battery won't reset it. See this chip as a little disk containing X.XX space (I think, not sure though, that the PSP has 1024kb of space, but like I said I might be very wrong here).
This is the reason why (related to the BIOS example) I think it is not possible to flash (or downgrade) the PSP with a deincremental number. On a computer if you have BIOS version 2.00, it is only an update (so add-ons) from the version 1.5. Reflashing to 1.5 will create a corrupted BIOS. To be able to downgrade you have to reflash with the mainstream version, which is the version the BIOS been released with (or if you prefer, the VERY first version of the BIOS software) and then reupgrade until the desired version.
But this is part explanation and part theory. Don't necessarly take everything I say in consideration.