My PSP is Japanese, the only ones that came with 1.00 firmware and since I've upgraded all the way up to 2.71. I'd like to upgrade to a custom firmware and would be all right stopping at 3.03 OE-C so I can watch videos in full res.
It seems like the logical way to go to 2.71 SE-A first, but the readme seems to assume you have version 1.50. Do I really have to downgrade back to that to make the install go smoothly?
Once I have a custom firmware, it seems pretty straightforward to go to any newer custom firmware. But I don't know the best way to go from official to custom.