Well, I hate to use UMD discs on my PSP, and anyways, playing backup games (iso or cso) is far more convenient (3-4 games easily fit on the card), so I hacked my PSP some time ago. It used to have firmware version 3.40-oe (also a custom fw), but playing the latest games needs an upgrade, so I searched for a solution (FIFA 10 was the game triggered the action).
The upgrade contains two parts. First to update to 5.00 m33-6, then to 5.50 GEN-D
I. Upgrade to 5.00 m33-6
I found a nice tutorial at pspslimhacks.com:
It practically has 3 steps:
1. install 5.03 official firmware
2. install an run a so called ChickHEN exploit
3. install 5.00 M33-4 custom firmware
There is also a nice tutorial video included.
My biggest problem was with step 2 (running ChickHEN), so I followed some steps found in one of the comments
2.1. format memory card in the PSP
2.2. put the ChickHEN onto the memory card
2.3. restore default system settings
2.4, disable UMD auto on and UMD cache
2.5. after my 2nd attempt, ChickHEN was finally loaded (previously I tried it like 30 times, with no success)
So it was quite easy to upgrade, but games still did not start. (error 80020321)
I had to boot into recovery mode (holding R during boot), changed the UMD mode, not to require a disc to be inserted. All fine.
Discovered that there is a small update 5.00 m33-6 available, so I installed this as well.
II. Upgrade to 5.50 GEN-D
I followed the information at this thread.
Basically the announcement and steps for 5.50 GEN-D. Easy.
Actually there is and update for 5.50 GEN-D2, but I skipped it.
Time to play…