An easy 3.50 to 3.40 OE-A pack. Follow the tutorial in the included readme.txt to easily downgrade your PSP, and install Custom Firmware.
To use this downgrader, you will need a legal Lumines UMD. The EU (ULES00043), US (ULUS10002) Jap (ULJS00005), the original Lumines or (ULJS19005) The Best version. The original, Platinum, or Greatest Hits versions are all fine to use.
As well as a Phat PSP at or below firmware version 3.50.
None of this stuff works can anybody help me because,I don't have any special files or I don't know where to find the oldest version of PSP custom firmware!!!!!!