So here's my quick story.

I bricked. Hardcore. Downgraded from 3.71 M33-3 to 3.52, bricked. I cried. Literally. Anyway, I have no access to another PSP. At all. No friends, family, friends of friends had a PSP at ALL. Why i don't know, they are missing out... anyway, but I did have a card reader. I managed to take advantage of the Pandora exploit, creating a 'Magic' MemoryStick and a JigKick battery - ENTIRELY on my PC. No PSP was needed at all. So here is a rundown of what i needed and what i did...

NEEDS:
- A single PSP-Phat bricked and needing fix (duh)
- Internets access (for downloads obviously)
- A USB Card reader compatible with MSDuoPro cards (some only support MemoryStick and NOT MemoryStickDuo so be warned)
- One of the original revisions of the PSP battery, I have a PSP-1002 and it came with that.
- An MSDuo PRO (must be Pro, GENUINE) of 256≤>2GB size

PROCCESS (obviously dumbed down):
- Dissassembling the battery, clipping a certain pin on a chip to 'hardmod' the battery. This forces the PSP to load the 'bootsector' on the MemoryStick instead of internal flash0. This is PERMANENT.
- Making the "Magic" MemoryStick on the PC with the MSDuo in the card reader. This can be done with files all downloaded from the internet (*SEE NOTE BELOW)
- Applying the Pandora downgrade/flash0 repair, resetting the PSP to FW 1.50
- Applying Booster's Multi IPL Loader [and Sleep Fix] to the MemoryStick card reader in the PC


The repaired PSP will boot to XMB 1.5 normally :) holding L-trigger will load the Pandora menu, if the Pandora files are left on the MemoryStick.

With this method, you have a fully working/normal PSP - with a Pandora'd battery and MemoryStick! Downgrade you or your friends' PSP on the fly... as far as i know, this is totally working. The IPL loader compatibility would be the only problem, if applicable. The problem with this is that with your permanently-pandora'd battery, you MUST use the IPL loader-patched MSDuo EVERY time you boot your PSP.

Also, with the multi IPL patch, you can format the MSDuo - Booster's Multi IPL patch creates the hidden part of the MemoryStick at the beginning of the logical drive, which CANNOT be erased with a format either in the PSP XMB or on a standard PSP format (to make the MSDuo "normal"/non-pandora'd, you have to edit the partition table with dedicated software). However, if you want the ability to downgrade/unbrick to 1.50 on-the-fly, you will need about 3MB worth of data on the ms0, plus the 1.50 update EBOOT (labelled as UPDATE.PBP)


MY QUESTIONS FOLLOW:
- Would anyone like to see me make this into a guide?
- Is this against any rules of EP? Is it possible that this would incur any 'official' problems?
- The files that are found on the 'magic' stick, such as registry/kd folder and the msipl file, need to be downloaded from the internet - because the user has no PSP to make/build the files from firmware. Is it against EP terms to provide these files for download in this guide (as attatchments)?

Let me know guys. Cheers.


P.S. If this thread already breaches EP terms for some reason, I hope there's no hard feelings and locking it straight away will send the message well enough :)

P.P.S. I have recorded full credits for all the software/guide references too.