Some of you may know this already, but i figured out a way to EASILY Downgrade/Upgrade the PSP system software all without the use of your PC. Once completed, that is.
What is required:
-PSP (no greater software than 2.00)
-2 MemorySticks (1x32MB MemStick and 1xLargerMB MemStick)
-PC (to set it up at first)
Okay, so what you do is, stick in your 32MB stick that came with your PSP and format it just to make sure everything is cleared out. Next add the required 2.00 OVERFLOW files to the MemoryStick, along with the 1.50 UPDATE Eboot (i also add my game saves to this stick just as backup, but that's up to you). Anyways, this MemStick is now complete.
Load ALL of your 1.50 & 2.00 files that you would normally use onto the 2nd larger MemStick. Examples are:
-all other EBoot files
-AVC Videos (yes, put those in there too even if your on firmware 1.50)
-All Your Pics
-Web Browser Files
-all other files
This one is important!!! Put the 2.00 UPDATE Eboot in the 'UPDATE' folder, like all updates and never delete.
Your Done!!! your PC is no longer needed to perform a downgrade/upgrade.
HOW TO USE:
Always keep the larger memory stick in the PSP, except for when your downgrading a 2.00, which then you would switch that with the 32MB Stick that has the 2.00 Exploit. Perform the FULL downgrade with the 32MB Stick in place. The when completed, switch back to your larger memory stick to play emus and ISOs. If you want to upgrade, just run the 2.00 update from your main memory stick (larger one). Remember the AVC videos and AAC tracks won't show up when your in 1.50 mode, but thats normal. Same as how, when in 2.00 mode, emus don't run. If done correctly, nothing will affect your PSP in any way when in either mode.
There you go. That's It.
Oops! One more thing. You can put the smaller, DOWNGRADER STICK as i like to call it, in the battery compartment of the PSP, it's simpler.
If this needs to be stickied, go for it.