Pandora's battery was quite a hit, but the sad part of it is that you need a homebrew capable PSP to create the battery. Well, if you are on a firmware below 2.80, then you can create one anyway. Here are the steps:

1. Get the 2.71 Update, and update your PSP to 2.71
2. Download the 0.4X Devhook Launcher + HEN-D and install them
3. Download the 1.50 US dump (http://www.psp-hacks.com/file/8)
4. Copy the dump to 150 in the dh folder
5. Download Pandora's Battery and follow the readme normally (make a magic memory stick, not a battery)
6. Go to devhook and set the language of your choice. DO NOT make a battery yet
7. Install 1.50 from the following link http://www.sendspace.com/file/a645il (thanks to Erikih for the link)
8. Make a folder in the root of the memory stick named registry and copy the 1.50 devhook registry to that folder
9. Boot into 1.50 from devhook and back up your serial, and then make a battery
10. Shut off the PSP and switch the WLAN up and take out the battery
11. Put the battery in and it should boot into 1.50, to boot into the menu, switch the WLAN down.
12. If it didn't work, when you make the memory stick, if on Vista, then run it as administrator.


Have Fun!

0okm has released his 2.80-2.71 Downgrader (TA-079 to TA-086)!

Brave enough to use it? Then go on to his site and download it!

REMEMBER THIS!

It is your own responsiblity if you brick your psp. Use the downgrader if you really know how to use it. If not, stay away from it to prevent bricking.

I cant use it yet... I dont have a 1.50 psp... Any1 want to help me? :)

All of you people know about the 2.80 downgrader(TA-079~81) by 0okm?

He is asking for the number of people requesting for a NEW downgrader!

A downgrader from 2.80 to 2.71! A high probability of downgrading a TA-082!

Come on! Need the downgrader?! Head to his website and give him your support!

Want 0okm to make your day? Then hurry down to his website!

http://0okm.blogspot.com

I will state this once and only once:

Strictly not for 2.81+ users, not meant for 2.81, 2.82, etc.

If you remove any part of the power supply during the downgrade, you will most certainly have bricked your PSP

Key:
Homebrew Available
No Homebrew Available
DAX Firmware

Sony Firmware

Homebrew Available
1.00- All but a few homebrew available

1.50- All homebrew available

1.51- No homebrew available-Upgrade to 2.00-2.71

1.52- No homebrew available-Upgrade to 2.00-2.71

2.00- User mode homebrew available
Non TA-082- Downgrader available
TA-082 users can update to 2.71 and emulate 1.50

2.01- User mode homebrew available
Non TA-082- Downgrader available
TA-082 users can update to 2.71 and emulate 1.50

2.50- User mode homebrew available
Non TA-082- Downgrader available
TA-082 users can update to 2.71 and emulate 1.50

2.60- User mode homebrew available
Non TA-082- Downgrader available
TA-082 users can update to 2.71 and emulate 1.50

2.70- User mode homebrew available
Non TA-082- Downgrader available
TA-082 users can update to 2.71 and emulate 1.50

2.71- User mode homebrew available
Non TA-082- Downgrader available
TA-082 users can emulate 1.50

2.80- User mode homebrew available-Kernel access found (Downgrader for Non TA-082 coming soon)

No Homebrew Available
2.81- No homebrew available-If exploit is found kernel access will be available

2.82- No homebrew available-If exploit is found kernel access will be available

3.00- No homebrew available-If exploit is found kernel access will be available

3.01- No homebrew available-If exploit is found kernel access will be available

3.02- No homebrew available-If exploit is found kernel access will be available

3.03- No homebrew available-If exploit is found kernel access will be available

DAX Firmware
(Can only be installed from 1.50)

2.71 Special Edition

Features:
Launch 1.00, 1.50 & 2.71 homebrew.
Launch ISOs directly from the XMB.
Recovery Menu.
Ability to load .prx modules.

3.02 Open Edition

Features:
Launch 1.00, 1.50 & 3.02 homebrew.
Launch ISOs directly from the XMB.
Launch any PS1 game downloaded from the Playstation Network on any PSP.
Launch UMD Movies from any region on any PSP.
PSP Region Selector.
O/X Main button selector.
WMA & Flash Enabling without internet access.
Recovery Menu.
Ability to load .prx modules.
Location Free and Korean Language have been removed.

A quick reference guide. Credit goes to the developers, keep up the good work

NOTE: Technically 1.51 and 1.52 do not have homebrew, but I still count them as homebrew compatible considering people can get to homebrew compatible firmwares from them.