This guide will show you how downgrade your PSP to a 1.50 and play ISOs and UMDs that require 2.xx to play.Plus you can use all of the features of 2.71 without upgrading from 1.50.
Note:If your PSPs motherboard is a TA-082 this will not work with your PSP. Click here to find out if your board is a TA-082
What you'll need: PSP with 2.71 firmware. A way to transfer files into PSP Device Hook 0.46 (DevHook_FULL_Installer_v1.1.exe) (21.1Mb) Downgrader (15.6Mb)
Step one: Upgrade your psp to 2.71 if it isn't already.
Step two: Launch Downgrader2.71FULL.exe and follow the instructions. Note: If the screen doesn't turn red when you go to the photo menu it is safe to reboot your psp and try again.After finish, connect your PSP to PC or put the MS into MS reader.
Step three: Run Device Hook 0.46.When asked, select to install DevHook 0.46 with firmware 2.71 and then select your MS
Step four: Put any .ISO file in the ISO folder which should now be located in the root of your memory stick. Now turn your PSP on and go to the Game menu and run Decive Hook PSP Firmware Emulator. To run an ISO or UMD use these settings: (You need a Game or Demo UMD in your PSP for devhook to work) UMD SELECT: select the iso, cso, or umd you want to play UMD MOUNT: ISO ANY UMD UMD Version: no change Firmware: 2.71 CPU Clock: 222 MHz BOOT SELECT: Reboot XMB To return to 1.50 reboot the PSP.