How to Downgrade from 1.50 – 1.00
I am not held responsible if you brick your PSP.
To use the button changer you have to use it before you downgrade
1.Make sure that you have a 1.50 version PSP. This can be check in the settings of your PSP. Settings> System settings> System information. Also make sure you don’t have a TA-082 hardware by clicking this link here
2.Obtain the 1.50 to 1.00 downgrader files form here . The password for the file is I_Use_It_At_My_Own_Risk.
3.Grab a 1.00 firmware dump from somewhere or from your friends. I will not provide this for you due to legal reasons and DO NOT ask for this.
4.copy the folders (__SCE__downdater100 and %__SCE__downdater100 to /PSP/GAME/)in your memory stick. Get the official Sony 1.50 update and put it under /PSP/GAME/UPDATE
5.copy the folder downdater into the root of your memory stick.
5A. Get the official Sony 1.50 update and put it under /PSP/GAME/UPDATE
6.Plug in the adaptor and make sure your battery is charged.
7.Navigate to your game icon in the PSP xmb and start the 1.50 – 1.00 app.
8.After you confirm with the X button the downgrader will initiate DO NOT REMOVE the memory stick and DO NOT shut down the PSP.
9.after the memory stick red light stops flashing the process is done manually turn off the PSP by holding the power button.
10.If everything went right you have a 1.00 PSP. To swap the X and O buttons use this program
The difference in 1.00 is theres is no KXploit method need to run games and you can run unsigned eboots. There is a higher possibility to run custom firmware since 1.00 doesn’t have that much security, and 1.00 always runs at 333mhz cpu speed which makes it faster to load stuff but, the battery gets drained faster.Another difference is some iso loaders and homebrews don't run on 1.00 since they were coded for 1.50