InsaneNutter
Resident Nutter
The Prometheus v2 firmware will allow your PSP running custom 5.50 firmware to play games that require the 6.20 firmware.
Download Prometheus v2
I can confirm this works on my PSP 1000, it is supposed to work on PSP 2000's models too however I am unable to confirm this.
You will need to have 5.50 GEN-D3 on your PSP before upgrading to Prometheus v2.
To install simply copy the 5.50_Prometheus folder from the rar to your PSP\Game folder on the memory card, and then launch the updater from the games menu.
After that you will be asked to press X to install, then X to re start the PSP once the install has finished.
The end result
Games that require the 6.20 firmware should now hopefully work fine.
Download Prometheus v2
I can confirm this works on my PSP 1000, it is supposed to work on PSP 2000's models too however I am unable to confirm this.
You will need to have 5.50 GEN-D3 on your PSP before upgrading to Prometheus v2.
To install simply copy the 5.50_Prometheus folder from the rar to your PSP\Game folder on the memory card, and then launch the updater from the games menu.
After that you will be asked to press X to install, then X to re start the PSP once the install has finished.
The end result
Games that require the 6.20 firmware should now hopefully work fine.
