PSP:Chronoswitch

Chronoswitch is a homebrew PSP utility that allows a console to freely upgrade and downgrade official PSP firmware. It is mainly useful for reverting a cIPL or Infinity console with PRO/ME CFW to OFW for installing cIPL ARK-4, or downgrading fron 6.61 to 6.60.

The following guide has instructions courtacy of the pspunk.

Chronoswitch

Information
Author	DaveeFTW (Original) The Zett (v7.1 and v7.2) krazynez (v7.3 onwards)
Type	PSP Firmware Downgrader/Reinstaller
Version	v7.4
License	Open
Links
Website	N/A
Source	https://github.com/krazynez/Chronoswitch/
Download(s)	https://github.com/krazynez/Chronoswitch/releases/latest

Prequsites

• Having at least 80% battery life
• Fully secured battery that will not fall out
• Ideally, a charger plugged into the system
• A 6.20 or newer firmware PUP. Anything older instead requires a compatible PSP with a JigKick & Magic Memory Stick.

Usage

1. Download the latest build of Chronoswitch.
2. Get the desired firmware update for your PSP. They can be reached from the following places:
   • Sony CDN
   • Darthsternie's archive
   • Midnightchannel archive
3. Transfer Chronoswitch's EBOOT.PBP file in the file path of ms0:/PSP/GAME/Chronoswitch/EBOOT.PBP on the console's memory stick, with ms0:/ being the root directory.
   • If using the PSP Go's internal storage, ms0:/ instead becomes ef0:/.
4. Transfer the firmware update file to ms0:/PSP/GAME/UPDATE/EBOOT.PBP on the console's memory stick, with ms0:/ being the root directory.
   • If using the PSP Go's internal storage, ms0:/ instead becomes ef0:/
   • If your update file is named something like 6.61.PBP, then rename it to EBOOT.PBP
5. Launch the Chronoswitch application and follow the on-screen instructions. Once completed, the PSP will restart and will now be on the official firmware version that was chosen.