That was fast! Shortly after Sony releases firmware 3.90, Dark_AleX creates his custom version. This is especially important for PSP Slim users as they can get their hands on that new Skype functionality without losing homebrew capabilities.

3.80 M33 Changes:

• 3.80 -> 3.90
• March33 NO UMD: fixed (yet another) bug related with exiting with home. (infinite semaphore wait)

Changes in updater:

• The degeneration check and correction of IDS keys happens too in 3.71 now.
• Added code to download 3.90 PBP from net via wifi. Note that his code is not yet 100% stable, it may crash when selecting AP. In that case, reinit the installer.
• L+triangle has been restored as method to bypass battery. If you already have 390.PBP keep those buttons pressed until you see “Veryfing 390.PBP”. If the 390.PBP is being downloaded bia wifi, press those buttons at the end of download until you see the previous sentence.

Download below, or obtain it using the M33 Network Update if you’re on 3.80 M33.

PSP Phat users can also obtain the 1.50 kernel addon below. Check out the readme(s) for installation instructions.

Download: 3.90 M33
Download: 3.90 M33 1.50 Kernel Addon

[Source: Dark_AleX]