PSP Homebrew developer Mediumgauge has released PSP Filer version 4.0, along with a test release for kernel 3.xx, which can read and rip from the UMD device.

Like the previous update, the developer has added some new features to the file organizer app. Here are the developer's notes for version PSP Filer v4.00:

General:

* Added a feature to modify CPU speed. (Though UMD ripping feature always runs in 333MHz.)
* Fixed a bug some kind of mp3 files that had LAME tags could not be played.

Filer:

* Added a feature to access ISO archive file. (Those are read-only, and cannot be marked and sorted).

And Here are the developer's notes for PSP Filer v4.00 for kernel 3.xx:

This version cannot do the following features:

* USB device.
* Flash memory maintenance.
* Writing files into flash0/flash1.
* Showing flash device information.

Users are encouraged to pore over the readme file before using the app. The readme file contains the controls for the app as well as tips on how to use it. The readme is once more available in several languages.