Torch has updated his app for the PSP:

Hold+ is the ultimate companion to the PSP's music player. It adds useful features and gives you TWICE the battery life when used properly.

It does the following when the Hold switch is enabled:
* Switches off the LCD screen and backlight.
* Underclocks the CPU to 60MHz
* Fixes malfunctioning Hold switch
* The original screen brightness and clock speed are restored only when the Hold switch is released fully to the power off position
* Prevents the PSP from going into suspend mode if you accidently push the power switch too far when turning off Hold mode.
* Turns off LEDs in hold mode.
* While in hold mode, allows the use of Left, Right, LTrigger, RTrigger, Volume and Start buttons, if you hold the Select button first. Useful to skip songs, pause etc.

Additional Features:
* Enables the 5th brightness level on PSP Slim.
* Increases the vertical scrolling speed of Music player by around 50% (scroll 300 songs in 10 seconds).

Usage:
Turn on the Hold switch to automatically disable the display and underclock the CPU. Release the Hold switch fully to the power off position to return the CPU to normal speed and enable the display.

If you push the ANALOG UP button when turning on the Hold switch, it will only lock the keypad like normal hold mode. The display and CPU speed will not be changed, so that you can watch videos etc. with the keypad locked. Release the Hold switch fully to the power off position to unlock the keypad.

While the PSP is in hold mode, if you first hold down the Select button, you can use the following buttons: Left, Right, LTrigger, RTrigger, Vol+, Vol-, Start.

Installation:
You can install it in the seplugins folder, and make an entry in VSH.txt. Thus it will be active in the XMB. Its also possible to use it in games by adding it to GAME.txt, but some games may crash etc., if the CPU is underclocked to such a low value.

Optionally, its also possible to install it in your PSP's flash0 so that it will work without a Memory Stick. For this you can use FreePlay's "NewBTCFNedit" and enable it for VSH mode in the all the PSPBT?NF.bin files. Add it before vshmain.prx.

Advanced:
If you want to change the clock speed to your own values, you can use a hex editor to change them. The offsets in the file for v4.0 are
0x1154 - CPU
0x1158 - Bus (Should be half the CPU speed or less)

The values should be entered in hexadecimal. The default value for CPU is 3C (60 MHz in decimal) and the default value for Bus is 1E (30 MHz in decimal).

Note that simply using any arbitrary value will not work. You will have to test and see which values for CPU and Bus speed work.

Credits:
Thanks to adrahil for helping with preventing the suspend mode.

Thanks to Booster for the SysCon Hook sample, based on which Hold+ v3.0 was updated.


Quote:
Originally Posted by Changelog
Changelog v4.0
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This is a fix for people with broken Hold switches that keep randomly switching on and off while in Hold mode.

Now when the Hold switch is enabled, the PSP remains in hold mode permanently until the switch is fully pushed to the power off position. This will prevent a malfunctioning Hold switch from randomly interfering.

Removed Display Off mode (hold ANALOG UP while releasing Hold) since holding Select is sufficient for most users.

http://sites.google.com/site/torchddl/hold

For more information and downloads, click here!