PSPdisp gives you an additional monitor with a 960×544 resolution (four times the area of the PSP display). There are four components working together, on Windows a display driver, an usb driver and the interface application which captures the screen, compresses it and sends it over USB to the PSP. On the PSP side there is an application that decompresses the frames and displays them. All settings are adjustable from the Windows side, the PSP really only acts as a passive display.

Changes:

New features:
– SideShow driver for Vista and Windows 7
– speed improvements / CPU load reduction
– CPU load reduction (down to 0 % without screen changes) when using the PSPdisp display driver
– rotation is now performed on the PSP, no increase in CPU load on the PC
– quality and delay settings now customizable through the UI
– completely revamped Wlan mode (switched server to the PC, can now recover from a lost connection etc.)
– added option to disable display streaming (only transmitting controls)
– new option to always switch the PSP display to the screen containing the mouse cursor
– new control file command to display an onscreen keyboard for entering text on the PSP
– new control file command to display the PSPdisp menu at the current mouse position
– added support for the assignment of key combinations to PSP buttons (e.g. ALT+F4 can be mapped to one button)
– various settings regarding PSP power saving in USB mode (turning off screen, reducing clock speed, etc. after a user defined idle timeout)
– PSP clockspeed can be configured for Wireless LAN mode (default, 111, 222, 333 Mhz)
– all user defined files (configuration data and control files) now stored in the application data path
– experimental audio streaming

Bug fixes:
– case of analog stick movements not being registered
– the two longest delay settings are now clickable
– “grab transparent windows” now actually works (only for 480×272 viewport)

Known issues:
– there are cases where the PSP waits for a Wlan timeout infinitly, making it seem to hang without any message (always fixed by restarting the PSP game, often fixed by turning the Wlan switch off and on again)
– audio will stutter if data cannot be transmitted fast enough either because of the network conditions or low PC specs
– some applications issue drawing commands without apparent screen changes, in that case there is no CPU load reduction available when using the PSPdisp display driver

http://forums.qj.net/psp-development-forum/154415-pspdisp-v0-3-a.html