From the readme:

This is a 3.xx+ kernel app to display Tachyon, Baryon and Pommel version numbers of your PSP's motherboard. It also displays the PSP model (TA-079, TA-081, etc.) and overall PSP version based on this data.

Just copy the PSPident folder to your GAME/GAME3XX folder and run it. If you want, it will also run in the 1.50 kernel.

NOTE: If your PSP is detected as a TA-085 v2/TA-088, it one of the newest Slim revisions which cannot write to the battery serial and therefore cannot be used to create a Pandora battery!

Information about the numbers printed:

• Kernel version - internal version of the current kernel you are running the app on (could be either 1.50 or 3.xx if you're using OE/M33)
• Tachyon - this seems to be the version of the chip which contains the CPU, ME and GPU.
• Baryon - this is the version number of your PSP's Syscon (system control) chip
• Pommel - the PSP's GPIO/watchdog which handles system events and shuts down in the event of a crash
• Kirk - the PSP's main decryption/verification chip
• Spock - secondary decryption chip, only used to decrypt data from the UMD discs

Note: these are SCE names for these devices

Changelog:

0.73.2 -> 0.74

• Latest PSP models (TA-095) support
• Now you may see your g-spot... erm, g-eneration