Hidden menu works on all PS consoles!
The hidden menu discovered on the PS Vita also works on other PS consoles! I have tested it on my PSP Phat with 5.00, PSP Slim with 6.60, and PS3 Phat with 4.00! Yes the PS3! The button configuration is the same, simultaneously hold L+R+Left+Square for a couple seconds and then press and hold Start while in Settings>System Settings>System Information. What it does is it brings up info from version.txt in flash0:/vsh/etc on the PSP, the PS3 brings up more info. Are there other hidden features? Find out. Give it a try and see for yourself.