Is downgrade possible?

I just recently bought the slim starwars psp. I accidentally upgraded to fw 3.80. Can it be downgraded so that I can play Nes games and ps games or is it not possible yet?

Yea, you just need to use 1 of the 2 tutorials. But in order to use these tutorials you need the use of another psp with custom firmware on it. Since the installers are homebrew programs, you need a psp with custom firmware to run it.

*Despertar Cementario
*U.M.P.S, Be sure to use the tutorial for SLIM PSPS and not phat psps.

When you usethese tutorials, they will put your PSP on 3.71 M33 Custom Firmware.
NOTE: The Pandora's Battery and Magic Memory Stick will not work for your psp since they downgrade your psp to 1.50 and the slim isn't compatible to the 1.50 firmware, so it won't work.

I just read a help post about hard modding a battery to make it a switchable pandora battery for the slim. Is this legit and it if is would it actually eliminate the need of a phat psp with cfw to downgrade my slim which is currently running 3.80?

Das7771, i can tell you from experiance that hardmodding the slim battery *WORKS* and use TOTALNewbie easy installer. That way u Dont need a phat psp or a psp with cfw.

Ok, I have decided to go ahead and hard mod my slim psp battery by removing the pin on the chip. My only problem is I have found a couple of links that don't seen to be removing the same pin. I want to make sure I do it right the first time. Can some one please send me a link with the turtorial or at least a clear picture of which pin to remove.

http://pspbrew.com/forum/viewtopic.php?t=9644

well I removed the pin. So do I now use total newbie installer?

-edit-

LMFAO...I spent so much damn time reading a bunch of post I acutally confused my self and pulled the pin off a slim psp battery instead of soldering a jumper wire...Not too bright...Luckily I was able to push the pin back in place and the battery works fine...Im gonna get some sleep and maybe my dumb @$$ can do it right tomorrow...Thanks for all of the help I really appreciate it.