PSP Emulation for Newbs

Let me just say up front when it comes to being a PSP newb, I am as green as they come. So forgive me if some of these questions have been asked a few times.

I'm thinking about buying a PSP for one reason only: emulation! I could care less about the first party Sony titles. NES, SNES and Sega are where it's at baby!

Anyway, here are a few of my questions I haven't been able to find an answer to by searching the forums:

1) Is there a way to verify the Firmware version (1.0 or 1.50) before you buy the system. If not, can you downgrade the Firmware?

2) The emulators are stored on the PSP itself but what about the ROMs? Are they stored on the system itself? If so, how much room do you have to store ROMs. Can you also store and load ROMs from a external memory stick?

3) Are there some PSP games that will automatically upgrade my firmware without my permission upon inserting the disk or does it always allow you the option to deny the upgrade?

4) Do the emulators run fullscreen of the PSP?

5) Are there some ROMs that will not run on the PSP (that would normally run on a PC)?

"Any help here would be hot."

For #1 see this thread: http://www.dcemu.co.uk/vbulletin/showthread.php?t=10375. I'm not sure about the rest, because I'm still a noob, too :).

1. Yes, you can identify version 1.50 by looking near the bar code on the side. There is a number 120V and a letter after that. If its either an "A", or nothing there, its a 1.50. No you cant downgrade.

2. The emulators and roms are both stored on the memory stick. How much room, depends on how big your stick is. No you cant load roms from an external source.

3. No. You always have the option.

4. Some do, some dont.

5. As far as speed wise, yes. Also, the mame emulators dont support a large portion of the available games that the PC emu's run.