This is one of those emulators you need to check back in 5 years, or wait on one of the other 2 PSP emulators to get developed faster, whatever happens first. There are forums for JPCSP for compatibility, and apparently certain versions of the program work better with certain games. I'd say to stay away from this one until more development occurs. PROS Its the only PSP emulator that is capable of playing a few, but very old PSP games at 100% speed. It uses Java 6 (6.21 or latest version, for most versions of the program), and the emulator itself takes up little installation space. CONS Outside of a few playable games, the emulator has no joystick support, meaning you need to use XPADDER, to go from joystick to keyboard, so you can use your joystick buttons with JPCSP. The game does not boot encrypted games, and the only way to decrypt a game, is with a real psp, which isn't a problem, as the only likely users of the program are hardcore PSP OWNERS LMAO. All emulated games do not play sounds, and the emulator supports few native psp sound formats. Meaning all games require you to "DECODE THE AUDIO FILES" then put them back into the game image. A lot of excess work for poor quality sounds and choppy video and so forth. DECRYPTING A GAME Decrypting a game is actually very easy google Iso_Tool 1.74 (its at 1.75 version now), put the game in your "ISO" folder, and the program in your "GAME" folder. Run the option to decrypt your rom, and your finished. Or for stubborn games like Starwars Battlefront Elite, you need to use edecrypt.1.4.0.tool-rev - by first extracting the eboot.bin file, then patching it and replacing the file. NOTE* you do not need to extract the eboot.bin file and replace it with Iso_tool 1.74 it does it automatically, and it maintains the lba (the lba table addresses are ignored anyway for a large portion of games). You can extract the eboot.bin from your game if your not using Iso_tool, with either umdgen-4 or WQSG_UMD_R31. I recommend WQSG_UMD_R31, because it maintains the lba table, so you don't have to worry about miss-identified files, when retroducing the eboot.bin. If you are using umdgen-4 to do this, you need to first "export" your "filelist", then add your new eboot.bin file then "import" your filelist. DO GAMES WITH PROMETHEUS PATCH APPLIED WORK WITH JPCSP?? As you know if your are using Dark Alex firmware 5.00 m33-6 cfw, (prometheus games don't work with older 3.90 m33-3 firmware). The newer games made for 6.x firmware will not work on your psp, therefore, you have to apply the DECRYPT EBOOT.BIN, VERSION PATCH, AND PROMETHEUS PATCH from Iso_Tool 1.74 to your game, and it the newer games will work, and you can avoid the buggy prometheus line of firmwares. You can easily remove the Prometheus Patch from a game to get your game to work with the JPCSP emulator This will also help your game work with prometheus firmware, as some prometheus patched games don't work on prometheus firmware (duh the patch game avoids the use of the buggy prometheus firmware line). To remove the patch this is what you will have to do. 1. Make sure the game is in the .ISO format 2. Remove the "prometheus.prx" file from the .ISO, and delete the "eboot.bin" file, make sure you rename the "eboot.old" file in the .ISO to "eboot.bin", then rebuild the image (duh using the "SAVE AS" option or "SAVE" option). Thats all, JPCSP ignores the "VERSION PATCH" option given in Iso_Tool 1.74, which is only used to help games play that are running the 5.x m33 firmware by Dark Alex. (5.00 m33-6 Dark Alex firmware, the best, enjoy your retirement Dark Alex we miss you). What have I personally tested 1. I own a Phat PSP, I used to own a SLIM PSP also, but I sold it, because homebrew support wasn't implemented in the firmware for it at the original time i purchased it. 2. I own a lot of UMD games, and when you are testing firmware and game dumps and emulator versions you need to own the real game, to avoid bad dumps, and false information. 3. I helped to correct a few of the moderators at the official JPCSP forum, about the prometheus patch usage, and removal. As JPCSP doesn't support prometheus patched games, but it has nothing to do with piracy and it is easily removed. That is you can dump a newer game on older 5.00 m33-6 firmware, but it won't boot without being patched with Iso_Tool 1.74. 4. For the few games JPCSP does support at 100% emulation, it is worth it for the extra work to decode the audio files and rebuild the .ISO, etc. But because the emulator is in its beta stages, i don't recommend it, but I am experienced with it. The best thing for you to do is to buy a psp, and enjoy your store bought games. Yes back in the day I dumped all my UMDs to memory card because I was worried about my UMD drive buring out, and by the way my UMD drive still works on my PHAT PSP, which i only use it to dump the games i own. WHAT GAMES WORK WITH PROMETHEUS PATCH? I attached an EXCEL list of all the games that need the PROMETHEUS PATCH for 5.00 m33-6 firmware below, and for some games that need the prometheus patch on prometheus firmware, its easy to remove the prometheus patch if your UMD DUMP didn't work after you patched it for your firmware (only when using prometheus firmware). Note if your game is made in 2010 and not on the list you most likely need to use a prometheus patch via Iso_tool 1.74 (DECRYPT, VERSION PATCH, PROMETHEUS PATCH .6 - SAY NO TO APPLY OLD VERSION .5 - Kingdom Hearts needs the .5 patch only from my own experience). NOTE FROM THE POSTER Stick with your PSP for now, there are other psp emulators in development, and for the record JPCSP used to be a windows build, before it switched to JAVA. I think that was a bad decision, because the windows environment is more flexible then the java environment for programming, in my opinion. Tough luck there... Lazy Patch = "VERSION PATCH" in Iso_Tool 1.74 in the list below (as stated above, DECRYPT, VERSION PATCH, and PROMETHEUS PATCH .6 - by saying no to patch old version .5 for all games on the list unless otherwise states, all the newer 2010 psp games) *All references on the list to "internet game dumps" are done so for example only, I do not condone piracy, and I do not encourage piracy, always buy your UMD's to dump them like I do.