1. Install Custom firmware on to your psp
Sony does not consider CFW illegal however they said that it brakes your devices warranty if installed.
2. umd's to iso
One of the advantages of running PSP on a hacked firmware, or lightweight custom firmware (LCFW) to be precise, is that you can make a copy of the UMD disks you legally own as ISO files and run them using PSP’s memory stick. Though a lot of people just download the game they want we wont do that because its wrong, and illegal (=_=)... umm but yeah, i will show you a legal way that you can turn your allready owned games into ISOs.
Step one
We will mount the UMD disks using the USB connection instead of memory stick and copy the contained ISO file. To begin with, when you are on main PSP CXMB menu, press the Select button to open the PRO VHS menu. In the PRO VHS menu, navigate to USB Device (usually the third option), and you will find Memory Stick selected by default. Use PSP navigation keys to select UMD Disk and exit the VHS menu.
Now insert a UMD disk in PSP and after connecting it to your computer using a data cable, go to PSP Settings and select Initialize USB Connection. By default, PSP mounts your memory stick but thanks to PRO VHS menu, this time it will mount the UMD disk instead.
Conclusion You can now keep all your UMD’s in a safe place and play using the ISO files you legally own. People with limited storage space on memory stick.
Original Guide by: http://www.guidingtech.com
3. cool no save space and turn those iso to cso
1. CSO baby
To turn Your ISO into a CSO you will need a compressor software i suggest Yacc or UMDgen. These software's will make the game smaller by 200-300mb depending on the game, sometimes even 600mb of the game is compressed, though loading time increases a little while playing the game the quality remains the same.
Yacc
Yacc (Yet Another Cso Compressor) is preety straight forward. Here is a video on how to compress you ISOs with yacc. >>>>>>Yet another CSO compressor<<<<<<
UMDgen
UMDgen is my main ripping and compressing software so i prefer it, although a bit more complicated.
1. Open UMDgen
Ripping is a lot more complicated but can make an ISO 60% smaller if done right. If you want to play just the game and your not in it for the story and you always skip the cut scenes then why don't you just save space and rip out all the scenes from your ISO. It even works for the in game music if your the type of gamer who mutes games. For ripping you will need UMDgen.
UMDGen is software for PSP gamers who have an ISO/CSO game and want to compress the file even further in order to allow it to fit on a memory stick.
Things needed:
A computer
A CFW PSP (recommended 3.90 M33-3)
WinRAR installed on said computer
USB cable
UMDGen (http://www.psp-hacks.com/file/948)
A PSP ISO/CSO
And a memory stick
IF you already have the ISO/CSO, click on the Open tab on the top bar. Navigate to the place where your ISO/CSO is, then open it. When the ISO/CSO is opened, the screen will look like this:
In order to save your file, you may save it in the following formats:
ISO: offers the best performance, but a large file for the memory stick
CSO: slightly smaller size to significant size decrease, less performance as the PSP has to convert the game from CSO to ISO mid play
DAX: I really don't use this conversion, but it is said to be a compressing format that Dark_Alex created. It holds similar characteristics to CSO compression.
Recommendation: ISO or CSO is what I use regularly.
Just go back to the Explorer tab and drag and drop those files into the left column. Then make your adjustments if you please, then you can save it.
Explanations
Padding and Dummy files are 'useless' files that Sony and game developers use to increase the size of the ISO.
Ripping is the process of taking out/deleting files that you do not need from the ISO/CSO. Some examples that you'd want to rip are movies and sound.
(I am using Naruto Ultimate Ninja Heroes 2: the Phantom Fortress [above] as example ISO)
After you have already opened your game, go tot the left column where it has the small UMD symbol. Click on the + sign. Here some folders should appear under it. The folders you MUST see are: SYSDIR and USRDIR.
The SYSDIR has a dummy folder. The dummy folder here is the UPDATE forlder. Just right click on the dummy folder and delete it. Just the UPDATE folder, nothing else, or your game will not boot.
The USRDIR might have folders such as sound and voice. Since this game has both English and Japanese options for voice, and since I don't speak or read Japanese, I deleted the Japanese folder under voice.
You may also have an option to delete background music (bgm). Here you might see a bunch of atrac3 files. You can choose to delete them if you wish.
Movies are the popular things to rip from ISO's. Just click on the folder to display the contents in the right column so you can delete individual movies, or just delete the whole folder, your choice.
If I was not clear before, you can search for dummy files and resize them by using the 'Dummy Search' button at the top toolbar. Not all files can be made dummies, and usually only the UPDATE .BOOT will be made a dummy file.
After you had fun ripping the crap placed in the game, just simply save your game as an ISO/CSO.
Please note that not all games are as friendly as this, some games place their data in .pkg files. Example Crisis Core: Final Fantasy VII, I still have not found a uncompression program for that file extension yet. So I gave up and bought a 2 GB memory stick, and ripped the UPDATE folder...
Original guide by Dmac154
4. wanna play online
1. Xlink kai
Well what can i say Xlink Kai is almost dead and extremely hard to setup honestly you will find a few games still being played but if you wanna play a game then you will need to arrange a match a with people cause a lot of games lack players on Xlink Kai servers. If intrested then follow the link >>>>Xlink Kai PSP<<<<
2. PRO-C(Pro Online)
I love Pro client Online is simple and fast, Its basically a plug in for the PSP CFW that allows you to play online with other people using a WIFI connection. Although many games dont support Pro Online due to optimization all the popular games work well so far, I play Monster Hunter all the time with this. >>>>PRO-C(Pro Online)<<<<
5. tons and tons of psp cfw apps and themes
Well if you love minecraft then you will LOVE this on your PSP
>>>>Minecraft link<<<< For more details follow link >>>Nico-blog<<<
2. Gameboy Advanced Emulator for PSP
lost your old gameboy or did your dad get you a PSP instead of a gameboySP well here you go.
>>>Gameboy Advanced Emulator for PSP<<<
3. Nintendo 64 Emulator
Mario cart?? pokemon stadium?? play it all again, your classic Nintendo 64 games on your PSP
>>>N64<<<
4. CWcheats
CWcheats is more of a CFW plug-in but its used as an app. Don't rage quit when you can cheat, sometimes cheats is the only way to go :3.
>>>CWcheats<<<
5. Themes, themes and more themes
You can get awesome CFW themes from Google and searching but I know a site where you can get good Themes. Nicoblog is a grate place to get games and apps for you psp.
>>>Themes Nico<<<
6. These other apps from this site might intrest you, they are thousnads and thousands of apps so keep looking. >>>Homebrew Applications<<
Well thats just about it for the PSP so don't toss that PSP out of the window enjoy all the possibilities you ca have with it dont forget that Old Is Gold. Subscribe to my blog for updates, leave comments if you need help. :3 add me on steam and origins name ign is LcieKJ.