I killed my psp for now...

I upgraded to 2.7, I know now there working on the 2.5 and 6 now. Think its possible for 2.7? Also there's one thing I really want to know, how do these people make emulators and roms, and how do they know how to crack a psp how do they find these things and how do they read all that data, and what files do what? I would really like to know how they got started and what they do, cause I would love to try to take a hand into it also.