i am very new to this PSP scene, but have been dealing with "image" files like bin/cue etc for many moons, so please take what i am about to say w/ a grain of salt... an ISO is a straightup image of a CDROM/disk/UMD. What i heard is that back when there were only 1GB MS's, and UMD ISOs were bigger than 1GB, that someone figured out how to rip certin un-needed parts of the ISO image out... i have heard that the un-needed parts could be music or cutsceens, or just "blank" parts of the image. After they figured that out, they "recompiled", if you will, the ISOs w/out the aforementioned needless info, thus making them smaller and able to fit on a 1GB MS. Kinda like if the ISO was a picture of a building and the area around the building, someone figured out how to get rid of the non-building portions of the picture (image), making the ISO image smaller yet still large enough to hold all the necessary info to see the building. So it's lossy compression, but what is lost is needless anyway. The reason they lag is because the info left on the CSO image is not in the exact same sector of the image, so the laser has to look around on the image until it finds the info it needs. That's the jist of what i heard, please go ahead and call me a 'n00b' and correct me if i am mistaken/misinformed, as I am just as curious to know the 100% correct reasoning for making CSOs as the next 'n00b'. On another note, i think that 'n00b' is a stupid word; everyone is a 'n00b' at one point--no one was born with this knowledge, so it seems to me that people who call others 'n00bs' are just trying to look "cool" when they know good and well that they had to start learning from square one just like everyone else. Unless they are robots or aliens--don't get me started there
Sharing info is the only way the scenes will survive, so if someone has a definitive answer on this i would love to hear it--not so i could become "l33t" and call people "n00bs", but so i could help spread the word so we can all understand how it works.