Well I bought a "1.5" off eBay, but when it came it was 2.0 , they provided DevHook 0.45, about 20 ISOs and a few 1GB cards. Basically, I'm a bit clueless and would like to know what is the safest and easiest way to get the ISOs up and running?
I know 3.40OE-A gives you the ability to play ".cso" and ".iso" files without a UMD. If you downgrade to 1.50 and then upgrade to 3.40OE-A, you're pretty much set. I believe all you need is the downgrader to downgrade 2.00, no UMD trick reqiured. Once you've dont that, and have 3.40OE-A, boot up in Recovery Mode (boot holding R-Trigger) and go to Configuration->No-UMD [Enabled]. By default it is disable and for good reason. If the PSP has to load a game without a UMD, it has to load the isocache manually, which takes a while. Basically, games will run MUCH faster with less lag with a UMD than without.
