Put your PSX game on your Sony PSP. Plug your PSP into your PC or Mac computer via the USB cable, and navigate to the /PSP/GAME directory on the Memory Stick Pro Duo card. Put your newly created PSX games directory with your new EBOOT.PBP file there along with a copy of your PlayStation 1 game.
PSX on PSP torrents are PS1 downloads with PlayStation 1 games that can be played / emulated on PSP with Sony made emulator. They used the Connectix PC and Mac emulator that they have bought some years ago to make this Playstation1 emulators for PSP.