Even though you figured it out, i believe there is a ps1 to psp (eboot) converter out there that is literally derived from sonys actual ps1 to psp converter, sorry i cant link you, but it shouldnt be hard to find. It works pretty brilliantly. For your reference i have used it to convert the entire Final Fantasy 9 (4 isos) to launchable (signed) psp eboots. qj.net is a great site for psp modding.