The BIOS must be named "scph1001.bin". You can use any PSX BIOS you want, but you must give it that name. For example, I use the BIOS that is used in the PSOne (the redesigned PSX). It is named SCPH101.bin, but I just renamed it to SCPH1001.bin and it works fine. Also, I don't think it can be zipped. So if your BIOS is zipped try unzipping the file and see if it works then.