I sawr a bootdisk ISO once from a yaroze system (PSX development version)
It did not work when I tried it. It boots, says "insert gane" but no workee.
 
Supposedly they patched the bootdisk to work on games although it was designed to run only unsigned games (stuff you program yourself) not designed to play games that ARE signed but are missing the oroper copy protection on the disk itself.
 
You may wanna check out www.epsxe.com
this emulator will play psx bakcups on a PC and runs very well with most games. It can even load and play iso files.

boot disk work once in a blue moon - you need a mod chip - also, do not buy one of those USB mod chips - they work even less then the boot disks do.

assuming your talking about playstation 1 you can use any real game a boot disc. use nail clippers or the likes and prop the lid open. start the original disc and when the black scea screen appears and the disc seems to slow down pop in the backup and play on.