El Torito

Developed by IBM and Phoenix Technologies, El Torito is the standard for creating bootable CDs on IBM compatible computers. In order for an El Torito disc to work the computer must have a compatible El Torito IDE/SCSI disc drive and a compatible motherboard BIOS or SCSI BIOS.
When booting from an El Torito CD, if the disc was created using a floppy disk image, the CD will become the A: drive, the floppy drive will become the B: drive and the B: drive becomes unavailable. An El Torito disc can also be created using a hard disk drive image; when this is done, the C: drive becomes the disc drive and all other drive letters move up one.