Developed by IBM and Phoenix Technologies, El Torito is the standard for creating bootable CDs on IBM compatible computers. 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 becomes the A: drive and the floppy becomes the B: drive. An El Torito disc can also be created using a hard drive image. When this is done, the C: drive becomes the disc drive and all other drive letters assignments are advanced one letter.