The following types of boot blocks are available:

    bios  BIOS boot blocks (any disk recognized by the BIOS, such as C:,
	                    Adaptec 152x, EIDE w/co-residency)
    fd    Floppy boot blocks
    wd    IDE/ESDI/MFM/RLL/ST506/etc boot blocks
    aha   ISA SCSI boot blocks (Adaptec 154x, all Buslogic)
    eaha  EISA SCSI boot blocks (Adaptec 174x)

