INT 13 - Future Domain SCSI BIOS - GET SCSI CONTROLLER INFORMATION
        AH = 18h
        DL = hard drive ID
Return: CF set on error
            AH = status code (see AH=01h)
        CF clear if successful
            AX = 4321h (magic number)
            CX = controller family code
                0203h TMC-1650/1660/1670/1680 (ROM 2.0)
                        BH = number of exclusively ROM-controlled SCSI devices
                        BL = canonical SCSI device number for specified drive
                040Ah TMC-820/830/840/850/860/870/875/880/885 (ROM <= 6.0A)
                        BH = number of exclusively ROM-controlled SCSI devices
                        BL = canonical SCSI device number for specified drive
                050Dh TMC-840/841/880/881 (ROM 5.2D)
                        BH = number of exclusively ROM-controlled SCSI devices
                        BL = canonical SCSI device number for specified drive
                0700h TMC-830/850/860/875/885 (ROM 7.0)
                        DH = number of exclusively ROM-controlled SCSI devices
                        DL = canonical SCSI device number for specified drive
Note:   also sets an internal flag (non-resettable) which prevents some
          controller messages from being displayed, allows writes to
          removable devices (use caution!), and enables the INT 13 interface
          for more than one drive (i.e. DL >= 81h) in at least some ROM
          versions
SeeAlso: AH=1Bh"SCSI"