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Int 13h, 06h            Format Track and Set Bad Sector Flags      fixed disk

    Initializes each sector on a specified cylinder with sector
    address and size information; also marks the sectors on the track
    as unusable (bad) by setting the bad sector flag in the ID fields.
    Only XTs may use this service.

        Entry   AH = 06h
                AL = Interleave value
                CH = Cylinder number (10-bit value; upper 2 bits in CL)
                DH = Head number
                DL = Drive number (Bit 7 must be set)

        Return  AH = Status of operation (See Service 01h)
                CF   Set if error, cleared otherwise

    ------------------------------------------------------------------

    Note
    This service will destroy all previous contents of the disk.

    The cylinder number is a ten-bit quantity (0 through 1023). Its
    most significant two bits are in bits 7 and 6 of CL; the remaining
    eight bits are in CH.

    If an error is encountered, use Service 0h to reset the drive and
    retry the operation.