INT 13h,  06h (6)        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.

       On 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)

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

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       Notes:         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.