INT 13h,  0Dh (13)       Alternate Disk Reset                      fixed disk

    Resets the fixed disk controller and drives, forcing recalibration of
    the read/write heads. This service can be performed on fixed disks
    only.

       On entry:      AH         0Dh
                      DL         Drive number (Bit 7 must be set)

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

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       Notes:         See Service 00h for a more generalized version of
                      this service.

                      A fixed disk reset is only executed if the value in
                      DL is less than or equal to the last fixed disk on
                      the system. That is, the lower 7 bits of DL should
                      be less than or equal to the number of fixed disks.

                      For the AT, XT-286, and PC Convertible, the BIOS
                      executes INT 15h, Service 90h (Device Busy), for the
                      diskette (Type = 01h) and the fixed disk (Type =
                      00h) prior to waiting for the interrupt. INT 15h,
                      Service 91h (Interrupt Complete), is executed upon
                      completion.