Int 13h, 19h            Park Heads                                       PS/2

    Parks disk heads. You should do this before moving a drive.

        Entry   DL = Drive ID number (bit 7 = 1 for hard disks. 0 origin)

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

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    This service parks the heads of PS/2 disk drives. You should do
    this before moving a drive. Place the number of the disk to park
    in DL (0 origin), and set bit 7 of DL to 1 for hard disks.

    On return, AH holds the status code (see Service 01h for the
    meaning of the codes). If the carry flag is set, the operation
    failed.