[XT] [AT]
Expects: AH    0cH
CX    track (cylinder) number; see below
DL    drive: 80H-81H=hard disk 0-1
DH    head number
                                                                  
Returns: AH    BIOS disk error code if CF is set to CY
                                                                  
Info: This moves the read/write head directly to a specified track.

CX Bits 6-7 of CL are the high two bits of the 10-bit value whose
low 8 bits are in CH.  See INT 13H 02H for details.

Notes:   It is not necessary to use this seek function before any other
functions (such as read, write, format or verify).

  This is used mainly in benchmark tests and diagnostic programs.

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INT 13H 0cH: Seek Cylinder