Function 440Dh /41h     Write Track on Logical Drive                 DOS 3.2+

    Writes data from a buffer to a track on the specified drive.

        Entry   AX    = 440Dh
                BX    = Drive number (0 = default, 1 = A, etc.)
                CH    = 08h (device category, must be 8)
                CL    = 41h
                DS:DX = Pointer to an RWBlock structure

        Return  AX = Error code, if CF is set
                     | 01h Invalid function
                     | 02h File not found
                     | 05h Access denied

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    The RWBlock structure contains information that specifies the
    sectors to be written to. The rwBuffer field must contain the
    address of the buffer that contains the data to write to the disk.
                                                     
    This function returns an error value of 2 (file not found) if the
    specified drive number is invalid.

    Unlike Int 26h, this function can write hidden sectors.