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  Interrupt:   21h     Function:   44h     Subfunction:   05h
 
  Title:       IOCTL: Write Control Data to Block Device Driver
 
  Description:
 
     Transfers control data from an application program directly to a
     block device driver. The length and contents of the control data
     are specific to each device driver and do not follow any standard
     format. This function does not necessarily result in any output to
     the physical device.
 
     Input                              Output
 
     AH = 44h                           If function successful
     AL = 05h                             Carry flag: clear
     BL = Drive code (0 = default,        AX = Bytes transferred
          1 = A, 2 = B,...)
     CX = Number of bytes to write      If function unsuccessful
     DS:DX = segment:offset of data       Carry flag: set
                                          AX = Error code (01h, 05h,
                                               06h,or 0Dh)
                                          See: ◄Error codes►
                                    -♦-