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  Description:  IOCTL: Read Control Data from Character
                Device Driver
 
  Reads control data from a character device driver. The length and con-
  tents of the data are specific to each device driver and do not follow
  any standard format. This function does not necessarily result in any
  input from the physical device.
 
  Input                                     Output
  ══════════════════════════════            ═══════════════════════════
  AH=44H                                    If function successful
  AL=02H                                    Carry flag=clear
  BX=handle                                 AX=bytes read
  CX=number of bytes to read                and buffer contains control
  DS:DX=segment:offset of buffer             data from driver
                                            If function unsuccessful
                                            Carry flag=set
                                            AX=error code
                                    -♦-