Int E0  - Real/32 - "c_rawio" - Perform Raw I/o With Default Console       [O]

   CL = 06h
   DL = mode describing the operation to be performed
       FFh get console input/status
       FEh get console status
       FDh get console input (blocking)
       else output DL to the console as a character

Return: AX = returned value
       for DL = FFh, the character or 00h if none available
       for DL = FEh, 00h if no characters available, FFh if any available
       for DL = FDh, the character read from the console
       else AX = 0000h
   may destroy SI,DI???

Notes: during raw I/O, the special characters ^C, O, P, and S are not
     interpreted, but are passed through
   if the virtual console is in S mode and the owning process calls
     this function, the S state is cleared

See Also: INT E0/CL=01h,INT E0/CL=02h,INT 21/AH=06h