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  Interrupt:   14h     Function:   02h
 
  Title:       Read Character from Communications Port
 
  See also:    Auxiliary Input
 
  Description:                                          [PC] [AT] [PS/2]
 
 
     Reads a character from the specific serial communications port,
     and also returns the port's status.
 
     Input                               Output
 
     AH = 02h                            If function successful
     DX = Communications port              AH bit 7 = 0
          number (0 = COM1,                AH bits 0-6 = Status
          1 = COM2,...)
                                           Bits   Significance (if set)
 
                                           4      Break detected
                                           3      Framing error detected
                                           2      Parity error detected
                                           1      Overrun error detected
 
                                           AL = Character
 
                                         If function unsuccessful
                                         (timed-out)
                                           AH bit 7 = 1
                                    -♦-