----------1400-------------------------------
INT 14 - SERIAL - INITIALIZE PORT
         AH = 00h
         AL = port parameters
         bits 7 - 6 - 5   4 - 3   2     1 - 0
              BAUD RATE   PARITY  STOP  WORD
              BITS LENGTH
              000   110   00 none 0: 1  00: 5
              001   150   01 odd  1: 2  01: 6
              010   300   11 even       10: 7
              011   600                 11: 8
              100  1200
              101  2400
              110  4800
              111  9600
         DX = port number
Return:  AX = port status
----------1401-------------------------------
INT 14 - SERIAL - WRITE CHARACTER TO PORT
         AH = 01h
         AL = character to write
         DX = port number
Return:  AH = line status
----------1402-------------------------------
INT 14 - SERIAL - READ CHARACTER FROM PORT
         AH = 02h
         DX = port number
Return:  AH = line status
         AL = received character
----------1403-------------------------------
INT 14 - SERIAL - GET PORT STATUS
         AH = 03h
         DX = port number
Return:  AX = port status
              AH = line status
              bits 7 - 0
                 7: timeout
                 6: transmit shift register empty
                 5: transmit holding register empty
                 4: break detected
                 3: framing error
                 2: parity error
                 1: overrun error
                 0: receive data ready
              AL = modem status
              bits 7 - 0
                 7: carrier detect
                 6: ring indicator
                 5: data set ready
                 4: clear to send
                 3: delta carrier detect
                 2: trailing edge of ring indicator
                 1: delta data set ready
                 0: delta clear to send
---------------------------------------------