Interrupt 14h	Initialize and Access Serial Port For Int 14
(0:0050h)
 
Int Function	Description
---------==-    ---------------------------------------------------------------
Int\14f\00	Initialize And Access Serial Communications Port
Int\14f\01	Send Character in AL to Comm Port DX (0 or 1)
Int\14f\02	Wait For A Character From Comm Port DX
Int\14f\03	Fetch the Status of Comm Port DX (0 or 1)
Int\14f\04	Extended Initialize				(PC Convertible)
Int\14f\05	Extended Communication Port Control		(PS/2)
 All routines have AH=function number and DX=RS232 card number (0 based).
 AL=character to send or received character on exit, unless otherwise noted.
 
        serial status byte:
        bits    0 delta clear to send 
                1 delta data set ready 
                2 trailing edge ring detector 
                3 delta receive line signal detect 
                4 clear to send 
                5 data set ready 
                6 ring indicator 
                7 receive line signal detect 
 
        line status byte: 
        bits    0 data ready 
                1 overrun error 
                2 parity error 
                3 framing error 
                4 break detect 
                5 transmit holding register empty 
                6 transmit shift register empty 
                7 time out  note: if bit 7 set then other bits are invalid 
 
        port parameter byte
        Byte BBBPPSLL
             BBB       baud rate:   110,150,300,600,1200,2400,4800,9600
                PP     parity:      01 = odd, 11 = even
                  S    stop bits:   0 = 1, 1 = 2
                   LL  word length: 10 = 7-bits, 11 = 8-bits
 
see also NS\16550AF  National Semiconductor 16550AF Advantages & Detection


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