INT 14 - Egberto Willies COMM-DRV - EXTENDED INITIALIZATION
AH = 81h
BX:DI -> port control block
Return: ???

Format of port control block:
Offset  Type    Description
00h    WORD    port IO address
02h    WORD    port IRQ
04h    WORD    baud rate
06h    WORD    parity
08h    WORD    data bits
0Ah    WORD    stop bits
0Ch    WORD    break status
0000h off
0Eh    WORD    flow control protocol
10h    BYTE    input block
11h    BYTE    output block
12h    WORD    low threshold
14h    WORD    high threshold
16h    WORD    segment of buffer
18h    WORD    offset of buffer
1Ah    WORD    input buffer length
1Ch    WORD    output buffer length
1Eh    BYTE    auxiliary address
1Fh    BYTE    spare
20h  4 WORDs   spares

See also: 1400

1481 - Egberto Willies COMM-DRV - EXTENDED INITIALIZATION