Int 14 Fn 81  - Egberto Willies Comm-drv - Extended Initialization         [S]

   AH = 81h
   BX:DI -> port control block

Return: ???

See Also: AH=00h

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