INT 14h,  00h (00)       Initialize Serial Port Parameters

Initializes the baud rate, parity, stop-bit, and word length
parameters for a serial port, and returns the status for the port.

On entry:      AH         00h
AL         Communications parameters (see below)
DX         Serial port number (0 - COM1, 1 - COM2, etc.)

Returns:       AX         Line and modem status (see Service 03h)

                                                                          

           Baud rate           Parity           Stop bits      Word Length
Bit:    7 6 5               4 3              2              1 0
0 0 0    110        0 0  None        0  One         1 0  7 bits
0 0 1    150        0 1  Odd         1  Two         1 1  8 bits
0 1 0    300        1 0  None
0 1 1    600        1 1  Even
1 0 0  1,200
1 0 1  2,400
1 1 0  4,800
1 1 1  9,600

See also: INT 14h, 03h

INT 14h, 00h (00) Initialize Serial Port Parameters