INT 14h,  00h    Set baud rate

Entry: AL Baud rate code

DX Port number

Exit: AX Port status (see function 03h)

This works the same as the equivalent IBM PC BIOS call, except that it
ONLY selects a baud rate. This is passed in the high order 3 bits of AL
as follows:

010 = 300 baud
011 = 600 ''
100 = 1200 ''
101 = 2400 ''
110 = 4800 ''
111 = 9600 ''
000 = 19200 '' (Replaces old 110 baud mask)
001 = 38400 '' (Replaces old 150 baud mask)

The low order 5 bits can be implemented or not by the FOSSIL, but in all
cases, if the low order bits of AL are 00011, the result should be that
the communications device should be set to eight data bits, one stop bit
and no parity. This setting is a MINIMUM REQUIREMENT of Fido, Opus and
SEAdog. For purposes of completeness, here are the IBM PC "compatible"
bit settings:

Bits 4-3 define parity: 0 0 no parity
1 0 no parity
0 1 odd parity
1 1 even parity

Bit 2 defines stop bits: 0 1 stop bit;
1 1.5 bits for 5-bit char;
2 for others

Bits 1-0 character length: 0 0 5 bits
0 1 6 bits
1 0 7 bits
1 1 8 bits