PQ>Can someone tell me, or suggest any document, about
PQ>manipulation the serial chip in assembler. I haven't got
PQ>a clue.
PQ>I looked at Ralph Brown's interupt list but I didn't find it
PQ>helpful.
PQ>    How do I set up a serial port?
(Please note all my information comes from "PC Interrupts" by Ralf Brown & 
im
Kyle)
int 14h function 00h : Initialize Port
Registers at call:
AH = 00h
AL = port parameters:
  bit # 76543210
        ||||||||
        ||||||++- data bits (00 = 5, 01 = 6, 10 = 7, 11 = 8)
        |||||+--- stop bits (set = 2, clear = 1)
        |||++---- parity (01 = odd, 11 = even, other = none)
        +++------ data rate (110, 150, 300, 600, 1200, 2400, 4800, 9600 bps)
DX = port number (00-03h)
Returns:
AH = line status
AL = modem status
PQ>    How do I access it?
int 14h function 01h : Write character to port
Registers at call:
AH = 01h
AL = character to write
DX = port number
Returns:
AH bit 7 is an error flag, bits 6-0 are the port status
int 14h function 02h : Read character from port
Registers at call:
AH = 02h
AL = 00h
DX = port number
Returns:
AH = line status
AL = recieved character
PQ>    How do I communicate with my modem with
PQ>        command codes and such like?
Basically just send them as sequences of characters, follow by a carriage
return.
((Cloud))
 * OLX 2.2 * When you're at the end of your rope...tie a knot and hold
--- PCBoard (R) v15.3/M 10
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