I have a device which should be written via RS232 port.
The board only has the DTR, TD, RTS and GND connected. We
want to write some binary data to the board. We want
individually control the DTR,RTS bit(might TD bit?) to
control our board. Can exsisting serial driver(COM1,COM2,
etc.) do this?

If I have to write my serial driver. How to decide which
I/O port my serial port used (0x2F7-0x2FF or 0x3F7-3FF)?

Thanks.