Hi there
My enlish is not fluent but i hope you will get a clue...
I got assignement to write program doing PC to PC communication entire in assembly. I made an effort to do this. But... it wont work.
I can't initialize port with following code:

mov dx, 02FBh
        mov al, 80h
        out dx, al
        // LSB of baud rate
        mov dx, 02F8h
        mov al, 0Ch
        out dx, al
        //MSB of boud rate
        mov dx, 02F9h
        mov al, 0h
        out dx, al
        //LCR
        mov al, 03h
        mov dx, 02FBh
        out dx, al

        //MCR
        mov al, 0h
        mov dx, 02FCh
        out dx, al

        //IER
        mov al, 01h;
        mov dx, 02F9h
        out dx, al

What am i missing here?
The funny thig is that when i start hyper terminal( two of them one on com1 other on com2) and then write code just to send a few chars and execute it terminal recive character sent. I conclude that my initialization is wrong but i dont know why. I raed dozen tutorials .... and tried everything but i didnt helped. Some help would be nice. If someone see mistake or can point me to some good tutorial it would be very helpfull.
THANKS

Any information would be very helpfull. Please point me to some text or website. Thabke:mrgreen:

the only way I've done it is to write a TSR interrupt-driven device driver under MS-DOS 6.2. See this for basics. It is definitely not a triviel program to write.

MS-Windows already contains the device drivers and is probably what the terminal program uses. I don't know how to call them from assembly, other than calling the win32 api function OpenFile(), ReadFile()n and WriteFile().

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