How to Program the COM Port

[aryajur]

I need to program the COM port to read and write data from it. How can I do that in VC++. I tried the following program but it gives an exception when it is executed:

/* This program is used to pull data from the serial port */

#include <dos.h>
#include <stdio.h>
#include <conio.h>

#define PORT1 0x3F8 /* Defines Serial Port Base Address (COM1 */

void main(void){
unsigned char c = 0;
unsigned char chrctr = 0;
/*int exit = 1; */

_outp(PORT1 + 1, 0); /* Turn off interrupts */

/* PORT1 Communication Settings */

_outp(PORT1 + 3, 0x80); /* Set DLAB ON */
_outp(PORT1 + 0, 0x0C); /* Set the baud rate to 9600 */

_outp(PORT1 + 1, 0x00); /* Set Baud - Divisor latch HIGH */
_outp(PORT1 + 3, 0x03); /* 8 bits, no parity, 1 stop */
_outp(PORT1 + 2, 0xC7); /* FIFO Control Register */
_outp(PORT1 + 4, 0x0B); /* Turn on DTR, RTS, and OUT2) */

printf("Waiting on transmission from source.\nPress ESC to quit.\n");

while(chrctr != 27){ /* Execute the loop if ESC has been hit */
c = _inp(PORT1 + 5);
if (c & 0x01){
chrctr = _inp(PORT1);
printf("%d",chrctr);
}
if (kbhit()){
chrctr = getch();
_outp(PORT1, chrctr);
}
}
}


Any suggestions or tips are welcome.

 

[Salem]

The way you get access to the serial port in win32 is by using the CreateFile API call
Look for "Communications Resources"

--