C program for serial communication between 2 pcs using null modem connection using RS232

//C program for serial communication between 2 pcs using null modem connection using RS232

#include <bios.h>
#include <conio.h>
#define COM1       0
#define DATA_READY 0x100
#define SETTINGS ( 0x80 | 0x08 | 0x00 | 0x03)
int main(void)
{
   int in, out, status;
   bioscom(0, SETTINGS, COM1); /*initialize the port*/
   cprintf("Data sent to you: \n ");
   while (1)
   {
      status = bioscom(3, 0, COM1); /*wait until get a data*/
      if (status & DATA_READY)
           if ((out = bioscom(2, 0, COM1) & 0x7F) != 0)  /*input a data*/
              putch(out);
           if (kbhit())
           {
              if ((in = getch()) == 27)   /* ASCII of Esc*/
                 break;
              bioscom(1, in, COM1);   /*output a data*/
           }
   }
   return 0;
}