hi!
i have one c code that i have persnolly tried and it works it uses
com1 port to communicate
the code as below
/* Stop and Wait Protocol ( Flow Control ) */
#include<stdio.h>
#include<bios.h>
#include<conio.h>
#define COM1 0
#define SETTINGS 0x82
#define DTR 0x100
void main()
{
int ch,status,i=0,true=1;
char msg[100],ack,rec;
clrscr();
bioscom(0,SETTINGS,COM1);
printf("\n 1.Transmit\n 2.Receive");
printf("\n\n Enter the operation code : ");
scanf("%d",&ch);
switch(ch)
{
case 1 : printf("\n Enter the Message \n ");
scanf("%s",&msg);
while(msg[i]!='\0')
{
bioscom(1,msg[i],COM1);
printf("\n%c",msg[i]);
do
{
while(1)
{
status=bioscom(3,0,COM1);
if(status & DTR)
{
ack=bioscom(2,0,COM1) & 0x7F;
if(ack=='0')
{
bioscom(1,msg[i],COM1);
printf("\n%c - retransmitted ",msg[i]);
}
break;
}
}
}while(ack!='1');
i++;
}
break;
case 2 : printf("\n Receiver \t Press Escape to quit\n\n");
do
{
status=bioscom(3,0,COM1);
if(status & DTR)
{
rec=bioscom(2,0,COM1);
printf("\n%c -- Enter ACK(1 for +ve, 0 for -ve) :",rec);
ack=getche();
bioscom(1,ack,COM1);
}
if(kbhit())
if(getch()=='\x1b')
true=0;
}while(true);
break;
default : printf("\n Invalid Selection");
}
}
if u have any doubts u can contact me at bipinramesh@gmail.com |