Parallel Port Problems

[legsmacgee]

Hello,

I have written the following program in MS Visual C++ running on windows XP. It is supposed to set all the data lines of my parallel port to "high" when password 2006 is entered, and "low" when 9999 is entered. I am using UserPort to get around the port access restrictions of XP. I have a multimeter hooked up to pins 2 and 18 on my computer, and I'm reading 4.2 volts no matter what I enter. Here is the code:

#include "stdafx.h"

#include "conio.h"

#include "stdio.h"

#include "string.h"

#include "stdlib.h" 

#include <iostream>

using namespace std;

int main ()

{

int i;


do{

cout << "Please enter password: ";

cin >> i;

if (i == 2006) {

cout << "\n Password accepted \n Unlocking door... \n";


_outp(0x378, 255); 

cout << " Door has been unlocked... \n \n \n";

}

else if(i == 9999){

cout << "   System shutting down... \n\n\n";

_outp(0x378, 0); 

}

else {

cout << "Entry denied \n\n";

}

}while (i != 6606);

return 0;

}

Is this code simply flawed, or is there some other issue here?

Thanks,

James

[Danny]

This code is designed for POSIX systems, and XP somehow supports it as a non-native extension or API. Vista is more secure and doesn't allow you to access hardware ports like this. You need to use a special library for that which essentially wraps low level hardware access with a higher level API (which is more secure and restricted).