title: How to read a value of an hard coded address in C++?
body: <p>I am looking to read the value that is located in address 302H. The purpose is to read an input from hardware (a part of a 104pc stack). When I run the following code a get this error: <code>Unhandled exception at 0x004134b9 in setOutput.exe: 0xC0000005: Access violation reading location 0x00000302.</code></p>
  
  <pre><code>#include &lt;stdlib.h&gt; 
  
  #define PORTBASE 0x302
  int _tmain(int argc, char *argv[])
  {
      int value;
      int volatile * port = (int *) PORTBASE;
      printf("port = %d\n", port);
      value = *port;
      printf("port value = %d\n", value);
  }
  </code></pre>
  
  <p>EDIT:</p>
  
  <p>I am running this under widows xp. Only Documentation I can find on the board is below<img src="https://i.stack.imgur.com/cIkA4.png" alt="enter image description here"></p>
  
  <p>EDIT:</p>
  
  <p>From your answers below, I can see that I need to write a driver for the board. Can someone point me to a resource on how to do so?</p>