Comment by lin0tune

http://www.emulator101.com/logical-operations.html

   /* Example 2: turn on one LED on the control panel */    
   char * LED_pointer = (char *) 0x2089;    
   char led = *LED_pointer;    
   led = led | 0x40; //set LED controlled by bit 6    
   *LED_pointer = led;

Really?