register 
      will set the O flag (overflow). If the I flag is clear (not set) interrupts 
      will be ignored.</td>
  </tr>
  <tr valign="top"> 
    <td><strong>Stack</strong></td>
    <td>An area of memory used for temporary storage according to the LIFO rule. 
      Last in First out. The stack is used to save register contents for later 
      restoration, pass parameters into procedures and return results, reverse 
      the order in which data is stored, save addresses so procedures can r