title: assembly 8086 carry flag - signed number how minus equals plus
body: <p>I dont understood something. This the question:</p>
  
  <pre><code>mov  al,-128d
  mov  ah,40d
  add  al,ah ;result is out of 8 bit unsigned range?
  </code></pre>
  
  <p>why carry flag dont turn on?
  it's need to be 88, 88 don't in the range of 0-255!</p>
  
  <p><strong>why the number little d in the end and not with little h? its decimal number?</strong></p>
  
  <p>why <code>-128 + 40</code> equals <code>168</code>? </p>
  
  <p>How is it possible?</p>