title: Algorithm to check if byte is 0x00 or 0xFF
body: <p>Is there a logical equivalent to:</p>
  
  <p><strike><code>if(byte != 0x00 || byte != 0xFF)</code> </strike></p>
  
  <pre><code>if(byte != 0x00 &amp;&amp; byte != 0xFF)
  </code></pre>
  
  <p>I'm at my program memory limit and can use every optimalisation :)</p>
  
  <p>To explain with words, can you check with a logic function if all bits are same (so all 0 or all 1)?</p>
  
  <p>Thanks!</p>