What's so special about 0x55AA?
<p>I have encountered 0x55AA in 2 scenarios:</p>

<ul>
<li>the final 2 bytes of boot sector in the legacy booting process contains <code>0x55AA</code>.</li>
<li>the first 2 bytes of the <a href="https://en.wikipedia.org/wiki/Option_ROM" rel="nofollow">Option ROM</a> must be <code>0x55AA</code></li>
</ul>

<p>So what's special about <code>0x55AA</code>?</p>

<p>The binary version of <code>0x55AA</code> is <code>0101010110101010</code>. Is it because it is evenly interleaved 0 and 1? But I don't see that's a strong criteria.</p>