title: Why was NOP assigned to 0x90 in x86 assembly?
body: <p>Why was <code>nop</code> assigned to <code>0x90</code> on intel x86 assembly?</p>
  
  <p>Intuitively I would expect that <code>0x00</code> would map to <code>nop</code> (which is also <code>xchg eax, eax</code> at intel x86) as it is the case for <code>ARM A32</code> and some other architectures.</p>