title: NASM x86 16-bit addressing modes
body: <p>I am having trouble with pointing to a address and write in my case a variable of byte in size. This gives me the error "error: invalid effective address":</p>
  
  <pre><code>mov byte[AX], byte 0x0
  </code></pre>
  
  <p>After some trail and error i tested the same but with EAX. This compiles just fine:</p>
  
  <pre><code>mov byte[EAX], byte 0x0
  </code></pre>
  
  <p>What am I missing here?</p>