title: Why is such a small assembly program so slow?
body: <p>I have the following assembly program which displays the letter 'z' and then exits:</p>
  
  <pre><code>mov dl, 'z'
  mov ah, 2h
  int 21h
  mov ah, 4Ch
  int 21h
  </code></pre>
  
  <p>I assembled it with NASM and the resulting file only contains those instructions. (10 bytes) I put 1000 calls to this program in a batch file, and then 1000 calls to</p>
  
  <pre><code>echo z
  </code></pre>
  
  <p>and the echos run about 10x faster. Does anyone know what would be causing this program to run so slowly? Thanks in advance.</p>