amed file.  It reads the number of
  bytes to be written to the file from the BX and CX registers.  These
  registers are already initialised to the length of the file when we
  load a file in the debugger.  Since we have not modified these
  registers ourselves, we don't need to set them again.  In case you
  do need to set the BX and CX registers in a different situation, the
  commands to do so are <code>R BX</code> and <code>R CX</code>,
  respectively.
</p>
<p>
  Finally, the <code>W</code> command wri