# File lib/DSK.rb, line 102
  def save_as(filename)
    if !(filename=~/\.gz$/).nil? then
                        require 'zlib'
      f=Zlib::GzipWriter.new(open(filename,"wb"))
    else
      f=open(filename,"wb")
    end    
    f<<@file_bytes
    f.close
  end