make a downloadable text file in javascript (no server)

Continuing my Atari kick... I've started work on title-screen-titan, a browser tool for the esoteric art of making 48-pixel graphics on the Atari 2600. 

One thing I like to do with my Atari tools is provide code you can run right away. 

This page taught me how to build up one click downloads without hitting my server:

function download(filename, text) {
  var element = document.createElement('a');
  element.setAttribute('href', 
    'data:text/plain;charset=utf-8,' 
        + encodeURIComponent(text));
  element.setAttribute('download', filename);

  element.style.display = 'none';
  document.body.appendChild(element);

  element.click();

  document.body.removeChild(element);
}

Then I just called download() in the onclick of a button. 

I also updated my old batari Basic kickstart tutorial - I do love writing to help people learn to do new stuff.