title: How were graphical DOS Games written?
body: <p>I always wondered how the DOS games like <a href="http://www.dosgamesarchive.com/download/skyroads/" rel="noreferrer">Sky Roads</a>, <a href="http://www.dosgamesarchive.com/download/turbo/" rel="noreferrer">Turbo</a>, <a href="http://www.abandonia.com/en/games/2/Aladdin.html" rel="noreferrer">Aladdin</a>, <a href="http://www.dosgamesarchive.com/download/duke-nukem/" rel="noreferrer">Duke Nukem</a>, <a href="http://www.dosgamesarchive.com/download/commander-keen-6-aliens-ate-my-baby-sitter/" rel="noreferrer">Commander Keen 6</a> were written.  I cannot find a good source. If I write a console application in C#, C++, Java etc.. It is always displayed and remains still. And it is always Text.</p>
  
  <ol>
  <li>How did they generate graphics?</li>
  <li>Were there any libraries to use?</li>
  <li>What languages they used?</li>
  </ol>
  
  <p>Any good source will be appreciated. </p>