I just checked and Doom is available in the VMS Hobbyist program (http://www.openvmshobbyist.com/downloads.php?cat_id=3 http://www.openvmshobbyist.com/downloads

I just checked and Doom is available in the VMS Hobbyist program (http://www.openvmshobbyist.com/downloads.php?cat_id=3 http://www.openvmshobbyist.com/downloads.php?cat_id=3), so you should be able to get it to run under SIMH (http://simh.trailing-edge.com/ http://simh.trailing-edge.com/), if you're so inclined. Security Authorization not required here. :-)