There's also a problem in E3M09, the Adolf Hitler level. The fireballs that the ghosts make move almost as fast as I can! On the older computers, the fireballs move very slowly; so slowly that I laugh at them. I remember watching a Youtube video that explained why this happened, but I can't remember how it works. It's probably out of my watch history anyway.
One last problem. The demo makes the gameplay less smooth. This happens all the time in DOS Box. Is there a way to fix it without slowing down the game?