Here's the work from one of my students. He read somewhere that you could put oscilloscopes into X,Y mode to print graphics (I think the original post talked about porting Quake to an oscilloscope), and so he decided to play around during the lunch break. Our oscilloscopes aren't the best in the world, but the results aren't too bad!
He found an old cathode ray oscilloscope, we'll try that next week to see what happens.