After learning of Dave's death, a professor I very much enjoyed as a U of Delaware EE student, I came across this page https://www.eecis.udel.edu/~mills/gallery/gallery9.html This reminds me of his lectures, the occasional 90 degree turn into who knows what, but guaranteed to be interesting.  And if anyone has a UDel Hollerith card they're willing to part with, please get in touch.  I have none.  :-( Mike Markowski