Every once in a while, you come across an old book (in my case, at a Half Price Books near the Seattle-Tacoma International Airport for $10) and read it to see how things used to be. I read a first edition copy, copyright 1969 in the Prentice-Hall Series in Automatic Computation. Some interesting tidbits here: a novel mathematical formalization of feedback loops, discussions of econometrics and Jay Forester's System Dynamics, and implementations of simulation quite literally by punchcard programming. The math is solid (the author as a M.Sc. in the subject, so) and the implementation details are quite interesting, for those who work on simulation, computing, and the data and information sciences would do well to appreciate how easily we can compute by opening up Vim, VSCode, Notepad++ instead of grabbing a holepunch and paper card.