Hi folks, In case you're interested: I've published a couple videos on these ancient Unix tools, sharing including some language details and showing them in action on v7 and System III, respectively: Ken Thompson's bas(1): https://youtu.be/LZUMNZTUJos Dick Haight's bs(1): https://youtu.be/ELICIa3L22o Thanks much for the help from TUHS, Mashey, Kernighan, McIlroy, and others cited therein. Peace, Dave -- dave(a)plonka.us http://www.cs.wisc.edu/~plonka/