[TUHS] v7 bas - "Ken Thompson's BASIC"

So, I was bemoaning the fact that I couldn't really make sense of the bas command in v7. In sysv2, it works and is similar enough to modern dialects that I was able to get a simple example working, but with v7, the best I was able to do was use it interactively, as a calculator. Then I went looking for v7 videos on youtube and came across this Dr. Dave's Diversions video: https://www.youtube.com/watch?v=LZUMNZTUJos In it Dr. Dave demos a few simple versions of 99 bottles of beer in v7. Wow! I wondered how he'd glommed the inner workings of bas - did he read a book, just know it naturally, phone a friend, or what? Well, as it turned out, he... wait for it... read the bas(1) man page! Wha?! Ridiculous. So, I pulled out my v7 phone book and read the bas(1) man page and sure enough, it was all there... how '_' is used for negation, how those arcane for loops work, arrays?!, function calls?!, etc and so on, all in 3 short pages. So, two observations: 1. Those man pages from back in the day - wow. So terse, yet so well written. With a little help from a friend (thanks, Dr Dave), they're really all you need, sometimes. 2. Those early apps - wow. So obscure these days, but so ahead of their time, too (thanks, Ken for making Dec 2021 interesting by doing what you did back in the early 70's). And a question (you knew it was coming): Besides the bas(1) page, is there anything else written on Ken's basic out there in the wild? Oh, and a bonus question, draw and erase from v5 appear to still be around in v7, but not documented in the man page. Did it work and has anyone written a Tektronix 611 emulator that works with v7? Thanks, Will