Wow - I remember Coherent. Back then, distro-swapping for me meant juggling between Coherent, Yggdrasil Linux, and Xenix-286.
I never stuck with Coherent for long, since Yggradsil lead me to Slackware and the rest was history.
Apparently so for the MWC company. Some good stuff here:
https://en.wikipedia.org/wiki/Coherent_%28operating_system%29and
https://www.autometer.de/unix4fun/coherent/But what is a total freak out for me is remembering the MANUAL!
http://www.nesssoftware.com/home/mwc/manual.php?select=ComputersWhat makes the manual so fascinating for me now is that I can feel the author's own personality in trying to explain the system - which was often chided for being an "antique" system that mostly emulated the ATT Unix V7 from about 1978. Well, it was never meant to be big-time.
Anyway, what I find so fascinating is that rereading some of the material can *still* be useful - explaining commands in such a way that just one simple word, or other explanation can provide insight into corner areas.
It is a lot of fun to run through the commands and compare them to what Busybox has to offer.
Editors? How about micro-emacs. Or ED. I just picked up a book from last year about using the ED editor, and quite frankly, may not have needed it had I know this material had already been released.
I find the author's heavy use of cat > testfile to create examples, followed by ctrl-d to write the files very interesting compared to most tutorials today, which usually immediately launch into nano, or vi. Fascinatingly cool, since that's the way I try to teach the basics of default input and output to a new user before introducing them to an editor.
Maybe this is exactly where I got that notion from.
Anyway, it's a lot of fun to read a vintage manual, about a system that was already considered "vintage" material when published.