Phil Anderson, W0XI, SK
I saw that Phil Anderson, the person behind Kantronics and also the Crystal Set Society has died:
https://www2.ljworld.com/life-events/obituaries/2023/jul/02/philip-anderson/
https://www.midnightscience.com/
Somewhere I have a cartridge for my Atari 400/800 from Kantronics which I think I bought from Spectronics in Oak Park, IL in the 1980s. As I recall it wasn't an actual cartridge, it was a circuit board - but it fit into the cartridge socket no problem.
Here is a site with the manual:
http://www.atarimania.com/utility-atari-400-800-xl-xe-hamsoft_33421.html
I will have to see if I can find that cartridge - of course then I'll have to find one of the Ataris and a monitor and also come up with some interface hardware - maybe I'll just forget the whole thing :)
Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm