Hrm. Interestingly, someone posted the sources to Amdahl UTS here two days ago. Which is apparently the same thing, just ported to run on IBM S/370 under VM/370.

[1] https://news.ycombinator.com/item?id=28560334

Including two videos explaining how to install it, and all the requirements under Hercules, and many, many other links.

Now I'm wondering if it would be possible to install an IRC-client under it just for giggles, or if it would be possible at all?

Sigh. So much to try! :-)