If all you want to do is read using a Web browser, then you can see what's happening here using the Newsgroup Archive, NARKIVE, to get there from here:
<
https://comp.sys.unisys.narkive.com/ >
The nice thing about this is that the spam isn't archived and so doesn't show up.
NovaBBS also lets you see what's going on using a Web browser as well :
<
https://www.novabbs.com/computers/thread.php?group=comp.sys.unisys >
I *think* that the latter lets you post as well although you have to register to do so first.
I haven't tried this so I don't know for sure.