LSX is trimmed 6th ed. Unix for running on LSI-11 machines, apparently ported to UKNC (I don't know where the sources are, the original LSX is https://www.tuhs.org/cgi-bin/utree.pl?file=LSX )
Discussion: https://www.old-games.ru/forum/threads/ehmuljatory-uknc-i-dvk.50279/page-7
Data for emulator: https://www.old-games.ru/forum/attachments/unix_systema-rar.184828/
Just start the emulator, connect the unix.dsk as MZ0 in the menu and select the first option 1+enter in the boot menu. Then, after the ":" prompt, the name of the kernel (lsx) is entered, after a while it boots into singleuser (prompt "#"), ls, chdir, etc. commands work there. There is also a great editor 'ed' :).
The disk image can be mounted via https://github.com/jaylogue/retro-fuse (must install 'sudo apt install libfuse-dev' before translating to Ubuntu), then the image can be mounted via ./v6fs .../unix.dsk /mnt