BBN TC2000

An MC88100 emulator running nX — BBN's 4.3 BSD for the Butterfly TC2000 — booted from a 1989 install tape, compiled to WebAssembly.
Source code

What you are looking at

Pressing Boot the machine downloads the kernel and the tape's UFS filesystem, then starts the emulator at the kernel's entry point. All of the [nx] messages are coming from the actual kernel, exactly as it would have been seen on a real TC2000 in 1989.

When the kernel reaches the point where the swapper goes idle, the emulator starts /bin/sh off the tape as a genuine nX process, and routes the terminal to it.

Things to try at the # prompt