Link: https://www.howtogeek.com/unix-v4-is-back-i-booted-the-1973-os-and-it-made-me-weirdly-happy/

Last year, researchers at the University of Utah found a copy of Unix lying around on a 9-track magnetic tape. It's special because that version of Unix was lost until it was recovered from that magnetic tape 52 years later. The researchers managed to successfully reconstruct it, and then they made the copy public. Anyone can download it and run it inside a virtual machine. So I did just that, and it made me so giddy to use it.

What is UNIX V4, and why should you care?
If you care about computer history at all, Unix lore is utterly fascinating. There was a time when operating systems were tied to their hardware. There was no way to move an operating system to hardware that it wasn't specifically programmed to run. Imagine only being able to install Android on one specific phone model or Windows on just one specific hardware configuration. We take it for granted today, but Unix V4 made 'portable' operating systems possible

The text editor sounds crazy to use.

ed is the standard text editor.

I am aware (even though I've only ever used nano), I am refering to the way the in which it was used.

ed is available on all modern unix-like oses, you can try it 😉 Vi inherit his modal system from ed