If anyone here is interested in checking out a real life Unix Version 7 operating system running on simulated hardware (PDP-11/70, I think) check here:
http://museum.sysun.com/museum/unix7.html
Here's some interesting propaganda - type "1" (without quotes) at the prompt - it calls /bin/1... kind of funny.
I'm running the same disk image on a simulator on a personal machine, and the timestamps indicate that many of these files were last modified on June 8, 1979!! How's that for historic?!

If you are feeling adventurous, you can download your own simulator set, and disk images, to play with Unix as old as v5, although it takes even longer to get used to for modern Unix users. For example, v5 through v7 didn't even have an interactive delete function. You had to use the "#" sign; for example:
/ettg##c/n#mount /dev#v/rl1 /mnt would equal
/etc/mount /dev/rl1 /mnt. Likewise, the @ sign would clear out the entire line... If you accidentally hit the delete/backspace key, it'll terminate the current process...
Heck, v5 didn't even utilize the "cd" command... you actually had to type out "chdir".

Any way, have fun, and be sure to check out the other simulators available to use, and for download! Lots of fun!

Hell... I worked on it back in 1982 at Bell Labs.
It's nice to know the good old stuff is still around
even if it's in a museum.

.. yeah.. it was really fun with those systems... I remember even having to explicitly set "rm -i" as an alias (I think that was an Ultrix system, but I can't remember)....

... it's all good stuff.. ;>

- dEvNuL