The only thing I would add is to find yourself a copy of Lion's book:
https://en.wikipedia.org/wiki/Lions%27_Commentary_on_UNIX_6th_Edition,_with_Source_Code

You can get a nicely bound version inexpensively from Amazon,
although there are PDFs in the wild too.    Like, others I would suggest
starting with Sixth Edition if you want to follow John.  The biggest
advantage of Seventh besides having more complete toolchains is that the
compiler matches K&R Version 1, so you are likely to have fewer issues, you
will already be giving up ANSI (as described in K&R2).  I started with
Fifth years ago in the early/mid-1970s but quickly got Sixth's so I have
little memory of it.  I have played with it on simh since frankly, the
differences between 5 and 6 are not going to be huge from a learning
standpoint.
ᐧ

On Wed, May 5, 2021 at 2:09 PM Noel Chiappa <jnc@mercury.lcs.mit.edu> wrote:

>     > From: Saif Resun
>
>     > I want to use the 5th edition UNIX operating system.
>     > ...
>     > I want to use it using the SimH emulator but there's no guide about
>     > how to install it or use it.
>
> As they say,'Google is your friend':
>
>   https://gunkies.org/wiki/Running_Unix_v5_in_SIMH
>
> Also, V6 Unix is very similar to V5 (the main difference, IIRC, is that V6
> supports so-called 'Split I/D space' on the PDP-11) so anything for V6 will
> mostly apply to V5:
>
>   https://gunkies.org/wiki/Running_UNIX_v6_in_SIMH
>   https://gunkies.org/wiki/Installing_UNIX_v6_(PDP-11)_on_SIMH
>   https://gunkies.org/wiki/Installing_UNIX_Sixth_Edition_on_Ersatz-11
>
> Have fun!
>
>         Noel
>