[TUHS] unix v4 tape found

[Angelo Papenhoff via TUHS]

nice observations. Just a quick glance at numbers revealed around 4.1k
lines of diffs between matching ken/*.c and dmr/*.c files between nsys and v4,
and 1.1k between v4 and v5. Most changes are about the register keyword
however, and prefixing these variables with 'r'. De-registerifying the v4
kernel would allow for a fairer comparison to nsys. It would also be a
good step towards adding pipe support into the nsys kernel, which it is
unfortunately lacking. That would make it an actually usable complete UNIX
kernel i believe.

aap

On 20/12/25, segaloco wrote:
> On Friday, December 19th, 2025 at 17:53, Angelo Papenhoff via TUHS <tuhs at tuhs.org> wrote:
> 
> > I extracted it: http://squoze.net/UNIX/v4/
> >
> > aap
> 
> Some observations:
> 
> - In this init(1), /etc/getty is called as the only member of a single
>   member array "com".  In the current V5, /etc/getty is instead provided
>   as the only execution target for dfork.  The V5 manual adds that a
>   line in /etc/ttys indicates the specifiable program in this array.
>   The V6 manual removes again this idea of /etc/getty being one of many
>   possible targets in a table, making this a more V5-ish init(1) than
>   the current V5 copy.  Additionally, the V4 manual indicates that
>   init(1) still pulls TTYs from an internal table.  This init(1) is
>   using /etc/ttys.  Finally, utmp is still in /tmp in this tape, whereas
>   V6 sees it moved to /etc, as is the case in the current V5.
> 
> - The copy of wc(1) present matches the V5 manual page in that it
>   includes a number of options.
> 
> - Stty(1) here also is more V5-ish in that it does not implement the hup
>   options nor erase, kill, or ek.
> 
> Just a few, but some areas marking this as matching V5 well.  Probably
> tail end of calling it "V4" at all.
> 
> - Matt G.
> 
> V4->V5 /usr/man diff - https://gitlab.com/segaloco/mandiff/-/compare/v4...v5?from_project_id=44843539
> V5->V6 /usr/man diff - https://gitlab.com/segaloco/mandiff/-/compare/v5...v6?from_project_id=44843539