[TUHS] DECtapes under the UNIX room floor

[Thalia Archibald via TUHS]

Interesting. I’ve reviewed Dennis_Tapes before, but different bits stand out
this time.

On May 5, 2026, at 22:57, Warren Toomey wrote:
>            The following quiz was distributed at the Salt Lake City conference
>    by Rob Pike... Jim McKie had the best score for an individual (57) and was
>    awarded an authenticated 1972 DECtape containing UNIX Version 2.

Neat. I scanned a paper from this 1984 USENIX.
    https://archive.org/details/nielsen_object_kernel_1984

>    With `tap', the times associated with the files were recorded
>    in pre-modern units: sixtieths of a second, from an origin that
>    changed.

Was there a precedent for the choice of sixtieths of a second?

>    dmr
>            Random stuff from my directory.  Most probable dates: 1972.
>            The `paper' directory contains a version
>            of the original SOSP Unix paper (haven't compared
>            it with the CACM version).

This should be rendered and added to TUHS.

>            cgd appears to be an experiment in converting
>            Fortran threaded code to machine language,
>            using a warmed over version of the earliest C
>            code generator.  It's written in NB, not C.

This would be a great reference for reconstructing B/NB, along with the
well-known last1120c and prestruct-c!

>            notes1 and notes2 are evidently notes I made for myself
>            for a talk on unix.  They are quite interesting.

“UNIX is running on at least five PDP-11”. Modified 1972-03-15.
This should also be rendered.

>    dmr2
>            the let directory contains drafts of a bunch of letters
>            to people who asked about unix in early days.  (lett6
>            is to andy tanenbaum).

Dr. Paul C. Abegglen from the University of Utah requested UNIX on 1973-11-21
and Dennis replied in lett8. I wish I knew more about him, but I’ve found very
little. He’s from the Chemistry Department, not computer graphics like Martin
Newell (who apparently received UNIX V4 in June 1974), so a connection seems
tenuous. Martin recognized the name, but nothing else, when I asked.

>    games
>            Ken's work on various games.  Check out chomp/c0.c,
>            which has a briefly-existing form of structure
>            declaration using parentheses instead of braces.


This has the source to bj, moo, chess, wump, and ttt (but not cubic)!

>    ken
>            check out the values of the AT&T Savings plan in the
>            early 70s (plan), and what interested Ken's son (corey/*)
>            then.


distr/ has Ken’s 1975 licensee list that I’ve analyzed, but I glossed over
dsk{b,m,s}, which are the listings of the binary, manual, and source
distributions.

pwd/ is a password cracker.

>    ken-sky
>            A bunch of interesting old ken stuff (eg a version of
>            the units program from the days when the dollar fetched
>            302.7 yen)

nih.a is Ken’s trusting trust backdoor (https://research.swtch.com/nih).

>    sys-dsu
>            This system didn't come directly from us.  After
>            poking around it for a while I found a file containing
>            this (in cr.h):
> 
>            /*****************************************************************
>             **                                                             **
>             **                U C L A  Data Secure Unix                    **
>             **                                                             **
>             **                     Copyright 1977                          **
>             **                                                             **
>             **    Mark Kampe, Charles Kline, Gerald Popek, Evelyn Walton   **
>             **                                                             **
>             *****************************************************************/
> 
>            So, it appears that `dsu' is `data-secure unix' and this is a
>            record of one of the early security projects!  They must
>            have sent it to us.  Might be fun to examine it; I suppose
>            we should tell Gerry Popek of its existence.

It would be interesting to analyze this to tease out an intermediate snapshot
around January 1977.

>    unix
>            This is probably a `boot' tape; it has binary images of
>            the system and some raw utility programs for use when booting
>            (memory testers, loaders for diagnostics, and the like).

This is dated 1975-07-14. Has it been analyzed?

Thalia