[TUHS] Whence 1st Edition Unix Kernel Assembly?

Warren Toomey wkt at tuhs.org
Mon Apr 28 20:48:53 AEST 2008

On Thu, Apr 24, 2008 at 10:53:30AM -0700, James A. Markevitch wrote:
> I have been referring to this as version "1.5" since the date is later
> than the first edition manual, but before the second edition manual.
> Does anyone know if it's truly V1 of the kernel, or something between
> V1 and V2?

The date on the first page of the memo (PDF) is September 1972. That puts
the memo after 2nd Edition (June 1972) and 3rd Edition (Feb 1973).

The s2 tape in the Unix Archive has binaries which are dated mainly in
1972, spread from January thru to December, so they should be
contemporaneous with the kernel in the PDF.

The 1st Edition manuals are on-line on Dennis Ritchie's web page at:
I have a photocopy of the 2nd Edition manuals from Norman Wilson; I will
scan them in as a bunch of tiffs. The 3rd Edition manuals are at
but they refer to the C version, so they may not be as useful here.

> Does anyone have utilities earlier than the "1972" stuff from TUHS?

No, the s1 and s2 tapes are the earliest machine readable files that
we have.

I'm assuming that some of you are keen to see it running. It's going to
take a lot of work, especially on the debugging side. The existing 1972
binaries are already executable using my Apout emulator, so that will
help in two ways: we can run the old assembler, and we can tell if a bug
was in a userland binary and not in the kernel.

If I get a chance, I should try to compare the 1e and 2e manuals, to
outline the kernel API differences, as this might help us to determine
which binaries we have that will run on the PDF kernel.


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