[TUHS] Thompson at Berkeley on an 11/70

Jeremy C. Reed reed at reedmedia.net
Fri Apr 10 11:44:01 AEST 2015

On Fri, 10 Apr 2015, Jacob Goense wrote:

> If it was stock V6 initially, what were they waiting for? Legal stuff?
> If it was 1975 Bell UNIX, can I reconstruct this using the 54 patches
> collected by Mike O'Brien[2], or is that going to be way off from what
> Thompson left in Urbana-Champaign with Greg Chesson in 1975?

When Thompson arrived, the Math and Statistics department had a shared 
machine running RSTS-E and Unix part time. McKusick wrote that the 11/70 
arrived in Fall of 1975 and it was installed with Version 6. (Marshall 
Kirk McKusick. A BERKELEY ODYSSEY: Ten years of BSD history. Unix 
Review. January 1985. Volume 3. Pages 31-42.) But the Quarter Century 
book (page 155) says it was upgraded to V6 after Thompson left (he told 
me he left right after exams in June). Thompson told me he brought up 
the 11/70 for the EECS (but didn't tell me the version). (Jolitz and 
Allman told me the shared 11/45 also used for CS classes ran v6 (and 
RSTS-E) but I don't when it was upgraded to v6. The INGRES group also  
their own dedicated computer which ran 5th Edition and then v6.)

(Thompson told me that he wrote his Pascal between quarter 1 and 
quarter 2 and that Fabry used it for his instruction the next quarter. 
Fabry told me that Thompson's students completed their programming 
assignments using the Cory Hall PDP-11/70 running Unix.)

O'Brien suggested to me that the annotated fifty changes wouldn't apply 
to Berkeley's already hacked kernel.

Allman and Fabry told me that in their code reading sessions, Thompson 
had the John Lions' annotated code for the v6 kernel. I believe these 
(Lions') lecture notes were from May 1976 (so not much time before 
Thompson left).

> [2] Hidden in /usr/sys/v6unix/unix_changes in one of the Spencer tapes
> http://www.tuhs.org/Archive/Applications/Spencer_Tapes/unsw3.tar.gz

Thank you so much for pointing me to this. Too bad there aren't dates 
mentioned in the code or diff files. I am authoring a book that includes 
this same story (and I had basically the same questions).

  Jeremy C. Reed

echo 'EhZ[h ^jjf0%%h[[Zc[Z_W$d[j%Xeeai%ZW[ced#]dk#f[d]k_d%' | \
  tr            '#-~'            '\-.-{'

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