On Sun, Mar 22, 2020 at 3:44 PM Warren Toomey <
wkt@tuhs.org> wrote:
On Sun, Mar 22, 2020 at 02:49:03PM -0600, Warner Losh wrote:
> On Sun, Mar 22, 2020 at 2:20 PM Warren Toomey <[1]wkt@tuhs.org> wrote:
>
> On Sun, Mar 22, 2020 at 09:58:29AM -0600, Warner Losh wrote:
> > "from a working C compiler for 2nd Edition UNIX."
> > Does anybody know for sure, or can provide more insight into the
> last1120c.tar.g
> > z file to help disambiguate?
> Yes, all the details are on Dennis' web page:
> [2]https://www.bell-labs.com/usr/dmr/www/primevalC.html
>
> Magic historical 8-ball sez: situation unclear, try again.
> So could be 2nd, 3rd or 4th edition given the date range.
Someone from the Labs here on the list might be able to clarify. I'm sure
I heard that they start with the PDP-11/20 and got an 11/45 around the time
of Second Edition. So the "last1120c" was the C compiler around the time of
Second Edition.
According to my history of early unix talk, they started to transition to 11/45 in the 2nd edition, and had completed the rewrite by the 4th edition. The 2nd and 3rd editions had, at least according to their intros, some support for the 11/20, but it is ambiguous now that I re-read it:
2nd edition (June '72)
"Also, not all installations have the latest version of all the software. In particular, the assembler and loader have just undergone major reorganizations in anticipation of a UNIX for the PDP-11/45"
3rd Edition goes farther (Mar '73):
"In particular, any system which uses a PDP-11/20 processor will not include all the software described herein, nor will the software behave in the same way. The second, or even the first edition of this manual is likely to be more appropriate."
By the 4th edition (Nov '73), The PDP-11/20 is gone, not even referenced....
"In particular, the information in this manual applies only to UNIX systems which operate under the C language versions of the system. Installations which use older versions of UNIX will find earlier editions of this manual more appropriate to their situation."
So the outward messaging of the manual, at least, was "We're running away from the 11/20, and you should too if you want to run the latest code." But it's not clear to me, since we don't have good sources from the actual 2nd or 3rd edition to trace where this came in, or if the 11/20 lived on a little past the 4th edition and had sources freshly loaded on it sometime after the compiler was written...
Warner