From mboxrd@z Thu Jan  1 00:00:00 1970
From: aap@papnet.eu (Angelo Papenhoff)
Date: Wed, 18 Jan 2017 07:53:51 +0100
Subject: [TUHS] [TUHS} PDP-11, Unix, octal?
In-Reply-To: <CAEoi9W6A9ttt-LAhKAGFeGf5UaVhiqoVfaNmJ3dooB2obPqNkg@mail.gmail.com>
References: <20170118023358.BE5C818C095@mercury.lcs.mit.edu>
 <50a7fbcbb6af280eb108fff1361c37ee1718bff0@webmail.yaccman.com>
 <CAEoi9W6A9ttt-LAhKAGFeGf5UaVhiqoVfaNmJ3dooB2obPqNkg@mail.gmail.com>
Message-ID: <20170118065351.GA57704@indra.papnet.eu>

On 17/01/17, Dan Cross wrote:
> A question about 36 bit machines....
> 
> In some of the historical accounts I've read, it seems that before the
> PDP-11 a pitch was made for a PDP-10 to support the then-nascent Unix
> efforts. This was shot down by labs management and sometime later the
> PDP-11 arrived and within a decade or so the question of byte width was the
> creatively settled for general purpose machines.
> 
> The question then is twofold: why a PDP-10 in the early 70s (instead of,
> say, a 360 or something) and why later the aversion to word-oriented
> machines? The PDP-7 was of course word oriented.
> 
> I imagine answers have to do with cost/performance for the former and with
> regard to the latter, a) the question was largely settled by the middle of
> the decade, and b) by then Unix had evolved so that a port was considered
> rather different than a rewrite.  But I'd love to hear from some of the
> players involved.

Doesn't exactly answer your question, but from the "Oral History of Ken
Thompson":

Q: As I recall this - once upon a time weren't you trying to get a
PDP-10 or something like that for the lab?

Ken Thompson: Yes, we were arguing that the Multi[cs] machine should be
replaced with a PDP-10. And there was such a huge backlash from
Multi[cs] that it was pretty soundly turned down. It was probably a good
idea, the -10 is a kind of trashy machine with 36 bits - the future just
left it behind.


"the -10 is a kind of trashy machine with 36 bit"
I'm not sure whether I can still like UNIX now :( I hope this is the bad
(?) experience with Multics on the GE-645 speaking.

"the future just left it behind"
More like DEC didn't want internal competition with the VAX.

aap