Newsgroups: comp.lang.c
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: PDP-11 data and function address spaces (was External ptrs and arrays)
Message-ID: <1989Nov12.004336.6637@utzoo.uucp>
Organization: U of Toronto Zoology
References: <530@dftsrv.gsfc.nasa.gov> <225800239@uxe.cso.uiuc.edu> <11567@smoke.BRL.MIL> <20642@mimsy.umd.edu> <1989Nov9.200332.8763@utzoo.uucp> <5121@ncar.ucar.edu>
Date: Sun, 12 Nov 89 00:43:36 GMT

In article <5121@ncar.ucar.edu> thor@stout.UCAR.EDU (Rich Neitzel) writes:
>>Dept. Of Really Fussy Nit-Picking:  relatively few pdp11s, and relatively
>>few pdp11 operating systems, supported split-space -- Unix on the 44/45/70
>>was just about the sole example 
>
>Alas, you have forgotten the 11/73 and 11/83. Also, RSX-11M+ uses I&D space
>extensively, even for the kernel...

If we're being really picky, the 73 was an lsi11, not a pdp11.  The 8n is
a slightly different story, but I can always hide behind the "just about"...

RSX-11M started using split-space pretty late in the game.  Early on, Unix
was notorious for giving the 11 MMU much more of a workout than any of the
DEC systems did.

>BTW, why do UNIX people seem so unfamiliar with DEC's Q-bus PDP's?

Probably because good ones did not become available until the pdp11's days
as a desirable Unix machine were already visibly ending.
-- 
A bit of tolerance is worth a  |     Henry Spencer at U of Toronto Zoology
megabyte of flaming.           | uunet!attcan!utzoo!henry henry@zoo.toronto.edu