Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!uflorida!haven!udel!mmdf
From: kyber!minixug!root@relay.eu.net
Newsgroups: comp.os.minix
Subject: Re: Once more. No more.
Message-ID: <20963@nigel.udel.EDU>
Date: 4 Jun 90 12:06:38 GMT
Sender: mmdf@udel.EDU
Lines: 36

>From article <20666@nigel.udel.EDU>, by Pat_Barron@transarc.com:
> "Vanilla" V7, straight from Murray Hill, did *not* run on the 11/34, since
> the kernel was big enough that it required separate I&D space.  DEC had
> a version they called "V7m", which had kernel overlays and could run on
> non-separate I&D space machines like the 11/34.  And it had fsck, too.
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Big mistake here: the '34 WAS A FULL UNIBUS MACHINE WITH 18-BIT
ADDRESS LINES AND SEPARATE I AND D SPACE !!!!!!!

Thus, the 11/34 has (yes, present time.  I still have some!) an addressing
capability of 256Kb (minus 8Kb UNIBUS space at the top).  One process could
be split into two segments each: I and D.  This allowed for much larger
processes to be run.

Remember, guys, that all major PDP-11's (so, not counting the '05, '10
(== 05), 20, ...) have a builtin MMU.  Therefore, this discussion is
pointless.  The PDP-11 is a 256Kb-machine, *NOT* a 64Kb-machine!
The 11/70 and all 22-bit Qbus machines have an addressing space of
4Mbyte.  Again, with or without SepID.

> What is I&D ?
I&D means "separate Instruction and Data space".  The chunks of code and
data of a program can be put into a single segment of memory, or they
can be put into separate segments, which then allows for larger processes!

> But other than that, it wasn't much different from regular V7.  Perhaps
> that's what you had?
_I_ had a vanilla 11/34 with 128Kw of memory running BSD2.9.
The other machine ran V7 at first, but we put BSD2.9 on that too,
since it was much faster.

Now, can we stop this part of the discussion, or move it to another
group?  I think we are boring lots of other people....

Fred van Kempen
MINIX User Group Holland