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From: jnc at mercury.lcs.mit.edu (Noel Chiappa)
Subject: [COFF] [TUHS] Will pdp 11/04 run unix?
Date: Fri, 31 Jul 2020 17:26:01 -0400 (EDT)	[thread overview]
Message-ID: <20200731212601.383EA18C0C0@mercury.lcs.mit.edu> (raw)

    > From: Lars Brinkhoff

    > I have seen conflicting information in sources dating from the 70s when
    > the TV-11 and XGP-11 were very much in use.
    > For several reasons, I believe the TV-11 was the first machine attached
    > to the 10-11 interface, and the XGP-11 came second.  This would lend
    > some weak support for the theory that the first would be a 11/20 and the
    > second a 11/10.

Yeah, but Clem's note reinforces my vague memory that the XGP-11 was an
-11/20.

I wish we had a picture of the Knight TV system (the system, not a
terminal). It's a extremely significant system - I believe it my have been the
first bit-mapped computer display system ever; and thus the prototype, in some
sense, for the display of every single personal compupter (including phones)
now extant - and so there _ought_ to be a photo of it.  But looking online for
a while, I can turn up almost nothing about it! (I guess we should do a page
about it on the CHWiki...)

(Repeat my prior grump about how the AI Lab did all sorts of ground-breaking
stuff, because it was just 'tools', and not their main research focus, it's
hard to find out about a lot of it, e.g. the inter-ITS network file
system.)

But if you can find an image, even a low-res picture of that end of the AI Lab
machine room, we can tell what model the TV-11 is - early 11's had inteagrated
front panels, which are different for every model:

  http://ana-3.lcs.mit.edu/~jnc/tech/pdp11/PDP-11_Models.html

so you don't even need to be able to read anything to tell a /20 from a /10.
It was in a dual (I think - maybe triple, it's been a looooooong time :-)
rack which IIRC was along the side wall (i.e. the short building side) next to
the AI KA10 (which was sort of along the long wall, up in the corner).

I don't know if the XGP-11 code is still extant (my copy of the ITS filesystem
is offline right at the moment), but even if we look at the code, I'm not sure
we could tell; there are some _very minor_ programming differences between the
/20 and /10 (e.g. V bit on SWAB) - see the table at thd end of the PDP-11
Architecture Handbook - but I'd be aurprised if the code used any.

Surely there has to be _some_ picture of the machine room which shows it, even
if in the background.


    > I did bring it up with TK at some point.

Try RG, too.

    Noel


             reply	other threads:[~2020-07-31 21:26 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-31 21:26 jnc [this message]
  -- strict thread matches above, loose matches on Subject: below --
2020-07-31 13:56 jnc
2020-07-31 15:32 ` lars
2020-07-31 18:53 ` clemc
2020-07-31 19:38   ` lars
2020-07-31 19:40     ` clemc
2020-07-31 20:00     ` bgbaumgart
2020-07-31 20:05       ` clemc
     [not found] <20200730213720.109C018C0A5@mercury.lcs.mit.edu>
     [not found] ` <20200731071008.GA33933@indra.papnet.eu>
2020-07-31  7:57   ` lars

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