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Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth

From ted@loft.tnolan.com (Ted Nolan <tednolan>)
Newsgroups comp.os.linux.misc, alt.folklore.computers
Subject Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth
Date 2025-08-29 20:52 +0000
Organization loft
Message-ID <mhei7qFagenU1@mid.individual.net> (permalink)
References <e4ucnb1I-5IIqur1nZ2dnZfqnPudnZ2d@giganews.com> <108k7rn$e12$4@news.misty.com> <108l4vk$77t$1@gal.iecc.com> <108su32$3e8$1@news.misty.com>

Cross-posted to 2 groups.

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In article <108su32$3e8$1@news.misty.com>,
Johnny Billquist  <bqt@softjar.se> wrote:
>On 2025-08-26 22:21, John Levine wrote:
>> According to Johnny Billquist  <bqt@softjar.se>:
>>> The claim has another problem. While an x86 might be considered more
>>> powerful in some ways, it does not have nearly as capably MMU as the
>>> PDP-11,
>> 
>> The 8086 had no MMU at all, but small model code gave you 64K each of
>> instructions and data, the same as what the 11's MMU gave you. There was no
>> hardware protection so a malicious or badly broken program could crash the
>> system but they rarely did. That would require instructions that the C
>compiler
>> didn't generate.
>
>If we were to compare the memory layout/concepts of the PDP-11 and x86, 
>with an eye to powerful and capable, then the PDP-11, which have an MMU, 
>don't need to allocate 64K of memory for each process. In fact, it only 
>need to allocate as much memory as the process actually require, and any 
>addressing outside of that would trap and you'd get an signal in your 
>process. So you can easily squish in many more processes in the same 
>amount of memory.
>The next couple of points I don't know exactly when they came about for 
>the PDP-11, so it might have been a bit later, but I think it's still 
>valid as a comparison against the x86 here.
>Stack, on the PDP-11 is dynamically grown and allocated while the 
>program is running, so you don't have to pre-allocate all that memory 
>either, even though it can grow up to close to 64K.
>
>But even more important, on the PDP-11, there is support for overlaid 
>programs, which makes heavy use of the MMU. Basically, programs can be 
>way larger than 64K code. You can place functions in different overlays, 
>and call between them, and you can run up to many hundred of K of code 
>very easy and straight forward on the PDP-11, and it's all because the 
>MMU helps you out with it, moving the pages mapping around as needed.
>

My memory is that at leat for BSD Unix, overlays were not supported until
um, 2.9BSD I think, and that using them was not at all straight-forward.
It may have been easier for official DEC OSes...
-- 
columbiaclosings.com
What's not in Columbia anymore..

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Re: Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Johnny Billquist <bqt@softjar.se> - 2025-08-26 14:04 +0200
  Re: Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth The Natural Philosopher <tnp@invalid.invalid> - 2025-08-26 13:13 +0100
    Re: Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Johnny Billquist <bqt@softjar.se> - 2025-08-26 15:23 +0200
      Re: Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth The Natural Philosopher <tnp@invalid.invalid> - 2025-08-26 19:43 +0100
  Re: Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth John Ames <commodorejohn@gmail.com> - 2025-08-26 08:31 -0700
    Re: Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth "Kerr-Mudd, John" <admin@127.0.0.1> - 2025-08-26 17:52 +0100
      Re: Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth John Ames <commodorejohn@gmail.com> - 2025-08-26 10:01 -0700
      Re: Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth The Natural Philosopher <tnp@invalid.invalid> - 2025-08-26 19:44 +0100
    Re: Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Rich <rich@example.invalid> - 2025-08-26 17:26 +0000
      Re: Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth ted@loft.tnolan.com (Ted Nolan <tednolan>) - 2025-08-26 17:47 +0000
        Re: Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth scott@slp53.sl.home (Scott Lurndal) - 2025-08-26 18:19 +0000
        Re: Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth John Levine <johnl@taugh.com> - 2025-08-26 20:25 +0000
          Re: Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth The Natural Philosopher <tnp@invalid.invalid> - 2025-08-26 21:44 +0100
          Re: Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth ted@loft.tnolan.com (Ted Nolan <tednolan>) - 2025-08-26 21:12 +0000
    Re: Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth antispam@fricas.org (Waldek Hebisch) - 2025-08-27 22:09 +0000
      Re: Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-27 23:00 +0000
        Re: Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth antispam@fricas.org (Waldek Hebisch) - 2025-08-28 09:10 +0000
        Re: Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth "Carlos E.R." <robin_listas@es.invalid> - 2025-08-28 13:02 +0200
          Re: Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth The Natural Philosopher <tnp@invalid.invalid> - 2025-08-28 12:17 +0100
  Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth John Levine <johnl@taugh.com> - 2025-08-26 20:21 +0000
    Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Alexander Schreiber <als@usenet.thangorodrim.de> - 2025-08-27 16:40 +0200
      Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth John Ames <commodorejohn@gmail.com> - 2025-08-27 08:30 -0700
        Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Alexander Schreiber <als@usenet.thangorodrim.de> - 2025-08-28 10:09 +0200
      Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth "Kerr-Mudd, John" <admin@127.0.0.1> - 2025-08-27 19:04 +0100
        Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-27 22:58 +0000
        Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth c186282 <c186282@nnada.net> - 2025-08-28 04:06 -0400
      Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-27 22:58 +0000
      Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth c186282 <c186282@nnada.net> - 2025-08-28 03:26 -0400
        Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Peter Flass <Peter@Iron-Spring.com> - 2025-08-28 15:56 -0700
          Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-29 00:58 +0000
      Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2025-08-29 06:50 +0000
        Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth The Natural Philosopher <tnp@invalid.invalid> - 2025-08-29 10:50 +0100
          Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Rich <rich@example.invalid> - 2025-08-31 20:15 +0000
        Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Alexander Schreiber <als@usenet.thangorodrim.de> - 2025-08-29 12:46 +0200
          Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Richard Kettlewell <invalid@invalid.invalid> - 2025-08-29 14:28 +0100
          Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Bob Eager <news0009@eager.cx> - 2025-08-29 14:40 +0000
            Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Alexander Schreiber <als@usenet.thangorodrim.de> - 2025-08-29 23:13 +0200
              Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-30 03:28 +0000
          Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2025-08-29 23:51 +0000
            Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-30 03:27 +0000
              Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth c186282 <c186282@nnada.net> - 2025-08-30 00:25 -0400
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth cross@spitfire.i.gajendra.net (Dan Cross) - 2025-08-30 12:19 +0000
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth "Carlos E.R." <robin_listas@es.invalid> - 2025-08-31 13:37 +0200
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Alexander Schreiber <als@usenet.thangorodrim.de> - 2025-08-31 18:23 +0200
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth rbowman <bowman@montana.com> - 2025-08-31 17:37 +0000
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-31 22:24 +0000
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth "Carlos E.R." <robin_listas@es.invalid> - 2025-09-01 02:35 +0200
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Peter Flass <Peter@Iron-Spring.com> - 2025-09-01 07:55 -0700
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Rich <rich@example.invalid> - 2025-09-01 11:23 +0000
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth antispam@fricas.org (Waldek Hebisch) - 2025-09-01 11:52 +0000
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth "Carlos E.R." <robin_listas@es.invalid> - 2025-09-01 14:11 +0200
              Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth candycanearter07 <candycanearter07@candycanearter07.nomail.afraid> - 2025-08-30 18:30 +0000
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-30 22:20 +0000
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Alexander Schreiber <als@usenet.thangorodrim.de> - 2025-08-31 18:25 +0200
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2025-09-02 21:22 +0000
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth scott@slp53.sl.home (Scott Lurndal) - 2025-09-02 21:46 +0000
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-09-02 22:44 +0000
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2025-09-02 23:55 +0000
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Johnny Billquist <bqt@softjar.se> - 2025-09-03 01:22 +0200
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth antispam@fricas.org (Waldek Hebisch) - 2025-09-03 01:13 +0000
            Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Rich <rich@example.invalid> - 2025-08-31 20:20 +0000
            Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Anssi Saari <anssi.saari@usenet.mail.kapsi.fi> - 2025-09-01 14:46 +0300
              Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth scott@slp53.sl.home (Scott Lurndal) - 2025-09-01 14:33 +0000
              Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Peter Flass <Peter@Iron-Spring.com> - 2025-09-01 08:03 -0700
        Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth "Carlos E.R." <robin_listas@es.invalid> - 2025-08-29 14:53 +0200
        Re: PC/IX, Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth John Levine <johnl@taugh.com> - 2025-08-29 17:09 +0000
          Re: PC/IX, Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth The Natural Philosopher <tnp@invalid.invalid> - 2025-08-29 19:18 +0100
            Re: PC/IX, Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2025-08-29 23:51 +0000
              Re: PC/IX, Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth rbowman <bowman@montana.com> - 2025-08-30 05:54 +0000
                Re: PC/IX, Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth c186282 <c186282@nnada.net> - 2025-08-30 03:06 -0400
                Re: PC/IX, Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth The Natural Philosopher <tnp@invalid.invalid> - 2025-08-30 08:28 +0100
                Re: PC/IX, Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth c186282 <c186282@nnada.net> - 2025-08-30 05:30 -0400
                Re: PC/IX, Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth The Natural Philosopher <tnp@invalid.invalid> - 2025-08-30 11:59 +0100
                Re: PC/IX, Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth c186282 <c186282@nnada.net> - 2025-08-30 08:26 -0400
                Re: PC/IX, Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth rbowman <bowman@montana.com> - 2025-08-30 20:36 +0000
                Re: PC/IX, Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth rbowman <bowman@montana.com> - 2025-08-30 20:31 +0000
                Re: PC/IX, Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2025-09-02 21:22 +0000
                Re: PC/IX, Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth rbowman <bowman@montana.com> - 2025-09-03 03:10 +0000
              Re: PC/IX, Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth The Natural Philosopher <tnp@invalid.invalid> - 2025-08-30 08:13 +0100
        Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth scott@slp53.sl.home (Scott Lurndal) - 2025-08-29 22:27 +0000
    Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Johnny Billquist <bqt@softjar.se> - 2025-08-29 21:12 +0200
      Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth ted@loft.tnolan.com (Ted Nolan <tednolan>) - 2025-08-29 20:52 +0000
        Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-08-29 23:34 +0000
          Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Johnny Billquist <bqt@softjar.se> - 2025-08-30 11:51 +0200
          Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth scott@slp53.sl.home (Scott Lurndal) - 2025-08-30 15:54 +0000
            Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Peter Flass <Peter@Iron-Spring.com> - 2025-08-30 12:13 -0700
              Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth ted@loft.tnolan.com (Ted Nolan <tednolan>) - 2025-08-30 19:27 +0000
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Peter Flass <Peter@Iron-Spring.com> - 2025-08-30 14:45 -0700
              Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2025-09-02 21:22 +0000
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth John Ames <commodorejohn@gmail.com> - 2025-09-02 14:45 -0700
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth scott@slp53.sl.home (Scott Lurndal) - 2025-09-02 22:03 +0000
            Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Rich Alderson <news@alderson.users.panix.com> - 2025-08-30 19:34 -0400
          Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth "Carlos E.R." <robin_listas@es.invalid> - 2025-08-31 13:44 +0200
            Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-09-01 02:36 +0000
              Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth c186282 <c186282@nnada.net> - 2025-09-01 01:52 -0400
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth "Carlos E.R." <robin_listas@es.invalid> - 2025-09-01 11:26 +0200
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Peter Flass <Peter@Iron-Spring.com> - 2025-09-01 08:01 -0700
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth rbowman <bowman@montana.com> - 2025-09-01 18:12 +0000
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth "Carlos E.R." <robin_listas@es.invalid> - 2025-09-01 20:15 +0200
              Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth "Carlos E.R." <robin_listas@es.invalid> - 2025-09-01 11:20 +0200
        Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Johnny Billquist <bqt@softjar.se> - 2025-08-30 11:49 +0200
          Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth ted@loft.tnolan.com (Ted Nolan <tednolan>) - 2025-08-30 17:39 +0000
            Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Johnny Billquist <bqt@softjar.se> - 2025-08-31 12:40 +0200
              Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Peter Flass <Peter@Iron-Spring.com> - 2025-08-31 08:19 -0700
                Re: Unix on x86, Hmmm ... Downloaded Xenix - But It's *41* Floppies Worth Johnny Billquist <bqt@softjar.se> - 2025-08-31 20:10 +0200

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