Re: Hmmm ... Downloaded Xenix - But It's 41 Floppies Worth

From	John Ames <commodorejohn@gmail.com>
Newsgroups	comp.os.linux.misc, alt.folklore.computers
Subject	Re: Hmmm ... Downloaded Xenix - But It's 41 Floppies Worth
Date	2025-08-26 08:31 -0700
Organization	A noiseless patient Spider
Message-ID	<20250826083118.00001403@gmail.com> (permalink)
References	(2 earlier) <aZ6cnU18-N5ONOX1nZ2dnZfqn_sAAAAA@giganews.com> <sm0cy9wllph.fsf@lakka.kapsi.fi> <105fgk4$2ka5f$1@dont-email.me> <20250721093237.0000674f@gmail.com> <108k7rn$e12$4@news.misty.com>

Cross-posted to 2 groups.

Show all headers | View raw

On Tue, 26 Aug 2025 14:04:07 +0200
Johnny Billquist <bqt@softjar.se> wrote:

> > Hmm, that's an interesting question, actually - the Bell Labs -11
> > was an 11/45, which was much faster than the original -11s, while
> > the IBM PC was really a bit of a dog thanks to having a 16-bit
> > architecture on an 8-bit bus and the generally poor performance
> > characteristics of the first-generation x86 CPUs. It'd be neat to
> > do a head-to-head shootout. I don't know if it's recorded whether
> > the Bell Labs -11 was core or semiconductor memory (980 vs. 450 ns
> > cycle time;) the PC at 4.77 MHz would have a cycle time of around
> > 209 ns, but with the aforementioned 8-bit bus. As a naive
> > approximation, that might put them anywhere from comparable to
> > around twice the memory bandwidth for the PC...but then the 8088's
> > instruction times are kinda abysmal even on top of that. Definitely
> > makes one curious...  
> 
> 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, and that really trips the whole thing over when comparing.
> (I'm not sure I would even say the x86 have anything resembling a
> proper MMU... Not before the 80386 anyway, which was not in a PC or
> PC/XT.)

The 286 had a proper MMU, but not (AFAIUI) a terribly performant one.
I've never heard of an add-on MMU for the 8086, but I admit I've never
looked. In any case, I realize now that my napkin math was way off; the
8086/88 can only perform a memory access every fourth cycle, so the
PC's approximate "cycle time" by comparison would be more like ~836 ns,
barely faster than core even *before* you factor in the 8-bit bottle-
neck or DRAM refresh. Ye gods, what a *dog.*

Back to comp.os.linux.misc | Previous | Next — Previous in thread | Next in thread | Find similar

Thread

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 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 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 "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 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 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 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

csiph-web