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Groups > alt.folklore.computers > #220214 > unrolled thread

TOPS-20 Boot Camp for VMS Users 05-Mar-2022

Started by"Stephen M. Jones" <smj@ma.sdf.org>
First post2022-03-02 21:32 +0000
Last post2022-03-08 16:32 +0100
Articles 20 on this page of 93 — 23 participants

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Contents

  TOPS-20 Boot Camp for VMS Users 05-Mar-2022 "Stephen M. Jones" <smj@ma.sdf.org> - 2022-03-02 21:32 +0000
    Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 scott@slp53.sl.home (Scott Lurndal) - 2022-03-03 14:30 +0000
      Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Ahem A Rivet's Shot <steveo@eircom.net> - 2022-03-03 16:38 +0000
        Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 scott@slp53.sl.home (Scott Lurndal) - 2022-03-03 17:13 +0000
          Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Rich Alderson <news@alderson.users.panix.com> - 2022-03-03 15:33 -0500
            Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 scott@slp53.sl.home (Scott Lurndal) - 2022-03-03 21:55 +0000
              Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Peter Flass <peter_flass@yahoo.com> - 2022-03-04 12:06 -0700
                Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Paul Rubin <no.email@nospam.invalid> - 2022-03-04 13:23 -0800
                  Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Johnny Billquist <bqt@softjar.se> - 2022-03-06 17:29 +0100
                    Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Peter Flass <peter_flass@yahoo.com> - 2022-03-06 11:34 -0700
                      Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 scott@slp53.sl.home (Scott Lurndal) - 2022-03-06 19:40 +0000
                      Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Charles Richmond <codescott@aquaporin4.com> - 2022-12-23 11:49 -0600
                      Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Anne & Lynn Wheeler <lynn@garlic.com> - 2022-12-23 10:34 -1000
                        Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Ahem A Rivet's Shot <steveo@eircom.net> - 2022-12-23 21:42 +0000
                          Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Vir Campestris <vir.campestris@invalid.invalid> - 2022-12-24 11:54 +0000
                            Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 D.J. <chucktheouch@gmnol.com> - 2022-12-24 11:17 -0600
                              Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 D.J. <chucktheouch@gmnol.com> - 2022-12-24 18:01 -0600
                                Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Peter Flass <peter_flass@yahoo.com> - 2022-12-25 11:24 -0700
                              Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Anne & Lynn Wheeler <lynn@garlic.com> - 2022-12-25 09:12 -1000
                              Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Vir Campestris <vir.campestris@invalid.invalid> - 2022-12-30 17:06 +0000
                                Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2022-12-30 19:09 +0000
                                Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 D.J. <chucktheouch@gmnol.com> - 2022-12-30 16:11 -0600
                              Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Thomas Koenig <tkoenig@netcologne.de> - 2022-12-30 20:22 +0000
                                Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 D.J. <chucktheouch@gmnol.com> - 2022-12-30 16:12 -0600
                                Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2022-12-30 23:44 +0000
                        Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Anne & Lynn Wheeler <lynn@garlic.com> - 2022-12-23 12:18 -1000
                        Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2022-12-24 03:43 +0000
                          Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Anne & Lynn Wheeler <lynn@garlic.com> - 2022-12-24 07:55 -1000
                          Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Peter Flass <peter_flass@yahoo.com> - 2022-12-24 11:08 -0700
                            Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 scott@slp53.sl.home (Scott Lurndal) - 2022-12-24 18:36 +0000
                            Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2022-12-24 21:09 +0000
                            Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Anne & Lynn Wheeler <lynn@garlic.com> - 2022-12-24 14:03 -1000
                          Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Anne & Lynn Wheeler <lynn@garlic.com> - 2022-12-24 14:46 -1000
                    Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Paul Rubin <no.email@nospam.invalid> - 2022-03-06 11:17 -0800
                      Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Johnny Billquist <bqt@softjar.se> - 2022-03-07 17:53 +0100
                        Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Vir Campestris <vir.campestris@invalid.invalid> - 2022-03-07 22:02 +0000
                          Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Charles Richmond <codescott@aquaporin4.com> - 2022-12-23 11:55 -0600
                            Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Peter Flass <peter_flass@yahoo.com> - 2022-12-23 12:27 -0700
                    Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2022-03-07 03:11 +0000
                Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Quadibloc <jsavard@ecn.ab.ca> - 2022-12-30 13:57 -0800
                  Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Niklas Karlsson <nikke.karlsson@gmail.com> - 2022-12-30 22:11 +0000
                    Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2022-12-30 23:44 +0000
                      Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Niklas Karlsson <nikke.karlsson@gmail.com> - 2022-12-30 23:56 +0000
                        Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 cb@elaine.df.lth.se (Christian Brunschen) - 2022-12-31 09:02 +0000
                  Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Rich Alderson <news@alderson.users.panix.com> - 2022-12-30 20:44 -0500
                  Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Peter Flass <peter_flass@yahoo.com> - 2022-12-30 20:08 -0700
                    Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Quadibloc <jsavard@ecn.ab.ca> - 2022-12-31 00:25 -0800
                      Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Johnny Billquist <bqt@softjar.se> - 2022-12-31 13:39 +0100
            Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Bob Eager <news0009@eager.cx> - 2022-03-04 00:46 +0000
              Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 "Stephen M. Jones" <smj@ma.sdf.org> - 2022-03-04 18:49 +0000
                Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 drb@ihatespam.msu.edu (Dennis Boone) - 2022-03-04 14:55 -0600
                  Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 scott@slp53.sl.home (Scott Lurndal) - 2022-03-04 22:14 +0000
                    Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Bob Eager <news0009@eager.cx> - 2022-03-04 22:17 +0000
                      Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 David Lesher <wb8foz@panix.com> - 2022-03-06 04:35 +0000
                      Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Ahem A Rivet's Shot <steveo@eircom.net> - 2022-03-06 05:40 +0000
              Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Rich Alderson <news@alderson.users.panix.com> - 2022-03-04 22:46 -0500
            Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Johnny Billquist <bqt@softjar.se> - 2022-03-06 17:21 +0100
              Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Peter Flass <peter_flass@yahoo.com> - 2022-03-06 11:34 -0700
                Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Johnny Billquist <bqt@softjar.se> - 2022-03-07 17:42 +0100
              Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Rich Alderson <news@alderson.users.panix.com> - 2022-03-06 20:43 -0500
                Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 scott@slp53.sl.home (Scott Lurndal) - 2022-03-07 15:07 +0000
                  Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Johnny Billquist <bqt@softjar.se> - 2022-03-07 17:51 +0100
                    Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 scott@slp53.sl.home (Scott Lurndal) - 2022-03-07 17:07 +0000
                      Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Peter Flass <peter_flass@yahoo.com> - 2022-03-07 11:47 -0700
                        Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 scott@slp53.sl.home (Scott Lurndal) - 2022-03-07 19:19 +0000
                        Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Andreas Eder <a_eder_muc@web.de> - 2022-03-08 10:08 +0100
                          Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Peter Flass <peter_flass@yahoo.com> - 2022-03-08 07:49 -0700
                            Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2022-03-08 19:47 +0000
                              Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Bob Eager <news0009@eager.cx> - 2022-03-09 01:03 +0000
                      Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Johnny Billquist <bqt@softjar.se> - 2022-03-07 20:18 +0100
                        Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 scott@slp53.sl.home (Scott Lurndal) - 2022-03-07 19:37 +0000
                          Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Dan Espen <dan1espen@gmail.com> - 2022-03-07 14:53 -0500
                            Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 scott@slp53.sl.home (Scott Lurndal) - 2022-03-07 20:43 +0000
                        Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Ahem A Rivet's Shot <steveo@eircom.net> - 2022-03-07 19:52 +0000
                  Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Rich Alderson <news@alderson.users.panix.com> - 2022-03-07 17:18 -0500
                    Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 scott@slp53.sl.home (Scott Lurndal) - 2022-03-07 22:33 +0000
                      Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 scott@slp53.sl.home (Scott Lurndal) - 2022-03-07 22:58 +0000
                        Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Johnny Billquist <bqt@softjar.se> - 2022-03-08 00:06 +0100
                      Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Peter Flass <peter_flass@yahoo.com> - 2022-03-08 07:49 -0700
                        Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 scott@slp53.sl.home (Scott Lurndal) - 2022-03-08 15:22 +0000
                          Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Peter Flass <peter_flass@yahoo.com> - 2022-03-08 11:17 -0700
                        Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Vir Campestris <vir.campestris@invalid.invalid> - 2022-03-08 21:09 +0000
                          Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 scott@slp53.sl.home (Scott Lurndal) - 2022-03-08 21:33 +0000
                Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Johnny Billquist <bqt@softjar.se> - 2022-03-07 20:24 +0100
        Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Rich Alderson <news@alderson.users.panix.com> - 2022-03-03 15:24 -0500
          Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Ahem A Rivet's Shot <steveo@eircom.net> - 2022-03-03 21:06 +0000
            Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Rich Alderson <news@alderson.users.panix.com> - 2022-03-04 22:47 -0500
      Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Peter Flass <peter_flass@yahoo.com> - 2022-03-04 12:06 -0700
      Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 D.J. <chucktheouch@gmail.com> - 2022-03-07 10:48 -0600
        Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 scott@slp53.sl.home (Scott Lurndal) - 2022-03-07 17:03 +0000
          Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 D.J. <chucktheouch@gmail.com> - 2022-03-07 19:52 -0600
            Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Fred Smith <fred@thejanitor.corp> - 2022-03-08 04:13 +0000
              Re: TOPS-20 Boot Camp for VMS Users 05-Mar-2022 Johnny Billquist <bqt@softjar.se> - 2022-03-08 16:32 +0100

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#220260

Fromscott@slp53.sl.home (Scott Lurndal)
Date2022-03-07 15:07 +0000
Message-ID<CcpVJ.46114$mF2.31622@fx11.iad>
In reply to#220256
Rich Alderson <news@alderson.users.panix.com> writes:
>Johnny Billquist <bqt@softjar.se> writes:
>

>
>I do not know VMS (or RSTS/E or RSX) internals.  Is DCL a separate program,
>like the TOPS-20 EXEC?  Or an interaction with the monitor/kernel?

VMS is an odd beast in that respect.  The VAX had a four privilege
rings (aside: interestingly enough, the relatively recent ARMv8
architecture also has four privilege rings (with a fifth coming soon)).

The kernel ran in the most privileged ring, Kernel Mode.   RMS (mainly
derived from RSX-11, IIRC, and authored by Andy Goldstein (IIRC again))
ran in the next most privileged ring (Executive Mode).   The Command
Interpreter (DCL) ran in the next ring (Supervisor Mode), and user
applications ran in the least privileged ring (User Mode).

As with most[*] ring-based privilege architectures, ring switches were
expensive and I believe once they went to Alpha, that architecture was
pretty much dead.

>
>> EXEC is for most people a much nicer environment than DCL. Command name 
>> completion, filename completion, guide words, interactive help... It's 
>> just so much nicer than DCL.

I didn't miss any of those features during the four years (1979-1983) that
I was doing systems programming on a four-vax cluster (with MA-780!), but
then I had been using TSS8.24 prior to that :-).

[*] most non-risc-based architectures, anyway.   ARMv8 ring switches
    while not free, can be quite efficient - far different from Intel
    ring switches, for which three generations of ring-switch instructions
    were created over the decades to make them more efficient.

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#220263

FromJohnny Billquist <bqt@softjar.se>
Date2022-03-07 17:51 +0100
Message-ID<t05d76$k1t$1@news.misty.com>
In reply to#220260
On 2022-03-07 16:07, Scott Lurndal wrote:
> Rich Alderson <news@alderson.users.panix.com> writes:
>> Johnny Billquist <bqt@softjar.se> writes:
>>
> 
>>
>> I do not know VMS (or RSTS/E or RSX) internals.  Is DCL a separate program,
>> like the TOPS-20 EXEC?  Or an interaction with the monitor/kernel?
> 
> VMS is an odd beast in that respect.  The VAX had a four privilege
> rings (aside: interestingly enough, the relatively recent ARMv8
> architecture also has four privilege rings (with a fifth coming soon)).
> 
> The kernel ran in the most privileged ring, Kernel Mode.   RMS (mainly
> derived from RSX-11, IIRC, and authored by Andy Goldstein (IIRC again))
> ran in the next most privileged ring (Executive Mode).   The Command
> Interpreter (DCL) ran in the next ring (Supervisor Mode), and user
> applications ran in the least privileged ring (User Mode).
> 
> As with most[*] ring-based privilege architectures, ring switches were
> expensive and I believe once they went to Alpha, that architecture was
> pretty much dead.

People are always making the multiple processor modes a thing way bigger 
than it is.

To comment more towards what Rich was thinking/asking, DCL is not a 
normal user program. It is possible to have other "shells" than DCL, 
which would live at the same level as DCL, but that almost was 
non-existant in real life. People instead have shells as programs 
running while DCL is still lurking in the background.

So it's less flexible than in Unix or TOPS-20, where it's just a program 
like any other.

RSX is in a way maybe the most weird of them all. In the goal to 
minimize memory and process resources, there is usually no program 
associated with your terminal when you are at the DCL prompt. Instead, 
it's all the responsibility of the terminal driver. Only when you've 
completed a line and hit enter will DCL (or MCR) be started for you, to 
process the line you typed.

In VMS, DCL is there the whole time.

>>> EXEC is for most people a much nicer environment than DCL. Command name
>>> completion, filename completion, guide words, interactive help... It's
>>> just so much nicer than DCL.
> 
> I didn't miss any of those features during the four years (1979-1983) that
> I was doing systems programming on a four-vax cluster (with MA-780!), but
> then I had been using TSS8.24 prior to that :-).

It's one of those things where if you never used it, you don't 
understand how much it means, and how much you'll miss it if it goes away.

It's very similar to how you'll feel today if someone throws /bin/sh at 
you, and you are used to tcsh or bash. No filename completion, no line 
editing, no interactive information, no nothing. It's like going back to 
the dark ages.

And TOPS-20 EXEC is *better* than tcsh or bash...

   Johnny

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#220266

Fromscott@slp53.sl.home (Scott Lurndal)
Date2022-03-07 17:07 +0000
Message-ID<3ZqVJ.66921$4JN7.30690@fx05.iad>
In reply to#220263
Johnny Billquist <bqt@softjar.se> writes:
>On 2022-03-07 16:07, Scott Lurndal wrote:
>> Rich Alderson <news@alderson.users.panix.com> writes:
>>> Johnny Billquist <bqt@softjar.se> writes:
>>>

>
>It's very similar to how you'll feel today if someone throws /bin/sh at 
>you, and you are used to tcsh or bash. No filename completion, no line 
>editing, no interactive information, no nothing. It's like going back to 
>the dark ages.

For what it's worth, I've been using ksh since 1989 and while it supports
filename completion, I've never used it (since I use vi-style command
line editing, it takes more than just the tab key to invoke completion).

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#220267

FromPeter Flass <peter_flass@yahoo.com>
Date2022-03-07 11:47 -0700
Message-ID<1092765219.668371347.362378.peter_flass-yahoo.com@news.eternal-september.org>
In reply to#220266
Scott Lurndal <scott@slp53.sl.home> wrote:
> Johnny Billquist <bqt@softjar.se> writes:
>> On 2022-03-07 16:07, Scott Lurndal wrote:
>>> Rich Alderson <news@alderson.users.panix.com> writes:
>>>> Johnny Billquist <bqt@softjar.se> writes:
>>>> 
> 
>> 
>> It's very similar to how you'll feel today if someone throws /bin/sh at 
>> you, and you are used to tcsh or bash. No filename completion, no line 
>> editing, no interactive information, no nothing. It's like going back to 
>> the dark ages.
> 
> For what it's worth, I've been using ksh since 1989 and while it supports
> filename completion, I've never used it (since I use vi-style command
> line editing, it takes more than just the tab key to invoke completion).
> 

I’m always amazed when I try to use some piece of software I used to use
years ago how primitive it seems now. Back then non-ISPF TSO or DOS EDLIN
seemed like usable, if not much fun, pieces of software. Playing with old
systems like TSS or Multics it seems like my biggest problem is lack of a
decent editor.

-- 
Pete

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#220269

Fromscott@slp53.sl.home (Scott Lurndal)
Date2022-03-07 19:19 +0000
Message-ID<4VsVJ.65365$oF2.34230@fx10.iad>
In reply to#220267
Peter Flass <peter_flass@yahoo.com> writes:
>Scott Lurndal <scott@slp53.sl.home> wrote:
>> Johnny Billquist <bqt@softjar.se> writes:
>>> On 2022-03-07 16:07, Scott Lurndal wrote:
>>>> Rich Alderson <news@alderson.users.panix.com> writes:
>>>>> Johnny Billquist <bqt@softjar.se> writes:
>>>>> 
>> 
>>> 
>>> It's very similar to how you'll feel today if someone throws /bin/sh at 
>>> you, and you are used to tcsh or bash. No filename completion, no line 
>>> editing, no interactive information, no nothing. It's like going back to 
>>> the dark ages.
>> 
>> For what it's worth, I've been using ksh since 1989 and while it supports
>> filename completion, I've never used it (since I use vi-style command
>> line editing, it takes more than just the tab key to invoke completion).
>> 
>
>I’m always amazed when I try to use some piece of software I used to use
>years ago how primitive it seems now. Back then non-ISPF TSO or DOS EDLIN
>seemed like usable, if not much fun, pieces of software. Playing with old
>systems like TSS or Multics it seems like my biggest problem is lack of a
>decent editor.

Yeah. I occasionally fire up tss8.24 on simh just to recall the old days;
using PIP to copy files seems so 1974.   I also fire up the HP-3000 MPE
on simh as I used that after the PDP-8, but before the VAX.  Interactively,
it was better than tss8.24, but compared to DCL, the command language was
limited (no scripting capability, for example) - however, the concept of
PASS files was an interesting feature - during a compile-link-run job
the output of a step could be written to $NEWPASS and the next step would
read from $OLDPASS; a transient unnamed temporary disk file.

$ BASICCOMP FILE.BAS
$ PREP $OLDPASS, $NEWPASS
$ RUN $OLDPASS

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#220283

FromAndreas Eder <a_eder_muc@web.de>
Date2022-03-08 10:08 +0100
Message-ID<87fsnske0l.fsf@eder.anydns.info>
In reply to#220267
On Mo 07 Mär 2022 at 11:47, Peter Flass <peter_flass@yahoo.com> wrote:

> Scott Lurndal <scott@slp53.sl.home> wrote:
> I’m always amazed when I try to use some piece of software I used to use
> years ago how primitive it seems now. Back then non-ISPF TSO or DOS EDLIN
> seemed like usable, if not much fun, pieces of software. Playing with old
> systems like TSS or Multics it seems like my biggest problem is lack of a
> decent editor.

Well, on Multics you have Emacs!
That should be enough for everyone :-)

'Andreas

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#220285

FromPeter Flass <peter_flass@yahoo.com>
Date2022-03-08 07:49 -0700
Message-ID<102799188.668443547.470178.peter_flass-yahoo.com@news.eternal-september.org>
In reply to#220283
Andreas Eder <a_eder_muc@web.de> wrote:
> On Mo 07 Mär 2022 at 11:47, Peter Flass <peter_flass@yahoo.com> wrote:
> 
>> Scott Lurndal <scott@slp53.sl.home> wrote:
>> I’m always amazed when I try to use some piece of software I used to use
>> years ago how primitive it seems now. Back then non-ISPF TSO or DOS EDLIN
>> seemed like usable, if not much fun, pieces of software. Playing with old
>> systems like TSS or Multics it seems like my biggest problem is lack of a
>> decent editor.
> 
> Well, on Multics you have Emacs!
> That should be enough for everyone :-)

I’ve managed to get fifty years in without having to learn emacs. I don’t
want to have to start now.

-- 
Pete

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#220289

FromCharlie Gibbs <cgibbs@kltpzyxm.invalid>
Date2022-03-08 19:47 +0000
Message-ID<ZoOVJ.50486$mF2.29500@fx11.iad>
In reply to#220285
On 2022-03-08, Peter Flass <peter_flass@yahoo.com> wrote:

> Andreas Eder <a_eder_muc@web.de> wrote:
>
>> On Mo 07 Mär 2022 at 11:47, Peter Flass <peter_flass@yahoo.com> wrote:
>> 
>>> I’m always amazed when I try to use some piece of software I used to use
>>> years ago how primitive it seems now. Back then non-ISPF TSO or DOS EDLIN
>>> seemed like usable, if not much fun, pieces of software. Playing with old
>>> systems like TSS or Multics it seems like my biggest problem is lack of a
>>> decent editor.
>> 
>> Well, on Multics you have Emacs!
>> That should be enough for everyone :-)
>
> I’ve managed to get fifty years in without having to learn emacs.
> I don’t want to have to start now.

I took a look at emacs a couple of years ago.
I found its mindset to be too foreign for me,
e.g. in things like tab handling.

My fingers speak vi.  That's usually enough.

-- 
/~\  Charlie Gibbs                  |  Microsoft is a dictatorship.
\ /  <cgibbs@kltpzyxm.invalid>      |  Apple is a cult.
 X   I'm really at ac.dekanfrus     |  Linux is anarchy.
/ \  if you read it the right way.  |  Pick your poison.

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#220292

FromBob Eager <news0009@eager.cx>
Date2022-03-09 01:03 +0000
Message-ID<j8qcn1Fi99fU4@mid.individual.net>
In reply to#220289
On Tue, 08 Mar 2022 19:47:05 +0000, Charlie Gibbs wrote:

> I took a look at emacs a couple of years ago.
> I found its mindset to be too foreign for me,
> e.g. in things like tab handling.
> 
> My fingers speak vi.  That's usually enough.

I have exactly the opposite. I started UNIX in 1975, although vi took a 
while to appear. I continued to use 'ed' because my terminal was a bit 
basic.

Then I got a PC with a simplified emacs that was marketed as part of a 
'word processor'. My fingers know that (but I also use 'ed' in extremis, 
usually in single user mode on a basic console).



-- 
Using UNIX since v6 (1975)...

Use the BIG mirror service in the UK:
 http://www.mirrorservice.org

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#220268

FromJohnny Billquist <bqt@softjar.se>
Date2022-03-07 20:18 +0100
Message-ID<t05lq4$u25$1@news.misty.com>
In reply to#220266
On 2022-03-07 18:07, Scott Lurndal wrote:
> Johnny Billquist <bqt@softjar.se> writes:
>> On 2022-03-07 16:07, Scott Lurndal wrote:
>>> Rich Alderson <news@alderson.users.panix.com> writes:
>>>> Johnny Billquist <bqt@softjar.se> writes:
>>>>
> 
>>
>> It's very similar to how you'll feel today if someone throws /bin/sh at
>> you, and you are used to tcsh or bash. No filename completion, no line
>> editing, no interactive information, no nothing. It's like going back to
>> the dark ages.
> 
> For what it's worth, I've been using ksh since 1989 and while it supports
> filename completion, I've never used it (since I use vi-style command
> line editing, it takes more than just the tab key to invoke completion).

Never used ksh, but it still certainly sounds like miles from sh.

I don't expect people will really get involved in TOPS-20 EXEC now, but 
if you were to use it for a while, I think you'd start see my point. :-)

If you ever use Cisco gear, you might have gotten some taste of it as 
well...

   Johnny

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#220271

Fromscott@slp53.sl.home (Scott Lurndal)
Date2022-03-07 19:37 +0000
Message-ID<5atVJ.65997$oF2.42054@fx10.iad>
In reply to#220268
Johnny Billquist <bqt@softjar.se> writes:
>On 2022-03-07 18:07, Scott Lurndal wrote:
>> Johnny Billquist <bqt@softjar.se> writes:
>>> On 2022-03-07 16:07, Scott Lurndal wrote:
>>>> Rich Alderson <news@alderson.users.panix.com> writes:
>>>>> Johnny Billquist <bqt@softjar.se> writes:
>>>>>
>> 
>>>
>>> It's very similar to how you'll feel today if someone throws /bin/sh at
>>> you, and you are used to tcsh or bash. No filename completion, no line
>>> editing, no interactive information, no nothing. It's like going back to
>>> the dark ages.
>> 
>> For what it's worth, I've been using ksh since 1989 and while it supports
>> filename completion, I've never used it (since I use vi-style command
>> line editing, it takes more than just the tab key to invoke completion).
>
>Never used ksh, but it still certainly sounds like miles from sh.

Indeed, ksh is quite powerful - you can even access arbitrary shared
library functions linked in at runtime;  has associative arrays and
a host of other useful scripting features (ksh93).

>
>I don't expect people will really get involved in TOPS-20 EXEC now, but 
>if you were to use it for a while, I think you'd start see my point. :-)

I find most of those old command interpreters limited and unusable after
using the korn shell for so many years.   I could give TOPS-20 EXEC
a try on simh someday to see, but I don't expect to like it much;
I suppose I could try to port the COBOL startrek game to COBOL on
the PDP-10 someday when I have absolutely nothing else to do :-)

>
>If you ever use Cisco gear, you might have gotten some taste of it as 
>well...

I got an offer to join the IOS team (and an offer from NetApp at the
same time), but turned them down and went to SGI instead - both Cisco
and Netapp would have been financially more lucrative in the long run, sadly.

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#220272

FromDan Espen <dan1espen@gmail.com>
Date2022-03-07 14:53 -0500
Message-ID<t05nrt$8bs$1@dont-email.me>
In reply to#220271
scott@slp53.sl.home (Scott Lurndal) writes:

> Johnny Billquist <bqt@softjar.se> writes:
>>On 2022-03-07 18:07, Scott Lurndal wrote:
>>> Johnny Billquist <bqt@softjar.se> writes:
>>>> On 2022-03-07 16:07, Scott Lurndal wrote:
>>>>> Rich Alderson <news@alderson.users.panix.com> writes:
>>>>>> Johnny Billquist <bqt@softjar.se> writes:
>>>>>>
>>> 
>>>>
>>>> It's very similar to how you'll feel today if someone throws /bin/sh at
>>>> you, and you are used to tcsh or bash. No filename completion, no line
>>>> editing, no interactive information, no nothing. It's like going back to
>>>> the dark ages.
>>> 
>>> For what it's worth, I've been using ksh since 1989 and while it supports
>>> filename completion, I've never used it (since I use vi-style command
>>> line editing, it takes more than just the tab key to invoke completion).
>>
>>Never used ksh, but it still certainly sounds like miles from sh.
>
> Indeed, ksh is quite powerful - you can even access arbitrary shared
> library functions linked in at runtime;  has associative arrays and
> a host of other useful scripting features (ksh93).

ksh has lots of good stuff, but miles from sh doesn't seem right.
It's very much like sh to a casual user.

-- 
Dan Espen

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#220274

Fromscott@slp53.sl.home (Scott Lurndal)
Date2022-03-07 20:43 +0000
Message-ID<J7uVJ.104809$Gojc.84268@fx99.iad>
In reply to#220272
Dan Espen <dan1espen@gmail.com> writes:
>scott@slp53.sl.home (Scott Lurndal) writes:
>
>> Johnny Billquist <bqt@softjar.se> writes:
>>>On 2022-03-07 18:07, Scott Lurndal wrote:
>>>> Johnny Billquist <bqt@softjar.se> writes:
>>>>> On 2022-03-07 16:07, Scott Lurndal wrote:
>>>>>> Rich Alderson <news@alderson.users.panix.com> writes:
>>>>>>> Johnny Billquist <bqt@softjar.se> writes:
>>>>>>>
>>>> 
>>>>>
>>>>> It's very similar to how you'll feel today if someone throws /bin/sh at
>>>>> you, and you are used to tcsh or bash. No filename completion, no line
>>>>> editing, no interactive information, no nothing. It's like going back to
>>>>> the dark ages.
>>>> 
>>>> For what it's worth, I've been using ksh since 1989 and while it supports
>>>> filename completion, I've never used it (since I use vi-style command
>>>> line editing, it takes more than just the tab key to invoke completion).
>>>
>>>Never used ksh, but it still certainly sounds like miles from sh.
>>
>> Indeed, ksh is quite powerful - you can even access arbitrary shared
>> library functions linked in at runtime;  has associative arrays and
>> a host of other useful scripting features (ksh93).
>
>ksh has lots of good stuff, but miles from sh doesn't seem right.
>It's very much like sh to a casual user.

by design.

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#220273

FromAhem A Rivet's Shot <steveo@eircom.net>
Date2022-03-07 19:52 +0000
Message-ID<20220307195246.548e2294e2b12c3a7ee2deae@eircom.net>
In reply to#220268
On Mon, 7 Mar 2022 20:18:28 +0100
Johnny Billquist <bqt@softjar.se> wrote:

> On 2022-03-07 18:07, Scott Lurndal wrote:
> > Johnny Billquist <bqt@softjar.se> writes:
> >> On 2022-03-07 16:07, Scott Lurndal wrote:
> >>> Rich Alderson <news@alderson.users.panix.com> writes:
> >>>> Johnny Billquist <bqt@softjar.se> writes:
> >>>>
> > 
> >>
> >> It's very similar to how you'll feel today if someone throws /bin/sh at
> >> you, and you are used to tcsh or bash. No filename completion, no line
> >> editing, no interactive information, no nothing. It's like going back
> >> to the dark ages.
> > 
> > For what it's worth, I've been using ksh since 1989 and while it
> > supports filename completion, I've never used it (since I use vi-style
> > command line editing, it takes more than just the tab key to invoke
> > completion).
> 
> Never used ksh, but it still certainly sounds like miles from sh.

	It's surprisingly close - basically sh with history and filename
completion added, much of bash history manipulation comes from ksh the rest
from csh.

-- 
Steve O'Hara-Smith
Odds and Ends at http://www.sohara.org/

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#220276

FromRich Alderson <news@alderson.users.panix.com>
Date2022-03-07 17:18 -0500
Message-ID<mddee3d4db3.fsf@panix5.panix.com>
In reply to#220260
scott@slp53.sl.home (Scott Lurndal) writes:

> Rich Alderson <news@alderson.users.panix.com> writes:
>> Johnny Billquist <bqt@softjar.se> writes:

>> I do not know VMS (or RSTS/E or RSX) internals.  Is DCL a separate program,
>> like the TOPS-20 EXEC?  Or an interaction with the monitor/kernel?

> VMS is an odd beast in that respect.  The VAX had a four privilege
> rings (aside: interestingly enough, the relatively recent ARMv8
> architecture also has four privilege rings (with a fifth coming soon)).

> The kernel ran in the most privileged ring, Kernel Mode.   RMS (mainly
> derived from RSX-11, IIRC, and authored by Andy Goldstein (IIRC again))
> ran in the next most privileged ring (Executive Mode).   The Command
> Interpreter (DCL) ran in the next ring (Supervisor Mode), and user
> applications ran in the least privileged ring (User Mode).

Interestingly, the *2nd generation* PDP-10, the KI-10 processor, implemented a
4-level privilege model:  Kernel, Executive, Public, and User.  Tops-10 ran
mostly in Executive mode, with only some of the most sensitive routines done in
Kernel mode.  Public mode was a user-level mode (i.e., no privileged
instructions such as I/O operations) which allowed for system services similar
to dynamic libraries in modern Unix-style operating systems, but serving a
different purpose.  User mode was the bog standard mode for any program not
requiring elevated privileges.

(Public mode was used by the system services such as spoolers so that user
 programs did not need to use system calls to interact with unit record
 equipment.)

> As with most[*] ring-based privilege architectures, ring switches were
> expensive and I believe once they went to Alpha, that architecture was
> pretty much dead.

The KI model was not ring-based in the way that I understand rings (based on
early Multics writings, mostly); it was simply a matter of a couple of bits in
the process status.

-- 
Rich Alderson					  news@alderson.users.panix.com
      Audendum est, et veritas investiganda; quam etiamsi non assequamur,
	  omnino tamen proprius, quam nunc sumus, ad eam perveniemus.
									--Galen

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#220277

Fromscott@slp53.sl.home (Scott Lurndal)
Date2022-03-07 22:33 +0000
Message-ID<DKvVJ.164322$t2Bb.114365@fx98.iad>
In reply to#220276
Rich Alderson <news@alderson.users.panix.com> writes:
>scott@slp53.sl.home (Scott Lurndal) writes:
>
>> Rich Alderson <news@alderson.users.panix.com> writes:
>>> Johnny Billquist <bqt@softjar.se> writes:
>
>>> I do not know VMS (or RSTS/E or RSX) internals.  Is DCL a separate program,
>>> like the TOPS-20 EXEC?  Or an interaction with the monitor/kernel?
>
>> VMS is an odd beast in that respect.  The VAX had a four privilege
>> rings (aside: interestingly enough, the relatively recent ARMv8
>> architecture also has four privilege rings (with a fifth coming soon)).
>
>> The kernel ran in the most privileged ring, Kernel Mode.   RMS (mainly
>> derived from RSX-11, IIRC, and authored by Andy Goldstein (IIRC again))
>> ran in the next most privileged ring (Executive Mode).   The Command
>> Interpreter (DCL) ran in the next ring (Supervisor Mode), and user
>> applications ran in the least privileged ring (User Mode).
>
>Interestingly, the *2nd generation* PDP-10, the KI-10 processor, implemented a
>4-level privilege model:  Kernel, Executive, Public, and User.  Tops-10 ran
>mostly in Executive mode, with only some of the most sensitive routines done in
>Kernel mode.  Public mode was a user-level mode (i.e., no privileged
>instructions such as I/O operations) which allowed for system services similar
>to dynamic libraries in modern Unix-style operating systems, but serving a
>different purpose.  User mode was the bog standard mode for any program not
>requiring elevated privileges.
>
>(Public mode was used by the system services such as spoolers so that user
> programs did not need to use system calls to interact with unit record
> equipment.)
>
>> As with most[*] ring-based privilege architectures, ring switches were
>> expensive and I believe once they went to Alpha, that architecture was
>> pretty much dead.
>
>The KI model was not ring-based in the way that I understand rings (based on
>early Multics writings, mostly); it was simply a matter of a couple of bits in
>the process status.

It's changing between rings that is the primary issue as that often
includes a change in the memory context (e.g. x86 segment, active page
table) resulting in a performance hit.   E.g. UUO's/system calls.

[toc] | [prev] | [next] | [standalone]


#220278

Fromscott@slp53.sl.home (Scott Lurndal)
Date2022-03-07 22:58 +0000
Message-ID<c6wVJ.106047$aT3.10944@fx09.iad>
In reply to#220277
scott@slp53.sl.home (Scott Lurndal) writes:
>Rich Alderson <news@alderson.users.panix.com> writes:
>>scott@slp53.sl.home (Scott Lurndal) writes:
>>
>>> Rich Alderson <news@alderson.users.panix.com> writes:
>>>> Johnny Billquist <bqt@softjar.se> writes:
>>
>>>> I do not know VMS (or RSTS/E or RSX) internals.  Is DCL a separate program,
>>>> like the TOPS-20 EXEC?  Or an interaction with the monitor/kernel?
>>
>>> VMS is an odd beast in that respect.  The VAX had a four privilege
>>> rings (aside: interestingly enough, the relatively recent ARMv8
>>> architecture also has four privilege rings (with a fifth coming soon)).
>>
>>> The kernel ran in the most privileged ring, Kernel Mode.   RMS (mainly
>>> derived from RSX-11, IIRC, and authored by Andy Goldstein (IIRC again))
>>> ran in the next most privileged ring (Executive Mode).   The Command
>>> Interpreter (DCL) ran in the next ring (Supervisor Mode), and user
>>> applications ran in the least privileged ring (User Mode).
>>
>>Interestingly, the *2nd generation* PDP-10, the KI-10 processor, implemented a
>>4-level privilege model:  Kernel, Executive, Public, and User.  Tops-10 ran
>>mostly in Executive mode, with only some of the most sensitive routines done in
>>Kernel mode.  Public mode was a user-level mode (i.e., no privileged
>>instructions such as I/O operations) which allowed for system services similar
>>to dynamic libraries in modern Unix-style operating systems, but serving a
>>different purpose.  User mode was the bog standard mode for any program not
>>requiring elevated privileges.
>>
>>(Public mode was used by the system services such as spoolers so that user
>> programs did not need to use system calls to interact with unit record
>> equipment.)
>>
>>> As with most[*] ring-based privilege architectures, ring switches were
>>> expensive and I believe once they went to Alpha, that architecture was
>>> pretty much dead.
>>
>>The KI model was not ring-based in the way that I understand rings (based on
>>early Multics writings, mostly); it was simply a matter of a couple of bits in
>>the process status.
>
>It's changing between rings that is the primary issue as that often
>includes a change in the memory context (e.g. x86 segment, active page
>table) resulting in a performance hit.   E.g. UUO's/system calls.

What really killed it on the VAX was multiple ring changes for many
operations (file operations executed in executive mode, and they
called kernel mode facilities like $QIO/$QIOW).   On the other hand,
user mode could make requests to DCL with a change mode to supervisor
call.

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#220279

FromJohnny Billquist <bqt@softjar.se>
Date2022-03-08 00:06 +0100
Message-ID<t06367$ep9$1@news.misty.com>
In reply to#220278
On 2022-03-07 23:58, Scott Lurndal wrote:
> scott@slp53.sl.home (Scott Lurndal) writes:
>> It's changing between rings that is the primary issue as that often
>> includes a change in the memory context (e.g. x86 segment, active page
>> table) resulting in a performance hit.   E.g. UUO's/system calls.
> 
> What really killed it on the VAX was multiple ring changes for many
> operations (file operations executed in executive mode, and they
> called kernel mode facilities like $QIO/$QIOW).   On the other hand,
> user mode could make requests to DCL with a change mode to supervisor
> call.

What do you mean "killed it on the VAX"? Changing mode means trapping to 
the OS. Doing a system call means trapping to the OS. Is a change mode 
any more costly than any system call? No.

Are you claiming there is some extra performance penalty here?

You could argue that the changing of modes carried a performance 
benefit, since it meant you did not need to switch context to another 
process, and you did not need to flush TLBs and so on, since the memory 
mapping is unchanged. Changing modes effectively just changed what parts 
of memory was accessible, apart from kernel mode which allowed some 
instructions not allowed otherwise.
And that is also why implementing the whole thing on a processor with 
fewer modes isn't really a big deal. It's just a question of what your 
page table looks like. And that can obviously be changed whenever you 
trap into the OS anyway.

   Johnny

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#220284

FromPeter Flass <peter_flass@yahoo.com>
Date2022-03-08 07:49 -0700
Message-ID<157167114.668443252.099266.peter_flass-yahoo.com@news.eternal-september.org>
In reply to#220277
Scott Lurndal <scott@slp53.sl.home> wrote:
> Rich Alderson <news@alderson.users.panix.com> writes:
>> scott@slp53.sl.home (Scott Lurndal) writes:
>> 
>>> Rich Alderson <news@alderson.users.panix.com> writes:
>>>> Johnny Billquist <bqt@softjar.se> writes:
>> 
>>>> I do not know VMS (or RSTS/E or RSX) internals.  Is DCL a separate program,
>>>> like the TOPS-20 EXEC?  Or an interaction with the monitor/kernel?
>> 
>>> VMS is an odd beast in that respect.  The VAX had a four privilege
>>> rings (aside: interestingly enough, the relatively recent ARMv8
>>> architecture also has four privilege rings (with a fifth coming soon)).
>> 
>>> The kernel ran in the most privileged ring, Kernel Mode.   RMS (mainly
>>> derived from RSX-11, IIRC, and authored by Andy Goldstein (IIRC again))
>>> ran in the next most privileged ring (Executive Mode).   The Command
>>> Interpreter (DCL) ran in the next ring (Supervisor Mode), and user
>>> applications ran in the least privileged ring (User Mode).
>> 
>> Interestingly, the *2nd generation* PDP-10, the KI-10 processor, implemented a
>> 4-level privilege model:  Kernel, Executive, Public, and User.  Tops-10 ran
>> mostly in Executive mode, with only some of the most sensitive routines done in
>> Kernel mode.  Public mode was a user-level mode (i.e., no privileged
>> instructions such as I/O operations) which allowed for system services similar
>> to dynamic libraries in modern Unix-style operating systems, but serving a
>> different purpose.  User mode was the bog standard mode for any program not
>> requiring elevated privileges.
>> 
>> (Public mode was used by the system services such as spoolers so that user
>> programs did not need to use system calls to interact with unit record
>> equipment.)
>> 
>>> As with most[*] ring-based privilege architectures, ring switches were
>>> expensive and I believe once they went to Alpha, that architecture was
>>> pretty much dead.
>> 
>> The KI model was not ring-based in the way that I understand rings (based on
>> early Multics writings, mostly); it was simply a matter of a couple of bits in
>> the process status.
> 
> It's changing between rings that is the primary issue as that often
> includes a change in the memory context (e.g. x86 segment, active page
> table) resulting in a performance hit.   E.g. UUO's/system calls.
> 

Some systems (Sigma) had different register sets for different processor
modes. Memory is cheap these days, why not different caches?

-- 
Pete

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#220286

Fromscott@slp53.sl.home (Scott Lurndal)
Date2022-03-08 15:22 +0000
Message-ID<ZwKVJ.50238$mF2.40615@fx11.iad>
In reply to#220284
Peter Flass <peter_flass@yahoo.com> writes:
>Scott Lurndal <scott@slp53.sl.home> wrote:
>> Rich Alderson <news@alderson.users.panix.com> writes:
>>> scott@slp53.sl.home (Scott Lurndal) writes:
>>> 
>>>> Rich Alderson <news@alderson.users.panix.com> writes:
>>>>> Johnny Billquist <bqt@softjar.se> writes:
>>> 
>>>>> I do not know VMS (or RSTS/E or RSX) internals.  Is DCL a separate program,
>>>>> like the TOPS-20 EXEC?  Or an interaction with the monitor/kernel?
>>> 
>>>> VMS is an odd beast in that respect.  The VAX had a four privilege
>>>> rings (aside: interestingly enough, the relatively recent ARMv8
>>>> architecture also has four privilege rings (with a fifth coming soon)).
>>> 
>>>> The kernel ran in the most privileged ring, Kernel Mode.   RMS (mainly
>>>> derived from RSX-11, IIRC, and authored by Andy Goldstein (IIRC again))
>>>> ran in the next most privileged ring (Executive Mode).   The Command
>>>> Interpreter (DCL) ran in the next ring (Supervisor Mode), and user
>>>> applications ran in the least privileged ring (User Mode).
>>> 
>>> Interestingly, the *2nd generation* PDP-10, the KI-10 processor, implemented a
>>> 4-level privilege model:  Kernel, Executive, Public, and User.  Tops-10 ran
>>> mostly in Executive mode, with only some of the most sensitive routines done in
>>> Kernel mode.  Public mode was a user-level mode (i.e., no privileged
>>> instructions such as I/O operations) which allowed for system services similar
>>> to dynamic libraries in modern Unix-style operating systems, but serving a
>>> different purpose.  User mode was the bog standard mode for any program not
>>> requiring elevated privileges.
>>> 
>>> (Public mode was used by the system services such as spoolers so that user
>>> programs did not need to use system calls to interact with unit record
>>> equipment.)
>>> 
>>>> As with most[*] ring-based privilege architectures, ring switches were
>>>> expensive and I believe once they went to Alpha, that architecture was
>>>> pretty much dead.
>>> 
>>> The KI model was not ring-based in the way that I understand rings (based on
>>> early Multics writings, mostly); it was simply a matter of a couple of bits in
>>> the process status.
>> 
>> It's changing between rings that is the primary issue as that often
>> includes a change in the memory context (e.g. x86 segment, active page
>> table) resulting in a performance hit.   E.g. UUO's/system calls.
>> 
>
>Some systems (Sigma) had different register sets for different processor
>modes. Memory is cheap these days, why not different caches?

Indeed, it's difficult to compare systems designed 40 to 50 years ago
with modern processors.

But even today, nobody uses more than two of the four rings on Intel
processors.  (well, technically, one can consider VM-X/SVM a ring,
and SMM mode can also be considered a ring, and in both cases,
crossing the ring boundary isn't cheap - see VMEXIT).

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