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Groups > alt.os.development > #18760
| From | cross@spitfire.i.gajendra.net (Dan Cross) |
|---|---|
| Newsgroups | alt.os.development |
| Subject | Re: z/PDOS-generic |
| Date | 2025-03-10 12:38 +0000 |
| Organization | PANIX Public Access Internet and UNIX, NYC |
| Message-ID | <vqmmf8$gqu$1@reader1.panix.com> (permalink) |
| References | <v7bbdt$2fj5a$1@dont-email.me> <87o6ybbeqw.fsf@example.com> <vqit96$1kh$1@reader1.panix.com> <HDizP.341661$eNx6.233542@fx14.iad> |
In article <HDizP.341661$eNx6.233542@fx14.iad>, Scott Lurndal <slp53@pacbell.net> wrote: >cross@spitfire.i.gajendra.net (Dan Cross) writes: >>In article <87o6ybbeqw.fsf@example.com>, >>Salvador Mirzo <smirzo@example.com> wrote: >>>scott@slp53.sl.home (Scott Lurndal) writes: >>>> MS-DOS is, was, and always will be a toy. It's not even >>>> a real operating system. >>> >>>And why is that? Is it mainly because it doesn't time-share the CPU? >> >>It depends on your definition of an operating system, I suppose. >>I like the definition Mothy Roscoe (ETH) used in his OSDI'21 >>keynote: >> >>The operating system is that body of software that: >>1. Multiplexes the machine's hardware resources >>2. Abstracts the hardware platform >>3. Protects software princples from each other >> (using the hardare) >> >>It's hard to see how MS-DOS fits that definition in a meaningful >>way. Does it multiplex the machine's hardware resources? Well, >>no; not really. While it does provide a primitive filesystem, >>and exposes some interface for memory management, it only lets >>one program run at a time, and that program doesn't have to use >>or honor DOS's filesystem or memory management stuff. > >To partially aleviate these defects, a concept called TSR (Terminate and >Stay Resident) was developed for MS-DOS. However, conflicts >between various TSRs were endemic and there was no hardware >protection between them or between them and the application >code. > >https://en.wikipedia.org/wiki/Terminate-and-stay-resident_program#Faults Oh gee, as a form of mental self-protection, I had blanked that madness out of my mind. What an awful interface. I do hand it to people who were writing DOS programs; without any real form or protection between programs, let along between DOS and programs, it's amazing that anything there worked at all. Still, lack of multiprogramming shows that they were targetting an audience that was pretty unsophisticated. I get that the hardware was limited, but Unix on the PDP-7 supported multiple users in 8KiW of 18-bit memory in 1969. A 16-bit system 12 years later could have supported a real OS, albeit without useful memory protection (CPU rings and the CPL didn't show up until the 80286). I suppose one could have played games with segmentation to isolate a small kernel; as I understand it, that was how the various Unix ports worked. It's weird to me how the 8086 included support for multiprocessing systems, but not a mode bit for a kernel. It's fun to speculate how the world could have been different: had Intel chosen the 68000 for the IBM PC, I imagine we could have had much more reasonable software rather quickly. The ripple effects of the legacy of DOS and the 8086 are unfortunate, at best. Oh well. - Dan C.
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z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2024-07-18 23:07 +0800
Re: z/PDOS-generic Grant Taylor <gtaylor@tnetconsulting.net> - 2024-07-18 22:40 -0500
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2024-07-19 18:43 +0800
Re: z/PDOS-generic scott@slp53.sl.home (Scott Lurndal) - 2024-07-19 16:18 +0000
Re: z/PDOS-generic BGB-Alt <bohannonindustriesllc@gmail.com> - 2024-07-19 17:12 -0500
Re: z/PDOS-generic scott@slp53.sl.home (Scott Lurndal) - 2024-07-19 23:21 +0000
Re: z/PDOS-generic cross@spitfire.i.gajendra.net (Dan Cross) - 2024-07-19 23:31 +0000
Re: z/PDOS-generic BGB <cr88192@gmail.com> - 2024-07-20 01:30 -0500
Re: z/PDOS-generic John Ames <commodorejohn@gmail.com> - 2024-07-22 07:51 -0700
Re: z/PDOS-generic cross@spitfire.i.gajendra.net (Dan Cross) - 2024-07-22 15:22 +0000
Re: z/PDOS-generic John Ames <commodorejohn@gmail.com> - 2024-07-22 09:07 -0700
Re: z/PDOS-generic cross@spitfire.i.gajendra.net (Dan Cross) - 2024-07-22 17:37 +0000
Re: z/PDOS-generic scott@slp53.sl.home (Scott Lurndal) - 2024-07-22 18:07 +0000
Re: z/PDOS-generic cross@spitfire.i.gajendra.net (Dan Cross) - 2024-07-22 19:38 +0000
Re: z/PDOS-generic John Ames <commodorejohn@gmail.com> - 2024-07-22 11:18 -0700
Re: z/PDOS-generic BGB <cr88192@gmail.com> - 2024-07-22 14:16 -0500
Re: z/PDOS-generic scott@slp53.sl.home (Scott Lurndal) - 2024-07-22 20:14 +0000
Re: z/PDOS-generic BGB <cr88192@gmail.com> - 2024-07-22 18:03 -0500
Re: z/PDOS-generic scott@slp53.sl.home (Scott Lurndal) - 2024-07-22 23:58 +0000
Re: z/PDOS-generic BGB <cr88192@gmail.com> - 2024-07-22 23:06 -0500
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2024-08-21 04:31 +0800
Re: z/PDOS-generic BGB <cr88192@gmail.com> - 2024-08-28 02:28 -0500
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2024-08-28 16:54 +0800
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2024-08-28 16:58 +0800
Re: z/PDOS-generic BGB <cr88192@gmail.com> - 2024-08-28 18:03 -0500
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2024-08-29 11:14 +0800
Re: z/PDOS-generic George Neuner <gneuner2@comcast.net> - 2024-08-30 06:49 -0400
Re: z/PDOS-generic George Neuner <gneuner2@comcast.net> - 2024-08-30 10:27 -0400
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2024-08-31 10:21 +0800
Re: z/PDOS-generic George Neuner <gneuner2@comcast.net> - 2024-08-31 15:30 -0400
Re: z/PDOS-generic cross@spitfire.i.gajendra.net (Dan Cross) - 2024-09-03 14:27 +0000
Re: z/PDOS-generic wolfgang kern <nowhere@never.at> - 2024-08-30 13:29 +0200
Re: z/PDOS-generic Waldek Hebisch <antispam@fricas.org> - 2024-09-03 23:38 +0000
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2024-09-06 07:46 +0800
Re: z/PDOS-generic J. Curtis <unknown@protocol.invalid> - 2024-09-06 20:08 +0100
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2024-09-07 08:12 +0800
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2025-01-22 17:34 +1100
Re: z/PDOS-generic J. Curtis <unknown@protocol.invalid> - 2024-07-20 00:02 +0100
Re: z/PDOS-generic Salvador Mirzo <smirzo@example.com> - 2025-03-08 14:42 -0300
Re: z/PDOS-generic cross@spitfire.i.gajendra.net (Dan Cross) - 2025-03-09 02:09 +0000
Re: z/PDOS-generic scott@slp53.sl.home (Scott Lurndal) - 2025-03-09 15:40 +0000
Re: z/PDOS-generic cross@spitfire.i.gajendra.net (Dan Cross) - 2025-03-10 12:38 +0000
Re: z/PDOS-generic scott@slp53.sl.home (Scott Lurndal) - 2025-03-10 14:49 +0000
Re: z/PDOS-generic cross@spitfire.i.gajendra.net (Dan Cross) - 2025-03-10 15:00 +0000
Re: z/PDOS-generic Salvador Mirzo <smirzo@example.com> - 2025-03-10 09:21 -0300
Re: z/PDOS-generic cross@spitfire.i.gajendra.net (Dan Cross) - 2025-03-10 13:50 +0000
Re: z/PDOS-generic Salvador Mirzo <smirzo@example.com> - 2025-03-10 14:10 -0300
Studying the system (was Re: z/PDOS-generic) cross@spitfire.i.gajendra.net (Dan Cross) - 2025-03-10 18:29 +0000
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2025-03-11 05:38 +1100
Re: z/PDOS-generic scott@slp53.sl.home (Scott Lurndal) - 2025-03-10 19:07 +0000
Re: z/PDOS-generic cross@spitfire.i.gajendra.net (Dan Cross) - 2025-03-10 19:09 +0000
Re: z/PDOS-generic John Ames <commodorejohn@gmail.com> - 2025-03-10 13:00 -0700
Re: z/PDOS-generic cross@spitfire.i.gajendra.net (Dan Cross) - 2025-03-10 20:20 +0000
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2025-03-11 07:59 +1100
Re: z/PDOS-generic John Ames <commodorejohn@gmail.com> - 2025-03-10 15:11 -0700
Re: z/PDOS-generic cross@spitfire.i.gajendra.net (Dan Cross) - 2025-03-10 23:11 +0000
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2025-03-11 10:51 +1100
Re: z/PDOS-generic John Ames <commodorejohn@gmail.com> - 2025-03-11 08:37 -0700
Re: z/PDOS-generic cross@spitfire.i.gajendra.net (Dan Cross) - 2025-03-11 17:28 +0000
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2025-03-12 05:40 +1100
Re: z/PDOS-generic John Ames <commodorejohn@gmail.com> - 2025-03-11 12:41 -0700
What is an operating system? (was Re: z/PDOS-generic) cross@spitfire.i.gajendra.net (Dan Cross) - 2025-03-11 21:00 +0000
Re: What is an operating system? (was Re: z/PDOS-generic) "Paul Edwards" <mutazilah@gmail.com> - 2025-03-12 17:30 +1100
Re: z/PDOS-generic John Ames <commodorejohn@gmail.com> - 2025-03-11 09:04 -0700
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2025-03-11 08:29 +1100
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2025-03-11 05:06 +1100
Re: z/PDOS-generic scott@slp53.sl.home (Scott Lurndal) - 2025-03-10 19:01 +0000
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2025-03-11 08:04 +1100
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2025-03-11 08:47 +1100
Re: z/PDOS-generic antispam@fricas.org (Waldek Hebisch) - 2025-03-11 18:15 +0000
Re: z/PDOS-generic cross@spitfire.i.gajendra.net (Dan Cross) - 2025-03-11 18:29 +0000
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2025-03-12 05:52 +1100
Re: z/PDOS-generic antispam@fricas.org (Waldek Hebisch) - 2025-03-11 23:05 +0000
Re: z/PDOS-generic cross@spitfire.i.gajendra.net (Dan Cross) - 2025-03-11 23:48 +0000
Re: z/PDOS-generic antispam@fricas.org (Waldek Hebisch) - 2025-03-12 02:23 +0000
Re: z/PDOS-generic cross@spitfire.i.gajendra.net (Dan Cross) - 2025-03-12 02:34 +0000
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2025-03-12 18:41 +1100
Re: z/PDOS-generic John Ames <commodorejohn@gmail.com> - 2024-07-19 09:35 -0700
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2024-08-21 04:20 +0800
Re: z/PDOS-generic John Ames <commodorejohn@gmail.com> - 2024-08-21 09:51 -0700
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2024-08-22 13:24 +0800
Re: z/PDOS-generic Grant Taylor <gtaylor@tnetconsulting.net> - 2024-07-19 19:46 -0500
Re: z/PDOS-generic "Paul Edwards" <mutazilah@gmail.com> - 2024-08-21 04:18 +0800
Re: z/PDOS-generic Salvador Mirzo <smirzo@example.com> - 2025-03-08 14:41 -0300
Re: z/PDOS-generic cross@spitfire.i.gajendra.net (Dan Cross) - 2025-03-09 01:58 +0000
Re: z/PDOS-generic Salvador Mirzo <smirzo@example.com> - 2025-03-10 09:31 -0300
Re: z/PDOS-generic cross@spitfire.i.gajendra.net (Dan Cross) - 2025-03-10 14:28 +0000
Re: z/PDOS-generic scott@slp53.sl.home (Scott Lurndal) - 2025-03-10 14:46 +0000
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