Groups | Search | Server Info | Login | Register
Groups > alt.os.development > #18782
| From | John Ames <commodorejohn@gmail.com> |
|---|---|
| Newsgroups | alt.os.development |
| Subject | Re: z/PDOS-generic |
| Date | 2025-03-11 08:37 -0700 |
| Organization | A noiseless patient Spider |
| Message-ID | <20250311083745.000076a4@gmail.com> (permalink) |
| References | <v7bbdt$2fj5a$1@dont-email.me> <20250310130006.00000497@gmail.com> <vqnhhi$atq$1@reader1.panix.com> <20250310151114.000023e9@gmail.com> <vqnrjl$4a9$1@reader1.panix.com> |
On Mon, 10 Mar 2025 23:11:49 -0000 (UTC) cross@spitfire.i.gajendra.net (Dan Cross) wrote: > I already posted the definition I like to use, which came to me > via Mothy Roscoe, at ETH, but I'll post it again: > > He defines the operating system as, > That body of software that, > 1. Multiplexes the machine's hardware resources > 2. Abstracts the hardware platform > 3. Protects software principles from each other > (using the hardware) You surely did; however, that does not mean that anybody else is obligated to accept it. Specifically, let me ask: 1. Why must it multiplex anything, in a single-user system? Multi- tasking is certainly a nicety, but why should it be considered a necessary criterion for "real" status? 2. What is the minimum level of hardware abstraction, and why? MS-DOS does in fact abstract the details of, e.g., filesystem access, pipes, and to a lesser extent serial/parallel communications. You seem to be fixated on the fact that its ABI uses x86 interrupts rather than an alternative method; why is this important? 3. Again, in an 8086 environment this is *literally impossible.* There is no operating system for the IBM PC or XT that *can* implement any kind of protection. Additionally, in a single-user system, why is this a requirement rather than a nicety? > >MS-DOS very definitely takes control of the computer - it does not > >*hold onto it* very tightly, but there's no particular reason it > >should have to. > > Given the above definition, there's a very good reason: how does > it otherwise protect _itself_, as a software principle, from an > errant, let alone malicious, program? It doesn't, because it cannot. The 8086 offers absolutely no facility for protection, nor does the PC hardware implement any kind of bolt-on mechanism for this. That did not even become *possible* until the introduction of the PC/AT in 1984, three years after DOS was released, and that was limited by the infamously "brain-damaged" protected mode of the 286. > Also, a boot loader takes control of the computer, albeit > temporarily: is that also an operating system? Merely taking > control of the computer is insufficient. The OpenBoot PROM > monitor on a SPARCstation could be entered via a keyboard > shortcut, suspending Unix and the SPARC processor; was that an > "operating system"? In the strict sense, I don't see why not. A primitive one, granted, but if ROM BASIC counts as an operating system, OpenBoot certainly would.
Back to alt.os.development | Previous | Next — Previous in thread | Next in thread | Find similar
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
csiph-web