[HN Gopher] Myth: Windows 3.1 was just a shell on top of DOS
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Myth: Windows 3.1 was just a shell on top of DOS
Author : CA0DA
Score : 19 points
Date : 2023-05-22 14:47 UTC (8 hours ago)
(HTM) web link (lunduke.locals.com)
(TXT) w3m dump (lunduke.locals.com)
| piperswe wrote:
| Windows 3.x and 9x are "shells on top of DOS" the same way that
| Linux can be a "shell on top of DOS":
| https://github.com/haileys/doslinux
| frank_bb wrote:
| [dead]
| musicale wrote:
| > Win386 ran individual "V8086" processes -- which was a key
| feature of the Intel 386 processor running in Protected Mode --
| in a completely preemptive multitasking way.
|
| What about Win286/running Windows 3.1 on an 80286?
| Dwedit wrote:
| What about Windows running in Real Mode or Standard Mode?
| JoeAltmaier wrote:
| DOS provided a tiny fraction of what Windows provided?
|
| A full kernel acts as gatekeeper to system resources. While DOS
| provided access to some resources, it was single-process and so
| had no gatekeeping. No concept of different pools of resources,
| different lifetimes of activity. No comprehensive cleanup.
|
| Half of a kernel (or more) is taking things from one list and
| putting them on another list, so when something exits or dies or
| faults, it can release resources that were allocated to the dying
| thing.
|
| The hardware access was the lowest, simplest part of that. And
| DOS used the BIOS anyway, for half of what it did (floppy drivers
| etc). Which meant it had not a chance in hell of performing well
| (executing out of ROM or whatever).
| musicale wrote:
| > it had not a chance in hell of performing well (executing out
| of ROM or whatever)
|
| If CP/M-86 performed well, why wouldn't DOS? They're very
| similar.
|
| Wouldn't the "shadow RAM" technique of copying the ROM BIOS
| into RAM solve any ROM slowdown issues?
| JoeAltmaier wrote:
| Sure. But add to that, they were crappy drivers. Minimal
| things just to ship the product. No support for thread-safe
| or isolation or anything. In fact, they just looped on i/o
| ports waiting for device completion - no dma, no interrupts,
| nothing.
|
| Enough to boot. But worthless for any real OS.
| Aleklart wrote:
| It was not just a shell, but all other stuff is presented like
| microsoft sales memo. It had basic supervisor code that used
| intel v86 in protected mode and you can hang whole system with
| single call anytime. Guess what else can do it - Novell DOS 7.
| Win32s was much more of OS than windows 3.1
| stuaxo wrote:
| I wonder if anyone has managed to run windows apps in seperate
| vms just like the dos apps were (could you even start Windows in
| standard mode in one somehow)
| musicale wrote:
| In spite of Microsoft's best efforts, Windows 3.1 ran fine on top
| of DR-DOS or Novell DOS.
| https443 wrote:
| I always thought this was true.
| parl_match wrote:
| MS-DOS was not really what people would today consider to be a
| "true" kernel, as it didn't implement any sort of access
| controls, boundaries, or other process management
| functionality. It was more of a set of shared libraries, and
| also included some standards such as a file system, and program
| loader format.
|
| Even Windows 1.0, which more directly sat on top of MS-DOS, had
| to implement considerable amounts of functionality that would
| be considered more of a kernel than what MS-DOS offered.
| troad wrote:
| This is a fun little bite-sized post, but I wish it tackled more
| of the nitty-gritty.
|
| Does anyone know of any write-ups on the architecture of
| early-90s Windows that are more in depth, now that this has whet
| my appetite? (Or other OSes of the era, come to think of it?)
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(page generated 2023-05-22 23:01 UTC)