From: clemc@ccc.com (Clement T. Cole)
Subject: [TUHS] OS for IBM PC (was: Algol68 vs. C at Bell Labs)
Date: Mon, 4 Jul 2016 17:12:21 -0400 [thread overview]
Message-ID: <7A53ECB0-4C55-49F0-B785-CCB3BF7D0BFF@ccc.com> (raw)
In-Reply-To: <20160704181330.GM13274@mcvoy.com>
Thoth Thucks ....
Actually to give Mike Malcom created Thoth ney QNX was very slick. I agree with Larry. It was very impressive at the time. So between Thoth (which was Unix-similar) and Minix (which was V7 Unix API clone) I think it is safe to say there are reasonable existance proofs for saying V7 was quite possible on the 8086/8088 family.
Sent from my iPad
> On Jul 4, 2016, at 2:13 PM, Larry McVoy <lm at mcvoy.com> wrote:
>
> QNX, which wasn't Unix compat at the time but sorta close, in the mid
> 1980's was very very small and ran just fine on a 80286. If my memory
> serves me correctly I had 4-10 people logged into that box on terminals.
>
> QNX, at least until they put real posix conformance in it, was a really
> tiny micro kernel with the rest of the os in processes. It fit in a
> 4K instruction cache with room to spare.
>
> QNX, in my opinion, is the only really interesting and commercially
> proven microkernel.
>
>> On Mon, Jul 04, 2016 at 12:54:15PM -0400, Norman Wilson wrote:
>> Greg Lehey:
>>
>> And why? Yes, the 8088 was a reasonably fast processor, so fast that
>> they could slow it down a little so that they could use the same
>> crystal to create the clock both for the CPU and the USART. But the
>> base system had only 16 kB memory, only a little more than half the
>> size of the 6th Edition kernel. Even without the issue of disks
>> (which could potentially have been worked around) it really wasn't big
>> enough for a multiprogramming OS.
>>
>> =====
>>
>> Those who remember the earliest UNIX (even if few of us have
>> used it) might disagree with that. Neither the PDP-7 nor the
>> PDP-11/20 on which UNIX was born had memory management: a
>> context switch was a swap. That would have been pretty slow
>> on floppies, so perhaps it wouldn't have been saleable, but
>> it was certainly possible.
>>
>> In fact Heinz Lycklama revived the idea in the V6 era to
>> create LSX, a UNIX for the early LSI-11 which had no
>> memory management and a single ca. 300kiB floppy drive.
>> It had more memory than the 8088 system, though: 20kiW,
>> i.e. 40kiB. Even so, Lycklama did quite a bit of work to
>> squeeze the kernel down, reduce the number of processes
>> and context switches, and so on.
>>
>> Here's a link to one of his papers on the system:
>>
>> https://www.computer.org/csdl/proceedings/afips/1977/5085/00/50850237.pdf
>>
>> I suspect it would have been possible to make a XENIX
>> that would have worked on that hardware. Whether it
>> would have worked well enough to sell is another question.
>>
>> Norman Wilson
>> Toronto ON
>
> --
> ---
> Larry McVoy lm at mcvoy.com http://www.mcvoy.com/lm
next prev parent reply other threads:[~2016-07-04 21:12 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-04 16:54 Norman Wilson
2016-07-04 18:13 ` Larry McVoy
2016-07-04 21:12 ` Clement T. Cole [this message]
2016-07-07 2:20 ` [TUHS] Microkernels (was: OS for IBM PC (was: Algol68 vs. C at Bell Labs)) Greg 'groggy' Lehey
2016-07-07 10:51 ` John Cowan
2016-07-07 23:36 ` Greg 'groggy' Lehey
-- strict thread matches above, loose matches on Subject: below --
2016-06-30 13:22 [TUHS] Algol68 vs. C at Bell Labs Clem Cole
2016-06-30 14:05 ` Marc Rochkind
2016-06-30 15:32 ` Dan Cross
2016-06-30 15:49 ` Larry McVoy
2016-07-04 5:08 ` [TUHS] OS for IBM PC (was: Algol68 vs. C at Bell Labs) Greg 'groggy' Lehey
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