From: Warner Losh <imp@bsdimp.com>
To: Dr Iain Maoileoin <iain@csp-partnership.co.uk>
Cc: TUHS main list <tuhs@minnie.tuhs.org>
Subject: Re: [TUHS] Photos of University Computer Labs - now off topic
Date: Thu, 23 Dec 2021 10:02:40 -0600 [thread overview]
Message-ID: <CANCZdfrvbtasOXJfF6CD7EdvAQ49rCu16eT4koD+5kWrKxRgQg@mail.gmail.com> (raw)
In-Reply-To: <ca9d9c00-fd60-b8f9-c5b4-e00c7d7ad07c@csp-partnership.co.uk>
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On Thu, Dec 23, 2021, 8:54 AM Dr Iain Maoileoin <iain@csp-partnership.co.uk>
wrote:
> On 12/23/21 2:19 PM, Larry McVoy wrote:
>
> On Thu, Dec 23, 2021 at 01:05:55PM +0000, Michael Kj??rling wrote:
>
> On 22 Dec 2021 18:18 -0800, from lm@mcvoy.com (Larry McVoy):
>
> The CP/M machines bring back different memories, using that and BDS
> C because an 11/780 with 4MB of ram and 40 users meant each user was
> getting 1KB so it swapped and swapped and swapped.
>
> 4 MB RAM and 40 users works out to 100 KB of RAM per user for me. Even
> accounting for a large at the time OS it should be several tens of
> kilobytes per user on average for actual useful data. So, because
> there's probably some detail here that means you're right and I'm
> wrong, how do you arrive at the figure 1 KB of RAM per user in that
> scenario?
>
> Probably boomer doing math wrong.
>
> I might get flamed for this comment, but is a number divided by a number
> not arithmetic. I cant see any maths in there.
>
> In my support I point out that the "dc" manual page says
>
> dc is a reverse-polish desk calculator which supports unlimited precision arithmetic.
>
>
> In Scotland - at least years ago - arithmetic was an examinable subject at
> the lower grades (you also get a mathematics exam at the same grade).
>
> Arithmetic could not be taken past the basic level, mathematics could.
>
> Nowadays they have lumped arithmetic into maths (pronounced "maffs").
>
> Do other countries have this change in language?
>
> Sorry for the intrusion. It is Christmas with me (or is it "happy holiday"
> to be politically correct).
>
> You are right, I'm wrong. Though I
> will say that 100K/student was _painful_. Not enough to run make/cc in
> any reasonable time. About the only thing that worked was ^t (I think
> that was it) that showed you some basic info about performance.
>
> I had forgotten about control-t - does anything modern still do that
>
FreeBSD does. It's my biggest annoyance with Linux that it doesn't.
100k for a process that likely needed 500k to 1MB would indeed be swapping
its brains out. So while tha vax could do I/O 10 times faster than a Z80 of
the era and run maybe 5 times faster, all that was lost when you started
thrashing because you can't keep your working set in memory.
Warner
>
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next prev parent reply other threads:[~2021-12-23 16:03 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-22 15:11 [TUHS] Photos of University Computer Labs Alexander Jacocks via TUHS
2021-12-22 20:31 ` josh
2021-12-22 21:07 ` Rob Pike
2021-12-22 21:15 ` Rob Pike
2021-12-23 4:28 ` Warren Toomey
2021-12-23 4:31 ` Alexander Jacocks via TUHS
2021-12-23 4:45 ` Rob Pike
2021-12-22 21:14 ` Win Treese
2021-12-23 0:48 ` Adam Thornton
2021-12-23 1:30 ` Adam Sampson
2021-12-23 2:18 ` Larry McVoy
2021-12-23 13:05 ` Michael Kjörling
2021-12-23 14:19 ` Larry McVoy
2021-12-23 15:29 ` [TUHS] Photos of University Computer Labs - now off topic Dr Iain Maoileoin
2021-12-23 16:00 ` Larry McVoy
2021-12-23 16:28 ` Dr Iain Maoileoin
2021-12-23 16:35 ` Larry McVoy
2021-12-23 16:47 ` Dr Iain Maoileoin
2021-12-23 22:15 ` Steve Nickolas
2021-12-24 20:57 ` Derek Fawcus
2021-12-23 16:02 ` Warner Losh [this message]
2021-12-23 16:19 ` Larry McVoy
2021-12-23 22:13 ` Steve Nickolas
2021-12-24 3:48 ` Theodore Ts'o
2021-12-28 21:45 ` Greg A. Woods
2021-12-29 16:58 ` Theodore Ts'o
2022-01-09 19:04 ` Stuart Remphrey
2021-12-25 0:00 ` [TUHS] Photos of University Computer Labs Mike Markowski
2021-12-29 2:44 ` Alexander Jacocks via TUHS
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