From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, HTML_MESSAGE,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 25498 invoked from network); 23 Dec 2021 16:03:09 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 23 Dec 2021 16:03:09 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 0F1FB9CEB9; Fri, 24 Dec 2021 02:03:09 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 773869CC2E; Fri, 24 Dec 2021 02:02:55 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=pass (2048-bit key; unprotected) header.d=bsdimp-com.20210112.gappssmtp.com header.i=@bsdimp-com.20210112.gappssmtp.com header.b="O1wt5KSt"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 2E10A9CC2E; Fri, 24 Dec 2021 02:02:54 +1000 (AEST) Received: from mail-ua1-f43.google.com (mail-ua1-f43.google.com [209.85.222.43]) by minnie.tuhs.org (Postfix) with ESMTPS id 5EC8B9CC00 for ; Fri, 24 Dec 2021 02:02:53 +1000 (AEST) Received: by mail-ua1-f43.google.com with SMTP id t13so10698239uad.9 for ; Thu, 23 Dec 2021 08:02:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bsdimp-com.20210112.gappssmtp.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=RpyDMTb2cGjUmw8Isbi4bqEpLKVn25ugzYSJyCArq9A=; b=O1wt5KStuzSKWMg4QVZvx3RgBiemni/HwqpFfUseIcEShLa2MAWR3O18aJ6bVE5Tg3 HDNYKI6fwVfCeLftMy+Fe354IEsyf3O2hbugHAF5ydUEut2aV8vhEpDUhhXT+f84Gatf 9QbaN5yQBNv7xmVHKx/qZ2lHODyK3A+cs2s/lTdwZOnH0EAIm9f00lQt/xziVVLS8SVu RQwoqVPbcJYPgbPMRSn73c+QplaiMxhrCpBRrBV5Y4wSwPnB3ea1oiU2zWZQv4au15Wz XG+lZ/vhlNAZmjXB+NkEEB6C2znO5QV6sHusm6w5VrQxEOSt1w4QvJ6Cd5SJTKSa1xzJ t0qA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=RpyDMTb2cGjUmw8Isbi4bqEpLKVn25ugzYSJyCArq9A=; b=bd9YXXCZJr9WevH0bxR379O/Fz89E6sEQ7/JxEmy5I+gv29bP56oUT6aWHi1Vad0KQ eb0C4mjic1JIF+WZvnXhwmZVuUiTnkL7PcJFrJSvkfMom156mUNr2aOgEZJJ5OMDc44p XwiOAn5tIACcukvDdAo+mWYNBFjtQfkqia+HsycAe+Bk3+QCfuUNboPW3n/wpHN9SiIb Rgy94ernE7U7VyyrmBKj8pXJi2fmQs+Z0Rg0Avr6m65f7LlQTX6Rx9wvLqsm6snTdVK1 owOw19eTq2MG+86m1GvCMgWMoqvpeSe037l51ZAjiWKnX/wXDOm7BgOsNkeDqVjs8WEC ePjw== X-Gm-Message-State: AOAM533czJ1p5i4/N/a1+FpaoMHAUsiYbSce1hYUrjWrMhXafQwJMUVW S/lShCyXa+k/Rbt5qhLDsbPWn8O1j2RwOEuUtjZdegbyuzc= X-Google-Smtp-Source: ABdhPJxJvUiVShnE8qaIiZko+nfND5dwqkeiXzDur/0cbsipX5F29MngJZ+W5Xxjr547+oDHDM4n9orjMTI6ZyiOZas= X-Received: by 2002:a05:6102:ec2:: with SMTP id m2mr1012972vst.6.1640275372260; Thu, 23 Dec 2021 08:02:52 -0800 (PST) MIME-Version: 1.0 References: <818A6F70-D117-471A-9E08-E37B34F8FAE0@mac.com> <20211223021805.GK24180@mcvoy.com> <20211223141958.GR24180@mcvoy.com> In-Reply-To: From: Warner Losh Date: Thu, 23 Dec 2021 10:02:40 -0600 Message-ID: To: Dr Iain Maoileoin Content-Type: multipart/alternative; boundary="000000000000e5d2c905d3d25efa" Subject: Re: [TUHS] Photos of University Computer Labs - now off topic X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: TUHS main list Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" --000000000000e5d2c905d3d25efa Content-Type: text/plain; charset="UTF-8" On Thu, Dec 23, 2021, 8:54 AM Dr Iain Maoileoin 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 > --000000000000e5d2c905d3d25efa Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


On Thu, Dec 23, 2021, 8:54 AM Dr Iain Maoileoin <iain@csp-partnership.co.uk&= gt; wrote:
=20 =20 =20
On 12/23/21 2:19 PM, Larry McVoy wrote:
On Thu, Dec 23, 2021 at 01:05:55PM +0000, Michael Kj??rling wrot=
e:

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.=C2=A0 I cant see any maths in there.

In my support I point out that the "dc" manual page says 

=C2=A0dc=C2=A0 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 "hap= py 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

F= reeBSD does. It's my biggest annoyance with Linux that it doesn't.<= /div>

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.=C2=A0

Warner
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