From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: tuhs-bounces@minnie.tuhs.org X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.4 required=5.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,HTML_FONT_LOW_CONTRAST,HTML_MESSAGE, MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE,T_DKIM_INVALID autolearn=ham autolearn_force=no version=3.4.1 Received: from minnie.tuhs.org (minnie.tuhs.org [45.79.103.53]) by inbox.vuxu.org (OpenSMTPD) with ESMTP id b9d494b1 for ; Tue, 19 Jun 2018 13:54:03 +0000 (UTC) Received: by minnie.tuhs.org (Postfix, from userid 112) id 874F6A1A03; Tue, 19 Jun 2018 23:54:02 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 9C9B0A19D5; Tue, 19 Jun 2018 23:53:42 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b=r/K92LDV; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 4A0C1A19D5; Tue, 19 Jun 2018 23:53:40 +1000 (AEST) Received: from mail-wm0-f44.google.com (mail-wm0-f44.google.com [74.125.82.44]) by minnie.tuhs.org (Postfix) with ESMTPS id B8B39A19D4 for ; Tue, 19 Jun 2018 23:53:38 +1000 (AEST) Received: by mail-wm0-f44.google.com with SMTP id p11-v6so591243wmc.4 for ; Tue, 19 Jun 2018 06:53:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=AtzJXX8B5CJIYfexQk5H4r5twYq0mvCCH4FezcQJCpg=; b=r/K92LDVdwLMXR39rP3hxg3NsZBtaC9ekZmxlQzZBXCDKaRBFhDxxGtPtdIpgcAZPe 4Erp+KONv1ql0kLEItFDX4VngFbYXqFw70U0Q2GnfXRAU0PatoxjPdn4AbuioI09TLs6 M+faHJX/6wvGxgOzWAl2udeNO7v1LBJ874X2hPCnkhdhZ4/ROYWjuzleZQsiGLNjjxCR kBsBCBrwFCgsvZtNi5Wm8HRbOIh3K/EC/caO9vw2lVJ3vRhBDohH/UbvZfVt1xsnlwEg oLQbv8eM5AaGpr4cTUC5tkkOjqx3udFdjt0Bg8l/+GenlZdQvBIpmw5A4FYcIPJz5nB9 s0RQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=AtzJXX8B5CJIYfexQk5H4r5twYq0mvCCH4FezcQJCpg=; b=CvV4Rf2q71HXN3TZ9BvTGBatFrCvIRHld11J/aTUNJ85E8bS4mD2V5h1dxd21wUcYD f0IMshr75KV6HCueUSJrNSHeX4zushwlUYOEhVnR3f/2iXX/r4kg0GVhUENzI7YIWcMR 1QWjEhmd3dxXe5g2bj0MdUWiXNCU4Qgxn7sbaPCOv7RwvjzHggy5vP+2EDippUAbYMQc 9ucLmQGMji2A1pNZ08njDmTIxBnUZbPXiKbNrcpM3sgFwN59xq5ijJ9eboaJEWDiffVt Yj9QJkasb6yFCaPqczoZk6j8btZOidpAaemSvlsrV2EqXmEglJiGqobp/BtvVxLxxFUQ J/jg== X-Gm-Message-State: APt69E2m03++AbQjI6tJWjEbcbVYZvwQEDA5+YuerxyP59jNaVwTjxYS cf2+yFjCVseUP0kGHkbQ2fakVLKlVkIkaJb3qS8= X-Google-Smtp-Source: ADUXVKIemBcHKAWXt1uIPcn8GW+y8ujNbDk9tpAliSjtbJMSMvpZVbs8MKe4xNjL3VvLWTeM9tsSQYwwYgOvojetg3U= X-Received: by 2002:a1c:8fd5:: with SMTP id r204-v6mr12860376wmd.77.1529416417190; Tue, 19 Jun 2018 06:53:37 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:adf:ed0d:0:0:0:0:0 with HTTP; Tue, 19 Jun 2018 06:53:36 -0700 (PDT) In-Reply-To: References: <20180619122359.1525D18C084@mercury.lcs.mit.edu> From: "John P. Linderman" Date: Tue, 19 Jun 2018 09:53:36 -0400 Message-ID: To: Clem Cole Content-Type: multipart/alternative; boundary="00000000000042a657056eff02db" Subject: Re: [TUHS] core X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: The Eunuchs Hysterical Society , Noel Chiappa Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" --00000000000042a657056eff02db Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable If I read the wikipedia entry for Whirlwind correctly (not a safe assumption), it was tube based, and I think there was a tradeoff of speed, as determined by power, and tube longevity. Given the purpose, early warning of air attack, speed was vital, but so, too, was keeping it alive. So a means of finding a "sweet spot" was really a matter of national security. I can understand Forrester's pride in that context. On Tue, Jun 19, 2018 at 8:58 AM, Clem Cole wrote: > > > On Tue, Jun 19, 2018 at 8:23 AM, Noel Chiappa > wrote: > >> > From: Doug McIlroy >> >> > Yet late in his life Forrester told me that the Whirlwind-connecte= d >> > invention he was most proud of was marginal testing >> >> Given the above, I'm totally gobsmacked to hear that. Margin testing was >> important, yes, but not even remotely on the same quantum level as core. > > =E2=80=8BWow -- I had exactly the same reaction. To me, core was the = second > most important invention (semiconductors switching being he first) for > making computing practical. I was thinking that systems must have been > really bad (worse than I knew) from a reliability stand point if he put > marginal testing up there as more important than core. > > Like you, I thought core memory was pretty darned important. I never use= d > a system that had Williams tubes, although we had one in storage so I kne= w > what it looked like and knew how much more 'dense' core was compared to > it. Which is pretty amazing still compare today. For the modern user, > the IBM 360 a 1M core box (which we had 4) was made up of 4 19" relay > racks, each was about 54" high and 24" deep. If you go to > CMU Computer Photos from Chris Hausler > > =E2=80=8B and scroll down you can see some pictures of the old 360 (inclu= ding a > copy of me in them circa 75/76 in front of it) to gage the size). > > > > FWIW: > I broke in with MECL which Motorola invented / developed for IBM for > System 360 and it (and TTL) were the first logic families I learned with > which to design. I remember the margin pots on the front of the 360 tha= t > we used when we were trying to find weak gates, which happened about ones > every 10 days. > > The interesting part to me is that I'm suspect the PDP-10's and the Univa= c > 1108 broke as often as the 360 did, but I have fewer memories of chasing > problems with them. Probably because it was a less of an issue that was > causing so many people to be disrupted by the 'down' time. > =E1=90=A7 > --00000000000042a657056eff02db Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
If = I read the wikipedia entry for Whirlwind correctly (not a safe assumption),= it was tube based, and I think there was a tradeoff of speed, as determine= d by power, and tube longevity. Given the purpose, early warning of air att= ack, speed was vital, but so, too, was keeping it alive. So a means of find= ing a "sweet spot" was really a matter of national security. I ca= n understand Forrester's pride in that context.

On Tue, Jun 19, 2018 at 8:5= 8 AM, Clem Cole <clemc@ccc.com> wrote:


On Tue, Jun 19, 2018 at 8:23 = AM, Noel Chiappa <jnc@mercury.lcs.mit.edu> wrote:
<= /font>
=C2=A0 =C2=A0 > From: Doug McIlroy &= lt;doug@cs.dartm= outh.edu>

=C2=A0 =C2=A0 > Yet late in his life Forrester told me that the Whirlwin= d-connected
=C2=A0 =C2=A0 > invention he was most proud of was marginal testing
<= /font>
Given the above, I'm totally gobsmacked = to hear that. Margin testing was
important, yes, but not even remotely on the same quantum level as core.
=E2=80=8BWow -- I had exactly the same reaction.=C2=A0 =C2=A0 =C2=A0To me, core= was the second most important invention (semiconductors switching being he= first) for making computing practical.=C2=A0 =C2=A0I was thinking that sys= tems must have been really bad (worse than I knew) from a reliability stand= point if he put marginal testing up there as more important than core.=C2= =A0=C2=A0
=
Like = you, I thought core memory was pretty darned important.=C2=A0 I never used = a system that had Williams tubes, although we had one in storage so I knew = what it looked like and knew how much more 'dense' core was compare= d to it.=C2=A0 =C2=A0Which is pretty amazing still compare today.=C2=A0 For= the modern user, the IBM 360 a 1M core box (which we had 4) was made up of= =C2=A0 4 19" relay racks, each was about 54" high and 24" de= ep.=C2=A0 =C2=A0 If you go to
CMU Computer Phot= os from Chris Hausler
=E2=80=8B and scroll down you c= an see some pictures of the old 360 (including a copy of me in them circa 7= 5/76 in front of it) to gage the size).



=
FWIW:=C2=A0=C2=A0
I broke in with MECL which M= otorola invented / developed for IBM for System 360 and it (and TTL) were t= he first logic families I learned with which to design.=C2=A0 =C2=A0I remem= ber the margin pots on the front of the 360 that we used when we were tryin= g to find weak gates, which happened about ones every 10 days.
=

=
The interesting part to me i= s that I'm suspect the PDP-10's and the Univac 1108 broke as often = as the 360 did, but I have fewer memories of chasing problems with them.=C2= =A0 =C2=A0Probably because it was a less of an issue that was causing so ma= ny people to be disrupted=C2=A0by the 'down' time.=C2=A0
3D""=E1=90=A7

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