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=0.2 required=5.0 tests=MAILING_LIST_MULTI, MISSING_HEADERS,RCVD_IN_DNSWL_NONE autolearn=no autolearn_force=no version=3.4.4 Received: (qmail 25871 invoked from network); 15 Aug 2020 16:57:02 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 15 Aug 2020 16:57:02 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 0D58D9DF9F; Sun, 16 Aug 2020 02:56:59 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 9C4AC9B5EC; Sun, 16 Aug 2020 02:56:26 +1000 (AEST) Received: by minnie.tuhs.org (Postfix, from userid 112) id 9386A9B5EC; Sun, 16 Aug 2020 02:56:22 +1000 (AEST) Received: from mail.cheswick.com (unknown [96.93.158.218]) by minnie.tuhs.org (Postfix) with ESMTPS id C2D679B5D7 for ; Sun, 16 Aug 2020 02:56:19 +1000 (AEST) Received: from [IPv6:2607:fb90:3b1d:d033:7ce3:9772:d818:535a] (unknown [172.56.22.174]) by mail.cheswick.com (Postfix) with ESMTPA id 2B7EB2383A2; Sat, 15 Aug 2020 12:55:35 -0400 (EDT) Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable From: William Cheswick Mime-Version: 1.0 (1.0) Date: Sat, 15 Aug 2020 12:55:17 -0400 Message-Id: <4C96E13E-353F-4828-B408-758EAF2E270B@cheswick.com> References: <176D143B-8C1A-4CAB-94E9-5433DBE7E4A6@humeweb.com> In-Reply-To: <176D143B-8C1A-4CAB-94E9-5433DBE7E4A6@humeweb.com> X-Mailer: iPad Mail (17G68) Subject: Re: [TUHS] A/UX [was Linux is on-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: The Eunuchs Hysterical Society Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" The wire lengths were important in CDC CPUs. I once saw an expert from CDC p= oking through the rats nest of wires on the backplane, yanking the wires aro= und with his flashlight, and pulled one out thinking it was the wrong length= . It was. Message by ches. Tappos by iPad. > On Aug 14, 2020, at 11:08 PM, Andrew Hume wrote: >=20 > =EF=BB=BFnot on the cyber 72 we shared, dave. > it was, in fact, a length of wire. > the 72 had one length, and the 76 had a shorter length. > (i guess you could call that a sort-of timing capacitor?) >=20 > i watched a cyber technician change the wires for the > purposes of doing a verification test. >=20 >> On Aug 14, 2020, at 7:02 PM, Dave Horsfall wrote: >>=20 >>> On Fri, 14 Aug 2020, Rich wrote: >>>=20 >>> On a vaguely related note, I found it amusing that there was a well know= n hack for Cray's (or perhaps 6600's) which were misbehaving: put a Tektroni= x scope probe on a test point that generally had one there during final syst= em checkout. The load (extremely mnimal by design) was just enough to stabil= ize the system. >>=20 >> There was also the story about the major difference between a Cyber 72 an= d a Cyber 73 was just a timing capacitor... Very expensive capacitor :-) >>=20 >> -- Dave