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=-0.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE 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 363ff8b2 for ; Sat, 16 Jun 2018 13:16:39 +0000 (UTC) Received: by minnie.tuhs.org (Postfix, from userid 112) id 5A34AA1829; Sat, 16 Jun 2018 23:16:38 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 1B87F9EDE8; Sat, 16 Jun 2018 23:16:29 +1000 (AEST) Received: by minnie.tuhs.org (Postfix, from userid 112) id 24EC29EDE8; Sat, 16 Jun 2018 23:16:28 +1000 (AEST) X-Greylist: delayed 1083 seconds by postgrey-1.35 at minnie.tuhs.org; Sat, 16 Jun 2018 23:16:27 AEST Received: from mail.cs.Dartmouth.EDU (mail.cs.dartmouth.edu [129.170.212.100]) by minnie.tuhs.org (Postfix) with ESMTPS id 9F1BD9B5D7 for ; Sat, 16 Jun 2018 23:16:27 +1000 (AEST) Received: from tahoe.cs.Dartmouth.EDU (tahoe.cs.dartmouth.edu [129.170.212.20]) by mail.cs.Dartmouth.EDU (8.15.2/8.15.2) with ESMTPS id w5GCwNVY012096 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Sat, 16 Jun 2018 08:58:23 -0400 Received: from tahoe.cs.Dartmouth.EDU (localhost.localdomain [127.0.0.1]) by tahoe.cs.Dartmouth.EDU (8.15.2/8.14.3) with ESMTP id w5GCwN2G014687 for ; Sat, 16 Jun 2018 08:58:23 -0400 Received: (from doug@localhost) by tahoe.cs.Dartmouth.EDU (8.15.2/8.15.2/Submit) id w5GCwNDN014646 for tuhs@tuhs.org; Sat, 16 Jun 2018 08:58:23 -0400 From: Doug McIlroy Message-Id: <201806161258.w5GCwNDN014646@tahoe.cs.Dartmouth.EDU> Date: Sat, 16 Jun 2018 08:58:23 -0400 To: tuhs@tuhs.org User-Agent: Heirloom mailx 12.5 7/5/10 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit 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: , Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" > jay forrester first described an invention called core memory in a lab notebook 69 years ago today. Core memory wiped out competing technologies (Williams tube, mercury delay line, etc) almost instantly and ruled for over twent years. Yet late in his life Forrester told me that the Whirlwind-connected invention he was most proud of was marginal testing: running the voltage up and down once a day to cause shaky vacuum tubes to fail during scheduled maintenance rather than randomly during operation. And indeed Wirlwind racked up a notable record of reliability. Doug