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 2019b09a for ; Wed, 20 Jun 2018 20:11:53 +0000 (UTC) Received: by minnie.tuhs.org (Postfix, from userid 112) id D3EFAA17CD; Thu, 21 Jun 2018 06:11:52 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id D63499EDF1; Thu, 21 Jun 2018 06:11:30 +1000 (AEST) Received: by minnie.tuhs.org (Postfix, from userid 112) id C4E579EDF1; Thu, 21 Jun 2018 06:11:26 +1000 (AEST) Received: from mail.cs.Dartmouth.EDU (mail.cs.dartmouth.edu [129.170.212.100]) by minnie.tuhs.org (Postfix) with ESMTPS id 5DCCC9EDE7 for ; Thu, 21 Jun 2018 06:11:26 +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 w5KKBOis020367 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Wed, 20 Jun 2018 16:11:24 -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 w5KKBO50040374 for ; Wed, 20 Jun 2018 16:11:24 -0400 Received: (from doug@localhost) by tahoe.cs.Dartmouth.EDU (8.15.2/8.15.2/Submit) id w5KKBOT5040344 for tuhs@tuhs.org; Wed, 20 Jun 2018 16:11:24 -0400 From: Doug McIlroy Message-Id: <201806202011.w5KKBOT5040344@tahoe.cs.Dartmouth.EDU> Date: Wed, 20 Jun 2018 16:11:24 -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" > > Yet late in his life Forrester told me that the Whirlwind-connected > > invention he was most proud of was marginal testing > I'm totally gobsmacked to hear that. Margin testing was > important, yes, but not even remotely on the same quantum > level as core. > In trying to understand why he said that, I can only suppose that he felt that > core was 'the work of many hands'...and so he only deserved a share of the > `credit for it. It is indeed a striking comment. Forrester clearly had grave concerns about the reliability of such a huge aggregation of electronics. I think jpl gets to the core of the matter, regardless of national security: > Whirlwind ... 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. If you extrapolate the rate of replacement of vacuum tubes in a 5-tube radio to a 5000-tube computer (say nothing of the 50,000-tube machines for which Whirlwind served as a prototype), computing looks like a crap shoot. In fact, thanks to the maintenance protocol, Whirlwind computed reliably--a sine qua non for the nascent industry.