From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.2 Received: (qmail 29115 invoked from network); 4 Apr 2020 03:14:56 -0000 Received-SPF: pass (minnie.tuhs.org: domain of minnie.tuhs.org designates 45.79.103.53 as permitted sender) receiver=inbox.vuxu.org; client-ip=45.79.103.53 envelope-from= Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with UTF8ESMTPZ; 4 Apr 2020 03:14:56 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 361969C646; Sat, 4 Apr 2020 13:14:52 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 0F06A9C61B; Sat, 4 Apr 2020 13:14:22 +1000 (AEST) Received: by minnie.tuhs.org (Postfix, from userid 112) id BAB8F9C203; Sat, 4 Apr 2020 13:14:19 +1000 (AEST) Received: from mail.cs.dartmouth.edu (mail.cs.dartmouth.edu [129.170.212.100]) by minnie.tuhs.org (Postfix) with ESMTPS id 1066F9C14A for ; Sat, 4 Apr 2020 13:14:18 +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 0343EGTV1238534 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO) for ; Fri, 3 Apr 2020 23:14:16 -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 0343EGbV068470 for ; Fri, 3 Apr 2020 23:14:16 -0400 Received: (from doug@localhost) by tahoe.cs.Dartmouth.EDU (8.15.2/8.15.2/Submit) id 0343EGgH068467 for tuhs@tuhs.org; Fri, 3 Apr 2020 23:14:16 -0400 From: Doug McIlroy Message-Id: <202004040314.0343EGgH068467@tahoe.cs.Dartmouth.EDU> Date: Fri, 03 Apr 2020 23:14:16 -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] Research PBX legacy 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: , Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" Prologue to TPC. Bob Morris did a visiting-researcher stint at AT&T, where he became aware of infelicitous software architure proposed for ESS 5. He thought Research could do it better. Ken, Joe, and Lee bit. Lee's architecture was indeed novel: every device in the system, right down to each touch-tone button, was modeled as a process. Only after the clean model was working were some processes--notably the buttons--jammed together to cinch in the process table. The team got the switch working in a matter of months--in time to demonstrate it to Indian Hill before ESS was irrevocably set in stone. ESS architecture was indeed rethought, taking some ideas from TPC. TPC was named after "TPC, The Phone Company" in the 1967 film, "The President's Analyst". Doug