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=-1.0 required=5.0 tests=MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 10063 invoked from network); 7 May 2022 19:06:53 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 7 May 2022 19:06:53 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 0B9CE9CEFE; Sun, 8 May 2022 05:06:52 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id E98C49CEEF; Sun, 8 May 2022 05:05:11 +1000 (AEST) Received: by minnie.tuhs.org (Postfix, from userid 112) id 39C1C9CEEF; Sun, 8 May 2022 05:03:47 +1000 (AEST) Received: from freefriends.org (freefriends.org [96.88.95.60]) by minnie.tuhs.org (Postfix) with ESMTPS id 3ECB49CEEE for ; Sun, 8 May 2022 05:03:46 +1000 (AEST) X-Envelope-From: arnold@skeeve.com Received: from freefriends.org (freefriends.org [96.88.95.60]) by freefriends.org (8.14.7/8.14.7) with ESMTP id 247J3h4Z002053 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sat, 7 May 2022 13:03:44 -0600 Received: (from arnold@localhost) by freefriends.org (8.14.7/8.14.7/Submit) id 247J3gQD002051; Sat, 7 May 2022 13:03:42 -0600 From: arnold@skeeve.com Message-Id: <202205071903.247J3gQD002051@freefriends.org> X-Authentication-Warning: frenzy.freefriends.org: arnold set sender to arnold@skeeve.com using -f Date: Sat, 07 May 2022 13:03:42 -0600 To: tuhs@minnie.tuhs.org, jnc@mercury.lcs.mit.edu References: <20220506153317.D499D18C07A@mercury.lcs.mit.edu> In-Reply-To: <20220506153317.D499D18C07A@mercury.lcs.mit.edu> 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] Alternative Implementation Proposal for Unix/370 (BTL, 1979) 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: jnc@mercury.lcs.mit.edu Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" Thanks Noel. Those reasons are quite compelling. One gets the sense that they wanted to get UNIX going on the 370 as quickly as posible. jnc@mercury.lcs.mit.edu (Noel Chiappa) wrote: > > From: Tom Lyon > > > there were a few icustomer nstallations. Bell Labs Indian Hill was one > > - so that's why TSS was the base of their UNIX port. > > "A UNIX System Implementation for System/370" (by W. A. Felton, G. L. Miller, > and J. M. Milner): > > https://www.bell-labs.com/usr/dmr/www/otherports/ibm.html > > says "code to support System/370 I/O, paging, error recording and recovery, > and multiprocessing already existed in several available operating systems, > we investigated the possibility of using an existing operating system, or at > least the machine-interface parts of one, as a base to provide these > functions for the System/370 implementation ... Of the available systems, > TSS/370 came the closest to meeting our needs and was thus chosen as the base > for our UNIX system implementation". Alas, it doesn't say which other systems > were also considered. > > > >> On May 6, 2022, at 09:39, arnold@skeeve.com wrote: > > >> So, why, given the letter from these folks, including DMR, did they go > >> ahead and use the TSS solution anyway? > > That paper says: "We initially thought about porting the UNIX operating > system directly to System/370 with minimal changes. Unfortunately, there are > a number of System/370 characteristics that, in the light of our objectives > and resources, made such a direct port unattractive. The Input/Output (I/O) > architecture of System/370 is rather complex; in a large configuration, the > operating system must deal with a bewildering number of channels, > controllers, and devices, many of which may be interconnected through > multiple paths. Recovery from hardware errors is both complex and > model-dependent. For hardware diagnosis and tracking, customer engineers > expect the operating system to provide error logs in a specific format; > software to support this logging and reporting would have to be written. ... > Finally, several models of System/370 machines provide multiprocessing, with > two (or more) processors operating with shared memory; the UNIX system did > not support multiprocessing." > > Presumably these factors outweighed the factors listed in the > Haley/London/Maranzaro/Ritchie letter. > > Noel