From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) 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=3.4.2 Received: from minnie.tuhs.org (minnie.tuhs.org [45.79.103.53]) by inbox.vuxu.org (OpenSMTPD) with ESMTP id e2c080fd for ; Sun, 26 Jan 2020 14:05:16 +0000 (UTC) Received: by minnie.tuhs.org (Postfix, from userid 112) id 4002F9C10B; Mon, 27 Jan 2020 00:05:15 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id DD1E59C105; Mon, 27 Jan 2020 00:04:42 +1000 (AEST) Received: by minnie.tuhs.org (Postfix, from userid 112) id 39DAB9C105; Mon, 27 Jan 2020 00:04:40 +1000 (AEST) Received: from lb2-smtp-cloud7.xs4all.net (lb2-smtp-cloud7.xs4all.net [194.109.24.28]) by minnie.tuhs.org (Postfix) with ESMTPS id 084249C101 for ; Mon, 27 Jan 2020 00:04:38 +1000 (AEST) Received: from mba2.fritz.box ([80.101.112.122]) by smtp-cloud7.xs4all.net with ESMTPA id viWgi837XrNgyviWhiGyrx; Sun, 26 Jan 2020 15:04:37 +0100 From: Paul Ruizendaal Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.11\)) Message-Id: Date: Sun, 26 Jan 2020 15:04:34 +0100 To: TUHS main list X-Mailer: Apple Mail (2.3445.104.11) X-CMAE-Envelope: MS4wfIKcNHGvhRao/V5UZfogUPnc3ZoZxt93R06B4/eeJb3mut3xdT10XpTvyoFP97GaBvaYfm2wzP6nAuXdnwoZ/4DtsF4tIw2WMUdrw3XTq0/Y4qWVYcSS i8Sl32qOpSVlscQ30GGOB2rLrl8ibdDR1ic3ynrCAxElxNDwL5Fj3gbB Subject: [TUHS] More Spider 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" I noted with much pleasure that the main bitsavers site is back up, and = that at some point it has added a full set of scans of =E2=80=9CDatamation= =E2=80=9D. The Feb 1975 issue contains an article from Dr. Fraser about = Spider and the network setup in Murray Hill early in 1975: http://bitsavers.org/pdf/datamation/197502.pdf For ease of reference I have also temporarily put the relevant 4 pages = of the issue here: https://gitlab.com/pnru/spider/blob/master/spider.pdf I find the graphic that shows how Spider connected machines and = departments the most interesting, as it helps understand how the pro=E2=80= =99s and con=E2=80=99s of Arpa Unix might have been perceived at that = time. The more I read, the more confused I become whether the =E2=80=9CPierce = loop=E2=80=9D was a precursor to =E2=80=9CSpider=E2=80=9D or a parallel = effort. The facts appear to be that John Pierce = (https://en.wikipedia.org/wiki/John_R._Pierce) submitted his paper to = BSTJ in December 1970, essentially describing a loop network with fixed = size short datagrams, suggesting T1 frames. It is quite generic. In = February 1971 W.J. Kropfl submits a paper that describes an = implementation of the ideas in the Pierce paper with actual line = protocols and a TIU. In October 1971 C.H. Coker describes in a 3rd paper = how to interact with this TIU from a H516 programming perspective. Several Spider papers mention that the project was started in 1969 and = that the first Spider link was operational in 1972. The team appears to = be entirely different: the h/w is credited to Condon and Weller, and the = s/w to Frazer, Jensen and Plaugher. The Spider TIU is much more complex = (200 TTL chips vs. 50 in the Kropfl TIU). The main reason for that - at = first glance - appears to be that in the Spider network the TIU handled = guaranteed in order delivery (i.e managed time outs and = retransmissions), whereas in the Kropfl implementation this was left to = the hosts. It would seem logical that the latter was an evolution of the former, = having been developed at the same site at the same time. A 1981 book = seems to take that view as well: =E2=80=9CLocal Computer Network = Technologies=E2=80=9D by Carl Tropper includes the text "Spider Spider = is an experimental data communications network which was built at the = Bell Telephone Laboratories (Murray Hill, New Jersey) under the = direction of A. G. Fraser. A detailed description of the network is = given by Fraser [FRAS74]. This network was built with the notion of = investigating Pierce's idea of ...=E2=80=9D The chapter is titled =E2=80=9C= The Pierce loop and its derivatives=E2=80=9D. This is a much as Google = will give me - if somebody has the book please let me know. On the other hand, the Spider papers do not mention the Kropfl network = or Pierce=E2=80=99s paper at all. The graphic in Datamation appears to = show two Kropfl loops as part of the network setup. Yet, this is = described in the accompanying text as "4. Honeywell 5l6: Supports = research into comunications techniques and systems. The machine has a = serial loop I/O bus threaded through several labs at Murray Hill. = Equipment under test is connected either directly to the bus or to a = minicomputer which is then connected to the bus. Also avail- able are = graphics display terminals and a device that can write read-only memory = chips.=E2=80=9D Maybe this is a different bus, but if it is the same as = the Kropfl loop, to call it a =E2=80=9Cserial loop I/O bus=E2=80=9D = suggests it was a parallel effort unrelated to Spider. Does anybody on the list recall whether Spider was a parallel effort or = a continuation of the earlier work?