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 5cf24127 for ; Sun, 26 Jan 2020 21:26:32 +0000 (UTC) Received: by minnie.tuhs.org (Postfix, from userid 112) id 4431A9C622; Mon, 27 Jan 2020 07:26:31 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 0743C9C60F; Mon, 27 Jan 2020 07:26:12 +1000 (AEST) Received: by minnie.tuhs.org (Postfix, from userid 112) id B76969C60F; Mon, 27 Jan 2020 07:26:10 +1000 (AEST) Received: from lb1-smtp-cloud7.xs4all.net (lb1-smtp-cloud7.xs4all.net [194.109.24.24]) by minnie.tuhs.org (Postfix) with ESMTPS id 8829C9C203 for ; Mon, 27 Jan 2020 07:26:09 +1000 (AEST) Received: from mba2.fritz.box ([80.101.112.122]) by smtp-cloud7.xs4all.net with ESMTPA id vpPxi9sqerNgyvpPyiIsZ9; Sun, 26 Jan 2020 22:26:06 +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 \(3445.104.11\)) Date: Sun, 26 Jan 2020 22:26:05 +0100 References: To: TUHS main list In-Reply-To: Message-Id: X-Mailer: Apple Mail (2.3445.104.11) X-CMAE-Envelope: MS4wfAP+vXHZcnXt31Hh/LS7xtSqqxz/xjVgDmWUe+GpZn70WaNTiU2CrHE3yoY6TVYS3O4EnHDk2cRbkeXxNWtrtau+sf6KITuEL2+e+im+9TLDi1lizzy2 R5y8p1LZj5bNpnc2UzXYJ+YHxre3CW/DhxTEYpHVtlbpVbjO4VU2NmxR Subject: Re: [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" On 26 Jan 2020, at 17:56, Ken Thompson wrote: > the pierce loop had its own protocol on its own wire. > that meant it could only be local-area. the PL was > in operation on a packard-bell 516 when i arrived > at the labs in june '66. carl christensen was the > software person for both the loop and the 516. > i assume that pierce and condon were the hw > guys, but that was before my time. Ah, so the Pierce loop was operational several years before the papers = were submitted to BSTJ. That explains a lot. > spider was similar, but was designed to run on > the standard telephone T1 lines. thus, the whole > idea was more wide-area. the major draw back > of spider, and probably the reason it was never > really used, was that it couldnt make a connection. > all connections were pre-created at boot time. The Spider report has a section on the protocol for making/breaking = connections dynamically, but this is not used in the surviving programs = which hard code a destination (channel). I wondered about that when Noel = first found the sources for =E2=80=99nfs=E2=80=99. Maybe this connection = protocol was planned but never implemented. > a lesser reason was that the controller was a > tempo computer that no one loved. the system > software sucked. quickly it became unmaintained. > i think tempo went out of business. anyway, the > spider controller was the first and only tempo > computer that i saw or even heard of. The video that Sandy Fraser recorded has a segment about that at 25:30. = Apparently, just before Christmas Ed David gave him $60K budget to buy a = computer to build the Spider switch. The catch was that it had to be = delivered before New Year. With the above sentiment in mind it was = perhaps no surprise that Tempo had a unit sitting on the shelf that = could be shipped in that time frame. > On Sun, Jan 26, 2020 at 6:05 AM Paul Ruizendaal wrote: > 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 >=20 > 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 >=20 > 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. >=20 > 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. >=20 > 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. >=20 > 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. >=20 > 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. >=20 > 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. >=20 > Does anybody on the list recall whether Spider was a parallel effort = or a continuation of the earlier work? >=20