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 a321317e for ; Tue, 3 Mar 2020 14:20:04 +0000 (UTC) Received: by minnie.tuhs.org (Postfix, from userid 112) id 3207D9D653; Wed, 4 Mar 2020 00:20:00 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 059D393D90; Wed, 4 Mar 2020 00:19:30 +1000 (AEST) Received: by minnie.tuhs.org (Postfix, from userid 112) id 1729D93D90; Wed, 4 Mar 2020 00:19:27 +1000 (AEST) Received: from lb1-smtp-cloud9.xs4all.net (lb1-smtp-cloud9.xs4all.net [194.109.24.22]) by minnie.tuhs.org (Postfix) with ESMTPS id 1DDC593D35 for ; Wed, 4 Mar 2020 00:19:25 +1000 (AEST) Received: from mba2.fritz.box ([80.101.112.122]) by smtp-cloud9.xs4all.net with ESMTPA id 98OJjVDSd9Im298OKjztL4; Tue, 03 Mar 2020 15:19:24 +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: Tue, 3 Mar 2020 15:19:22 +0100 To: TUHS main list X-Mailer: Apple Mail (2.3445.104.11) X-CMAE-Envelope: MS4wfD6tmmb1tWYfzX/6USJj4qJlglzWK4KcLvGRKzdXqJiuqze5TSj17+A4kUOLuO8R+YLEF8roJPPQ1t2pSXJ/Cjn+Z7WS4suxr9oAeZgduR7V9Y6Bifwy NnmiXObbyBOqleeq1p4lIcOHWurF1EOTsja6y/WDKYbkfpYSUeSjifVa Subject: [TUHS] Early Datakit 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=E2=80=99m making a little progress with early Datakit & Unix. It would seem that there were various experimental protocols before URP = was arrived upon. The first protocol appears to have been designed by Chesson in 1979. One = Fraser paper says: ""The first Datakit protocols used a packet structure = that was aligned with cell boundaries. Chesson designed a file transfer = protocol that transported data in variable length packets, each ending = with a trailer.=E2=80=9D I think this protocol is being described in his = paper "Datakit Software Architecture=E2=80=9D (vol. 2, pp. 20.2.1-20.2.5 = Proceedings of the IEEE Int. Conf. on Communications, June 1979, Boston) = - which unfortunately does not seem to be available in the IEEE online = library. Maybe it will surface some day. Next there was a protocol tied to a Datakit terminal interface board = that used an 8-slot packet sequence/acknowledge mechanism that carried = over into URP. Not much appears to have been published about this. The most interesting experiment seems to have been a project by Luderer, = Che and Marshall to build a Datakit-based distributed Unix in 1980/81. = Marshall is credited by Fraser as one of the inventors of the URP = protocol. The papers are =E2=80=9CA virtual switch as the basis for = distributed systems=E2=80=9D and =E2=80=9CA distributed unix system = based on a virtual circuit switch=E2=80=9D (available online from the = ACM library). The first has a good overview description of how early Datakit worked = (including interface hardware) and describes the Network Kernel or =E2=80=9C= NK protocol=E2=80=9D. It would seem that URP combines the flow & = retransmission control from the terminal interface board with the = concept of a single simple receiver algorithm from NK. Unfortunately the = paper does not describe the design of the NK transmitter algorithm(s). = It confirms that everything ran on V7, but it remains unclear how the = Datakit channels were exposed to the user (I currently assume as a = cluster of character devices, with the major number identifying the = switch connection and the minor number identifying the channel - similar = to what later would be used in V8). The second has a description of a modified Unix system, where clients = (=E2=80=9CS-Unix=E2=80=9D) talk to file servers (=E2=80=9CF-Unix=E2=80=9D)= , with the file servers mounted into the local file tree of the client. = This appears to predate the work of Weinberger for the V8 network file = system and its implementation appears different. Questions: - Are Luderer, Che and Marshall still around? (especially Bill Marshall = might still recall some more details of the genesis of the URP protocol) - Any recollections about S/F-Unix and how it did or did not influence = V8-V10/Plan9?=