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=-1.1 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 14355 invoked from network); 29 Jun 2020 09:13:03 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 29 Jun 2020 09:13:03 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id D23E99C654; Mon, 29 Jun 2020 19:13:01 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 792639C190; Mon, 29 Jun 2020 19:11:26 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=pass (1024-bit key; unprotected) header.d=planet.nl header.i=@planet.nl header.b="SkBoZvTo"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 4082E9C190; Mon, 29 Jun 2020 19:11:23 +1000 (AEST) Received: from cpsmtpb-ews06.kpnxchange.com (cpsmtpb-ews06.kpnxchange.com [213.75.39.9]) by minnie.tuhs.org (Postfix) with ESMTP id 5FA0B945A4 for ; Mon, 29 Jun 2020 19:11:20 +1000 (AEST) Received: from cpsps-ews24.kpnxchange.com ([10.94.84.190]) by cpsmtpb-ews06.kpnxchange.com with Microsoft SMTPSVC(8.5.9600.16384); Mon, 29 Jun 2020 11:11:18 +0200 X-Brand: 7abm2Q== X-KPN-SpamVerdict: e1=0;e2=0;e3=0;e4=(e1=10;e3=10;e2=11;e4=10);EVW:Whi te;BM:NotScanned;FinalVerdict:Clean X-CMAE-Analysis: v=2.3 cv=HrPt53bS c=1 sm=1 tr=0 cx=a_idp_e a=dZ5u/0G9QtS9WKCcNUBnHQ==:117 a=soxbC+bCkqwFbqeW/W/r+Q==:17 a=x1i13A_MHe4A:10 a=IkcTkHD0fZMA:10 a=nTHF0DUjJn0A:10 a=RcNwXUSJAAAA:8 a=VAHArR8Pnc1REz70x5MA:9 a=QEXdDO2ut3YA:10 a=PStBptRfm5hTyWmDLbsY:22 X-CM-AcctID: kpn@feedback.cloudmark.com Received: from smtp.kpnmail.nl ([195.121.84.13]) by cpsps-ews24.kpnxchange.com over TLS secured channel with Microsoft SMTPSVC(8.5.9600.16384); Mon, 29 Jun 2020 11:11:18 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=planet.nl; s=planet01; h=to:date:message-id:subject:mime-version:content-type:from; bh=BPcBHv6M8S+j4942berghabj01HwAwQQCs456EZW4gI=; b=SkBoZvToP631FELN5Vw6hLcDrh1AIZuewSSsEkK9lwC4qrpRryfEHEEe0GJdx8bIQ4Ra5Y44Lsl2q nAFM9K9yaHqzA6MaKZvW+FISQnmjypxyHpDMGdQVPhmZxPw2emGRAo0mPOVWHcXQOcm/i/L5klcziN Dwtgt8OsvJvrP/I0= X-KPN-VerifiedSender: Yes X-CMASSUN: 33|zfftB6FRWC4y/z/PYK4mM5HP64qa8oyWvzu63SCfqGrskL2dxzjI5hJ3g3P8HWQ LVfBX5rNaJFTrAqS73ieWqw== X-Originating-IP: 80.101.112.122 Received: from mba2.fritz.box (sqlite.xs4all.nl [80.101.112.122]) by smtp.kpnmail.nl (Halon) with ESMTPSA id 7d9bec00-b9e8-11ea-a078-005056998788; Mon, 29 Jun 2020 11:11:18 +0200 (CEST) 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: <888A9360-A6E0-4EE0-84A5-8ADD478807E1@planet.nl> Date: Mon, 29 Jun 2020 11:11:17 +0200 To: TUHS main list X-Mailer: Apple Mail (2.3445.104.11) X-OriginalArrivalTime: 29 Jun 2020 09:11:18.0279 (UTC) FILETIME=[3F90D170:01D64DF5] X-RcptDomain: minnie.tuhs.org Subject: Re: [TUHS] VFS prior to 1984 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" Date: Wed, 24 Jun 2020 14:31:34 -0400 (EDT) From: norman@oclsc.org (Norman Wilson) > Reaching outside of UNIX, RSX/11 used external supervisor-mode = processes called ACPs (ancillary control processes) to implement file = systems. I don't know exactly how they were plugged in, but I do know = they were pluggable, so their interface must have constituted a = file-system switch of some sort. RSX dates back into the 1970s. At some = point in the latter part of the 1980s, Ralph Stamerjohn (a name = instantly recognizable in the 16-bit DEC software world) gave a DECUS = talk about implementing a remote file system through ACPs: a stub ACP on = the client exporting RPCs over the network, a real one at the server = end. I remember chatting with him about how that did and didn't resemble = the way pjw had done it; interesting architectural comparison. > Norman Wilson Toronto ON I am still digesting all the inputs (thanks, all!) The above post made me realise that the delineation of what is a FSS/VFS = or not, is not so easy. I did a little bit of reading, and the concept of an ACP arrived with = RSX11D in May 1973, but only matured in RSX11M in November 1974. As I = understand it, originally in RSX11 file system code was closely tied to = the low-level device driver for each device. ACP=E2=80=99s separated the = file system code from the device driver itself, and became separate = processes. In essence there were two switches: one switch into abstract devices, = implemented in ACP code and one kernel switch to deal with hardware = interfacing. The first is indeed like a file system switch (although = still tied to specific devices). Looking at this stuff made me realise that my retro machine of choice = (the TI990) went through a similar evolution. In the early seventies it = had a sort of abstract device switch that linked to individual =E2=80=98de= vice service routines=E2=80=99 (drivers). Initially, these modelled = batch oriented =E2=80=98logical units=E2=80=99 that tied to files at the = job control level. Later (late 70=E2=80=99s), the =E2=80=98open=E2=80=99 = command would carry a file name and the file system was delegated to the = device service routine. Still later (say 1983) this was used for = networked disks. As several people have observed in this topic, indeed there appears to = be a close relationship between a device switch and a file system = switch.