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 61caa7ac for ; Wed, 22 Jan 2020 10:56:52 +0000 (UTC) Received: by minnie.tuhs.org (Postfix, from userid 112) id AB1849C20F; Wed, 22 Jan 2020 20:56:50 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 852A49C14A; Wed, 22 Jan 2020 20:56:18 +1000 (AEST) Received: by minnie.tuhs.org (Postfix, from userid 112) id E45629C102; Wed, 22 Jan 2020 20:56:15 +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 D08379C14A for ; Wed, 22 Jan 2020 20:56:12 +1000 (AEST) Received: from mba2.fritz.box ([80.101.112.122]) by smtp-cloud7.xs4all.net with ESMTPA id uDg9iiRcnrNgyuDgAiqWqT; Wed, 22 Jan 2020 11:56:10 +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: <3E0694EF-1742-4313-BA34-D4D386FF6942@planet.nl> Date: Wed, 22 Jan 2020 11:56:08 +0100 To: TUHS main list X-Mailer: Apple Mail (2.3445.104.11) X-CMAE-Envelope: MS4wfIeMfk3vcx1mQj6eD6O3sKbF/5SVfnai/nHjgIqXkAiGqj/VkhrProWI9wHimHyIwa+v4hRjYBknYmFCJ1do3E2h7EkmIILcTamqgZCy2tCwC8eX8FU2 UyCn3wPtZpZ2z2nsnJaaD7Fh0vyuGt9VFOj02cwGUITQ+nxM5WkUG6Xs Subject: Re: [TUHS] Unix on Zilog Z8000? 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" A somewhat comparable machine to the Onyx was the Zilog S8000. It ran = =E2=80=9CZeus=E2=80=9D, which was also a Unix version: https://www.mirrorservice.org/sites/www.bitsavers.org/pdf/zilog/s8000/ Instead of the MMU described below it used the Zilog segmented MMU = chips, 3 of them. These could be used to give a plain 16 bit address = space divided in 3 segments, or could be used with the segmented = addresses of the Z8001. The approach used by Onyx seems much cleaner to = me, and reminiscent of the MMU on a DG Eclipse. I think the original chips were the Z8000 (unsegmented) and the the = Z8001 (segmented). These could not abort/restart instructions and were = replaced by the Z8002 (unsegmented) and Z8003 (segmented). On these = chips one could effectively assert reset during a fault and this would = leave the registers in a state where a software routine could roll back = the faulted instruction. If the sources to the Onyx Unix survived, it would be interesting to see = if it used this capability of the Z8002 and implemented a form demand = paging. Last but not least, the Xenix overview I linked earlier = (http://seefigure1.com/images/xenix/xenix-timeline.jpg) shows Xenix = ports to 4 other Z800 machines: Paradyne, Compucorp, Bleasedale and = Kontron; maybe all of these never got to production. > Message: 7 > Date: Tue, 21 Jan 2020 21:32:51 +0000 > From: Derek Fawcus > To: The Unix Heritage Society mailing list > Subject: [TUHS] Onyx (was Re: Unix on Zilog Z8000?) > Message-ID: <20200121213251.GA25322@clarinet.employees.org> > Content-Type: text/plain; charset=3Dus-ascii >=20 > On Tue, Jan 21, 2020 at 01:28:14PM -0500, Clem Cole wrote: >> The Onyx box redated all the 68K and later Intel or other systems. >=20 > That was a fun bit of grubbing around courtesy of a bitsavers mirror > (https://www.mirrorservice.org/sites/www.bitsavers.org/pdf/onyx/). >=20 > It seems they started with a board based upon the non-segmented Z8002 > and only later switched to using the segmented Z8001. In the initial > board, they created their own MMU: >=20 > Page 6 of: = https://www.mirrorservice.org/sites/www.bitsavers.org/pdf/onyx/c8002/Onyx_= C8002_Brochure.pdf >=20 > Memory Management Controller: >=20 > The Memory Management Controller (MMC) enables the C8002 to perform > address translation, memory block protection, and separation of > instruction and data spaces. Sixteen independent map sets are > implemented, with each map set consisting of an instruction map and > a data map. Within each map there are 32 page registers. Each page > register relocates and validates a 2K byte page. The MMC generates > a 20 bit address allowing the C8002 to access up to one Mbyte of > physical memory. >=20 > So I'd guess the MMC was actually programed through I/O instuctions > to io space, and hence preserved the necessary protection domains. >=20 > Cute. I've had a background interest in the Z8000 (triggered by = reading > a Z80000 datasheet around 87/88), and always though about using > the segmented rather than unsegmented device. >=20 > The following has a bit more info about the version of System III > ported to their boxes: >=20 > = https://www.mirrorservice.org/sites/www.bitsavers.org/pdf/onyx/c8002/UNIX_= 3.0.3_Software_Release_Notice_May83.pdf >=20 > DF