From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,da46977c58c329df X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2002-02-08 13:32:45 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!dispose.news.demon.net!demon!peernews!peer.cwci.net!news5-gui.server.ntli.net!ntli.net!news11-gui.server.ntli.net.POSTED!not-for-mail Sender: mjw@golux Newsgroups: comp.lang.ada Subject: Re: Ada's Slide To Oblivion ... References: <4519e058.0201310714.650888e1@posting.google.com> <3C598CAA.7040801@home.com> <3C59FCD3.928144FB@adaworks.com> <7v8za79id0.fsf@vlinux.voxelvision.no> <3C6288CB.3227AF20@cfmu.eurocontrol.be> <3C62D397.8040001@mail.com> <%rC88.3860$oC3.2148048@typhoon.san.rr.com> <3C63AB8A.F52337D8@cfmu.eurocontrol.be> <7vlme4w4ax.fsf@vlinux.voxelvision.no> <3c63c7a5.398689067@news.cis.dfn.de> From: Matthew Woodcraft Message-ID: <87pu3fhddu.fsf@golux.ecstacy.dynamic.greenend.org.uk> User-Agent: Gnus/5.0808 (Gnus v5.8.8) Emacs/21.1 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: 08 Feb 2002 21:28:29 +0000 NNTP-Posting-Host: 213.107.104.73 X-Complaints-To: abuse@ntlworld.com X-Trace: news11-gui.server.ntli.net 1013203714 213.107.104.73 (Fri, 08 Feb 2002 21:28:34 GMT) NNTP-Posting-Date: Fri, 08 Feb 2002 21:28:34 GMT Organization: ntl Cablemodem News Service Xref: archiver1.google.com comp.lang.ada:19797 Date: 2002-02-08T21:28:29+00:00 List-Id: nickroberts@ukf.net (Nick Roberts) writes: > On Fri, 08 Feb 2002 12:23:48 GMT, Ole-Hjalmar Kristensen > wrote: > >> David Brown wrote: > >> On, say, a high end PDP-11, or a 68000, or an 8086 (but not its > >> progeny!), code space and data space are physically separate. There > >> are wires that come out of the processor to say which space to use. On > >> such a system there's NO WAY to write to code space, and it's not > >> impossible that > It is not fantasy, but I think factually slightly imperfect. > > As far as I recall, neither the 8086 nor the 8088 (nor any of their > progeny) ever had this kind of control signal. A genuine 8086 had two pins which indicated the segment register which had been used to calculate an address. I imagine an 8088 did too. I suppose this could reasonably be used to separate code space from data space if all the code were in ROM. I also once saw a suggestion that it could be used to have a separate stack space. -M-