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=-1.0 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, MAILING_LIST_MULTI,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 32743 invoked from network); 1 Mar 2022 01:29:01 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 1 Mar 2022 01:29:01 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id CF3849CE7D; Tue, 1 Mar 2022 11:28:57 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 7045F9CE44; Tue, 1 Mar 2022 11:25:14 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=pass (2048-bit key; unprotected) header.d=iitbombay-org.20210112.gappssmtp.com header.i=@iitbombay-org.20210112.gappssmtp.com header.b="kN6iuqCw"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 212AF9CC02; Tue, 1 Mar 2022 11:25:13 +1000 (AEST) Received: from mail-qv1-f51.google.com (mail-qv1-f51.google.com [209.85.219.51]) by minnie.tuhs.org (Postfix) with ESMTPS id 2A2799CBCE for ; Tue, 1 Mar 2022 11:25:12 +1000 (AEST) Received: by mail-qv1-f51.google.com with SMTP id e22so15552084qvf.9 for ; Mon, 28 Feb 2022 17:25:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=iitbombay-org.20210112.gappssmtp.com; s=20210112; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=g2dbob9nr51hqFepMbJQa+lOKJB7C7C6CLwdFKNqrhY=; b=kN6iuqCwrGyIrMwDsYglaXgigZf6oID2Gjj61OO70z4RRS2vE/Bup5WbuT8kYebY+O yAngjTJsRdCscHxYOuVg5neGfBz1MaEF3MBq6XdDkWtBXK8JYOOtEjFpB2YcpeJxVHdW v7l+NX4zHkkBsJDR1PQSyByvGEfQACeK4LCdJn0pztVM/DCSbWH5beMtgKyYoKrQAH9p yGrvsgSiJLgVXnOUcynK0V8sqzooFO5UshtCuuzXPFQ2G9sY1G0cqmzzQR+TZdLbNz+M Y9s2yBmYtHrfYqa1ZccRYkCrHvt57GIrPl926VOz6szpZAigUOxx4CIJvf3RZP+SWdFl ri/Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=g2dbob9nr51hqFepMbJQa+lOKJB7C7C6CLwdFKNqrhY=; b=kUPRdSMBBXssccM8rBvOHzmUlQezxlnVO+3QbFEh1x78o/riqxvsb7ZQ/0ycJCafCI rhvv+HpVgn2eefeMqkRVFo1lxJiA7W0MUuAIZlr2Gix08FYCZI3MrEHt2S7MtuSzreQm aY+IZOzbVERXidjBSP1sGnbmjoIQbB0W9Z+3iKT/1XbyH9RzfSzsUuHwEoudwdC9HkpJ rRnRr0wLkBRuxe8efI3SpcYzMnygjfMTrOT0LKauUmi6FqoozHRW/DYNwJaHqQ8aDXWu LwJfN6h5+eB5iC/yN6Qyuhoq6kdyvM9VVWoj0OBfX84HkvGSz2DL74X7WT4kKYBrmmP6 +WFg== X-Gm-Message-State: AOAM533ktlPvwfBNtA4gg9XNd9oqIhwJ5k3A9niOSt036mooBr/focL7 8z9c/nQHMtViDaUqJSD4rBv8RQ== X-Google-Smtp-Source: ABdhPJxUKFVJ7C6h9INk79MLg1yaaS8JiYza7p+e6pOGIYAO/eo4m1MnOPv+veAsWRhy750svQZs/g== X-Received: by 2002:a0c:d7c2:0:b0:433:4b0f:bac with SMTP id g2-20020a0cd7c2000000b004334b0f0bacmr2825357qvj.13.1646097911126; Mon, 28 Feb 2022 17:25:11 -0800 (PST) Received: from smtpclient.apple (107-215-223-229.lightspeed.sntcca.sbcglobal.net. [107.215.223.229]) by smtp.gmail.com with ESMTPSA id v8-20020a05620a090800b00648b78de69fsm5799485qkv.4.2022.02.28.17.25.09 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 28 Feb 2022 17:25:10 -0800 (PST) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 15.0 \(3693.60.0.1.1\)) From: Bakul Shah In-Reply-To: <4e3c05d2-2496-b917-f1f4-1c6cba9ef58a@gmail.com> Date: Mon, 28 Feb 2022 17:25:09 -0800 Content-Transfer-Encoding: quoted-printable Message-Id: <85538B2F-7FDF-4D97-B7F0-F71977408D8F@iitbombay.org> References: <4e3c05d2-2496-b917-f1f4-1c6cba9ef58a@gmail.com> To: Will Senn X-Mailer: Apple Mail (2.3693.60.0.1.1) Subject: Re: [TUHS] Memory on Lion's v6 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: , Cc: TUHS main list Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" On Feb 27, 2022, at 9:48 PM, Will Senn wrote: >=20 > It seems like he must have had an MMU and 128k memory, This is covered in the Lions book. For instance On the PDP11/40 the memory management unit consists of two sets of registers for mapping virtual addresses to physical addresses. These are known as =E2=80=9Cactive page registers=E2=80=9D = or =E2=80=9Csegmentation registers=E2=80=9D. One set is used when the processor is in user mode and the other set, in kernel mode. Changing the contents of these registers changes the details of these mappings. The ability to make these changes is a privilege that the operating system keeps firmly to itself. Also see section 7 and in particular 7.9. And may be more!=