From owner-freebsd-questions Tue Jun 18 08:48:34 1996 Return-Path: owner-questions Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id IAA04819 for questions-outgoing; Tue, 18 Jun 1996 08:48:34 -0700 (PDT) Received: from portal.spi.net ([199.238.225.153]) by freefall.freebsd.org (8.7.5/8.7.3) with SMTP id IAA04799; Tue, 18 Jun 1996 08:48:29 -0700 (PDT) Received: from MindBender.HeadCandy.com (root@MindBender.HeadCandy.com [199.238.225.168]) by portal.spi.net (8.6.12/8.6.9) with ESMTP id IAA26626; Tue, 18 Jun 1996 08:48:24 -0700 Received: from localhost.HeadCandy.com (michaelv@localhost.HeadCandy.com [127.0.0.1]) by MindBender.HeadCandy.com (8.7.5/8.6.9) with SMTP id IAA16110; Tue, 18 Jun 1996 08:48:21 -0700 (PDT) Message-Id: <199606181548.IAA16110@MindBender.HeadCandy.com> X-Authentication-Warning: MindBender.HeadCandy.com: Host michaelv@localhost.HeadCandy.com [127.0.0.1] didn't use HELO protocol To: "Eloy A. Paris" cc: hardware@freebsd.org, questions@freebsd.org Subject: Re: FreeBSD works with Cy486DLC processors? In-reply-to: Your message of Tue, 18 Jun 96 09:13:02 -0400. <2.2.16.19960618093049.301ff69c@zeus.ven.ra.rockwell.com> Date: Tue, 18 Jun 1996 08:48:14 -0700 From: "Michael L. VanLoon -- HeadCandy.com" Sender: owner-questions@freebsd.org X-Loop: FreeBSD.org Precedence: bulk >Well, I do not have an external cache. I was talking about the internal >cache. That one is disabled. But anyway, what does the internal cache have >to do with the mother board design? That is internal to the processor... The >external cache is also disabled because I don't have one. The CPU's internal cache requires the motherboard to help it with bus snooping and invalidating addresses that another bus-master on the bus writes. I. e. without help, if a bus-master writes something to memory that is also in the cache, the CPU has no idea that data has just become stale without help from the motherboard. So now there is data in the cache that is different from that same address' data in RAM. (Yes, I know there are smarter processors, but AFAIK this is how the 486DLC does it.) ----------------------------------------------------------------------------- Michael L. VanLoon michaelv@HeadCandy.com --< Free your mind and your machine -- NetBSD free un*x >-- NetBSD working ports: 386+PC, Mac 68k, Amiga, Atari 68k, HP300, Sun3, Sun4/4c/4m, DEC MIPS, DEC Alpha, PC532, VAX, MVME68k, arm32... NetBSD ports in progress: PICA, others... Roll your own Internet access -- Seattle People's Internet cooperative. If you're in the Seattle area, ask me how. -----------------------------------------------------------------------------