From owner-freebsd-hardware Mon Sep 16 20:56:28 1996 Return-Path: owner-hardware Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id UAA05307 for hardware-outgoing; Mon, 16 Sep 1996 20:56:28 -0700 (PDT) Received: from mx.serv.net (mx.serv.net [199.201.191.10]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id UAA05294; Mon, 16 Sep 1996 20:56:15 -0700 (PDT) Received: from MindBender.serv.net by mx.serv.net (8.7.5/SERV Revision: 2.30) id UAA07939; Mon, 16 Sep 1996 20:50:45 -0700 (PDT) Received: from localhost.HeadCandy.com (michaelv@localhost.HeadCandy.com [127.0.0.1]) by MindBender.serv.net (8.7.5/8.7.3) with SMTP id UAA19977; Mon, 16 Sep 1996 20:36:33 -0700 (PDT) Message-Id: <199609170336.UAA19977@MindBender.serv.net> X-Authentication-Warning: MindBender.serv.net: Host michaelv@localhost.HeadCandy.com [127.0.0.1] didn't use HELO protocol To: Jeffrey Hsu cc: hardware@freefall.freebsd.org Subject: Re: passive backplane (was Re: Any Pentium boards with more than 4 PC) slots? In-reply-to: Your message of Mon, 16 Sep 96 09:36:55 -0700. <199609161636.JAA15362@freefall.freebsd.org> Date: Mon, 16 Sep 1996 20:36:33 -0700 From: "Michael L. VanLoon -- HeadCandy.com" Sender: owner-hardware@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk >Speaking of passive backplanes, I have a question. What are they >used for? The hardware engineer I asked a while ago didn't give >a satisfying answer. In fact, I've forgotten what it was. But it >must be good for something, because I keep seeing passive backplanes >advertised in embedded systems magazines. Two things, primarily: 1) Creating a computer where you can just "swap-out" the CPU, and "swap-in" a better one. I. e. put the entire motherboard electronics on a PCI-ish board, and plug it into a back-plane. Then, when you want something better, yank the card and plug in a new one. In reality, this has never been cheaper than buying a new motherboard. Usually the companies that make something this cool end up charging twice as much for the technology. 2) Extending your bus so you can have fifteen or twenty cards plugged in. ----------------------------------------------------------------------------- Michael L. VanLoon michaelv@MindBender.serv.net --< 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... -----------------------------------------------------------------------------