From owner-freebsd-hardware Tue Dec 11 10:32:23 2001 Delivered-To: freebsd-hardware@freebsd.org Received: from mail11.speakeasy.net (mail11.speakeasy.net [216.254.0.211]) by hub.freebsd.org (Postfix) with ESMTP id 4CE6D37B423 for ; Tue, 11 Dec 2001 10:32:05 -0800 (PST) Received: (qmail 22195 invoked from network); 11 Dec 2001 18:32:04 -0000 Received: from unknown (HELO laptop.baldwin.cx) ([64.81.54.73]) (envelope-sender ) by mail11.speakeasy.net (qmail-ldap-1.03) with SMTP for ; 11 Dec 2001 18:32:04 -0000 Message-ID: X-Mailer: XFMail 1.4.0 on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: <15382.20261.860671.461839@caddis.yogotech.com> Date: Tue, 11 Dec 2001 10:31:59 -0800 (PST) From: John Baldwin To: Nate Williams Subject: Re: i286 Cc: freebsd-hardware@FreeBSD.ORG, Cc: freebsd-hardware@FreeBSD.ORG, 9ustavo 9onzalez 9iron , Bakul Shah Sender: owner-freebsd-hardware@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On 11-Dec-01 Nate Williams wrote: >> > > Exist some kind of FreeBSD's version for intel 286 processor? >> > >> > Never in a million years. There exists no 'real' unix for the 286, >> > since the 286 hardware is incapable of protecting processes well enough >> > to be safe. >> >> Not that anyone cares any more but... i286 provides good >> enough protection -- you can have each prcoess in its own >> protected address space without any external h/w support >> (like we had to do for Moto 68000 based machines). What it >> didn't provide was support for paging. > > As I understand, don't you need paging for 'real' protection to work > right, otherwise you're limited to one/two processes on the box? Well, you have to do swapping to handle virtual memory rather than virtual memory, so it does limit your concurrency. You might be able to play tricks to emulate pages by using multiple selectors but that would be ugly. It would be a bit slow anyways. Go find a 486. :) -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message