From owner-freebsd-hackers Sat Oct 25 14:11:02 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id OAA23968 for hackers-outgoing; Sat, 25 Oct 1997 14:11:02 -0700 (PDT) (envelope-from owner-freebsd-hackers) Received: from dfw-ix12.ix.netcom.com (dfw-ix12.ix.netcom.com [206.214.98.12]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id OAA23960 for ; Sat, 25 Oct 1997 14:11:00 -0700 (PDT) (envelope-from wghhicks@ix.netcom.com) Received: (from smap@localhost) by dfw-ix12.ix.netcom.com (8.8.4/8.8.4) id QAA22095 for ; Sat, 25 Oct 1997 16:10:27 -0500 (CDT) Received: from atl-ga17-14.ix.netcom.com(204.32.174.174) by dfw-ix12.ix.netcom.com via smap (V1.3) id rma022079; Sat Oct 25 16:09:57 1997 Message-ID: <34525F3B.1137B612@ix.netcom.com> Date: Sat, 25 Oct 1997 17:06:03 -0400 From: Jerry Hicks Reply-To: wghhicks@ix.netcom.com Organization: TerraEarth X-Mailer: Mozilla 4.03b8 [en] (X11; I; FreeBSD 2.2-STABLE i386) MIME-Version: 1.0 To: freebsd-hackers@FreeBSD.ORG Subject: Re: Parity Ram References: <34524948.41C67EA6@est.is> Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Sender: owner-freebsd-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk Žoršur Ivarsson wrote: > > This has helped me several times when I was suspecting broken memory in > the old days (90-93) :-) > > Thordur Ivarsson ECC Memory was marginally useful for this years ago when were using NMOS RAM. Lately, most memory failures I've seen are catastrophic, taking out a whole device or better. I'm not a hardware specialist; Does 'Parity RAM' employ a conventional parity scheme, a la asynch serial communications? Didn't Richard Hamming show these to -cause- more problems than they solve? It seems I recall a number like 256K (bits/bytes/words?) as being the threshold in a proof he presented. Jerry Hicks jerry_hicks@bigfoot.com