From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.7 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,HTML_MESSAGE,MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham autolearn_force=no version=3.4.2 Received: from minnie.tuhs.org (minnie.tuhs.org [45.79.103.53]) by inbox.vuxu.org (OpenSMTPD) with ESMTP id befbeb80 for ; Mon, 25 Nov 2019 18:30:12 +0000 (UTC) Received: by minnie.tuhs.org (Postfix, from userid 112) id 01F519C620; Tue, 26 Nov 2019 04:30:10 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 2BA6693D74; Tue, 26 Nov 2019 04:29:50 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=pass (2048-bit key; unprotected) header.d=bsdimp-com.20150623.gappssmtp.com header.i=@bsdimp-com.20150623.gappssmtp.com header.b="oGgrJ/6N"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id C7CFC93D74; Tue, 26 Nov 2019 04:29:47 +1000 (AEST) Received: from mail-qk1-f182.google.com (mail-qk1-f182.google.com [209.85.222.182]) by minnie.tuhs.org (Postfix) with ESMTPS id E56BD93D71 for ; Tue, 26 Nov 2019 04:29:46 +1000 (AEST) Received: by mail-qk1-f182.google.com with SMTP id e187so13691982qkf.4 for ; Mon, 25 Nov 2019 10:29:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bsdimp-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=tapIF7TDSfVU34tHDumW0zc7WRNgHIUUEatMVBG/hQM=; b=oGgrJ/6NZWxnC9K52nYckfbNDSCWsnOoAZ7CauCEKqDluldjfwWBAayvaTkuX598sD VdmY3M8Yyf4Eb8QLtu6oUgx95SNYqm3l11Cwx7u7Sgo3uwIQ8TOQ8M0aPwcz93K9Nijx KT9Dgf7yXdrjD9HBPl/Xu8+/Zsyj7/bWWa4yzS1MGv33q91xPm+UX5uDDGaVpkbOx6Yc u5p1qeUPrN6vG7Ym6eoBMhH3cdV8L+E9msItDDooIstq6Ou6qjU4tgzx0N1HTLdSMDuD avA4RPukVYj7YAQfYnYgxIEjMKOUs4BBNKPrN6XQ4BcY5S64zp6gdhc/lu8o93b0OvC6 4V5A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=tapIF7TDSfVU34tHDumW0zc7WRNgHIUUEatMVBG/hQM=; b=pbtKp09Q7nktmrnpmgCAc5cjJkFGfDJUZevLsHSCyM20SNkd1gzusoYEAAnd9vc3GR TCqkNB/GQJlh9cEv0hE4sB4FdDGgqNkFAX7ztdLCZlrZVouluNuaqZYo3QW/ixtdPGvR ksCuwEcLyBIOTeW1jA+4jz0s+5VzsJF6oE+urSTtPzbLI3t9ToPJwM1RHTrcFkMfYMyy TaQgOoZI6KQIN1UBsiamvaQ/8T6VPifcbtLP+UzEJ6B7gSX4tw6/Sy+CL8D4HLCFt2K5 an+akBlxw1AzOCkBHDLcjRiJwnanZVbxJEQlONxinXNpM2XMbiiZiy1Mefc/7cZTDfgz f31g== X-Gm-Message-State: APjAAAVGkAbgfHzEQSs7ruH4PvjhRvPKxugvGlOzP+HPICCuq0ntKC9L 90pkqyAYz+yTob9VOLFqcRVoCdamNQfQSzRONQx231GN X-Google-Smtp-Source: APXvYqzOAy23ts4t5P/tx8XwjHePp8P6+8Y4mxtkY37uaL8vhLITB8HqfkjK8Q8QsiP/CH1jde7AYBBhM2J69NZhxy4= X-Received: by 2002:a37:7dc2:: with SMTP id y185mr17092520qkc.380.1574706585651; Mon, 25 Nov 2019 10:29:45 -0800 (PST) MIME-Version: 1.0 References: <20191124225239.GG18200@mcvoy.com> <20191125032404.GM18200@mcvoy.com> <0a6fb097-fe79-1633-0205-1c45f0a56953@bitsavers.org> In-Reply-To: <0a6fb097-fe79-1633-0205-1c45f0a56953@bitsavers.org> From: Warner Losh Date: Mon, 25 Nov 2019 11:29:34 -0700 Message-ID: To: Al Kossow Content-Type: multipart/alternative; boundary="000000000000a9e2fa05982ff236" Subject: Re: [TUHS] Someone wants to use an exabyte 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" --000000000000a9e2fa05982ff236 Content-Type: text/plain; charset="UTF-8" On Mon, Nov 25, 2019 at 10:07 AM Al Kossow wrote: > > > On 11/24/19 7:24 PM, Larry McVoy wrote: > > So that sounds like a different problem. People correct me if I'm > > wrong but the exabyte drives seemed to have a head alignment problem. > > They are 8mm helical-head drives. they wouldn't go out of alignment by > bumping them, the worse would be the tape would lose tension if you > smacked the tensioning arms hard enough > > They do have a lot of rubber parts inside. > Rollers crack and belts go soft. I have several dozen dead EX8200s from > that. > > I have a whole box of 8mm backup tapes that just came in, and a small > number of working drives. The Linux software I wrote to do 9 track tape > recovery > from a SCSI 9 track drive works just fine on an Exabyte. > > And I'm not offering to read Jason's mystery reels. > IIRC, the main issue from back in the day was different densities on the same form-factor tapes. So if you want to the same model 8mm drive, it works, if you go to a different (older?) model, it wouldn't. Eg, going from the 8500 -> 8200 caused problems due to data density issues. IIRC, you could write low density data tapes on the 8500 for interchange with the 8200, but it wasn't the default on some platforms? But it's been a long time and my memory is hazy... so long that Exabyte went bankrupt, several new tenants tried to rent the old space, the developer that bought it at the exabyte firesale wen bankrupt too and the new developers that bought it have torn down the old Exabyte offices in Boulder and replaced it with a set of luxury apartments... I could be misremembering... Warner --000000000000a9e2fa05982ff236 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


=
On Mon, Nov 25, 2019 at 10:07 AM Al K= ossow <aek@bitsavers.org> wr= ote:


On 11/24/19 7:24 PM, Larry McVoy wrote:
> So that sounds like a different problem.=C2=A0 People correct me if I&= #39;m
> wrong but the exabyte drives seemed to have a head alignment problem.<= br>
They are 8mm helical-head drives. they wouldn't go out of alignment by<= br> bumping them, the worse would be the tape would lose tension if you
smacked the tensioning arms hard enough

They do have a lot of rubber parts inside.
Rollers crack and belts go soft. I have several dozen dead EX8200s from tha= t.

I have a whole box of 8mm backup tapes that just came in, and a small
number of working drives. The Linux software I wrote to do 9 track tape rec= overy
from a SCSI 9 track drive works just fine on an Exabyte.

And I'm not offering to read Jason's mystery reels.

IIRC, the main issue from back in the day was differen= t densities on the same form-factor tapes. So if you want to the same model= 8mm drive, it works, if you go to a different (older?) model, it wouldn= 9;t. Eg, going from the 8500 -> 8200 caused problems due to data density= issues. IIRC, you could write low density data tapes on the 8500 for inter= change with the 8200, but it wasn't the default on some platforms?

But it's been a long time and my memory is hazy...= so long that Exabyte went bankrupt, several new tenants tried to rent the = old space, the developer that bought it at the exabyte firesale wen bankrup= t too and the new developers that bought it have torn down the old Exabyte = offices in Boulder and replaced it with a set of luxury apartments... I cou= ld be misremembering...

Warner
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