From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-3.6 required=5.0 tests=MAILING_LIST_MULTI, NICE_REPLY_A autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 22072 invoked from network); 27 Nov 2021 17:44:47 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 27 Nov 2021 17:44:47 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id BCD109CEB1; Sun, 28 Nov 2021 03:44:42 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 33F739CE5D; Sun, 28 Nov 2021 03:44:08 +1000 (AEST) Received: by minnie.tuhs.org (Postfix, from userid 112) id E0C7E9CE5D; Sun, 28 Nov 2021 03:42:10 +1000 (AEST) Received: from relay11.mail.gandi.net (relay11.mail.gandi.net [217.70.178.231]) by minnie.tuhs.org (Postfix) with ESMTPS id 056C294942 for ; Sun, 28 Nov 2021 03:42:09 +1000 (AEST) Received: (Authenticated sender: aek@bitsavers.org) by relay11.mail.gandi.net (Postfix) with ESMTPSA id B65FE100004 for ; Sat, 27 Nov 2021 17:42:07 +0000 (UTC) From: Al Kossow To: tuhs@minnie.tuhs.org References: <20211127152527.591D518C07B@mercury.lcs.mit.edu> <1ae0c3f8-fc2b-84a9-442b-e591dca591fd@technologists.com> Message-ID: <90aef905-c7c2-9856-5dd7-3f736666ddb0@bitsavers.org> Date: Sat, 27 Nov 2021 09:42:05 -0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [TUHS] tape "baking" [was PL/I stuff - was: Book Recommendation 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: , Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" On 11/27/21 9:39 AM, Al Kossow wrote: > On 11/27/21 8:07 AM, Steve Nickolas wrote: > >>> Ampex patent 5,236,790 says 54C for 16 hours. > > There are a few other tricks, like forcing air through the tape during baking > that we came up with in the 00s. There are others, like using 32 track 3490 MR > head stacks for recovery. > https://patents.google.com/patent/CA2817359A1