From nobody Wed May 25 10:52:55 2022 X-Original-To: freebsd-questions@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id D44B01B4F745 for ; Wed, 25 May 2022 10:53:05 +0000 (UTC) (envelope-from freebsd@edvax.de) Received: from mout.kundenserver.de (mout.kundenserver.de [217.72.192.73]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "mout.kundenserver.de", Issuer "TeleSec ServerPass Class 2 CA" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4L7Sb44HW5z4mn2 for ; Wed, 25 May 2022 10:53:04 +0000 (UTC) (envelope-from freebsd@edvax.de) Received: from r56.edvax.de ([94.222.6.39]) by mrelayeu.kundenserver.de (mreue109 [212.227.15.183]) with ESMTPA (Nemesis) id 1MYeV3-1oOSU72ypv-00VfDC; Wed, 25 May 2022 12:52:56 +0200 Date: Wed, 25 May 2022 12:52:55 +0200 From: Polytropon To: "Kevin P. Neal" Cc: "Steve O'Hara-Smith" , freebsd-questions@FreeBSD.org Subject: Re: Tape, was Single User Message-Id: <20220525125255.10b45abf.freebsd@edvax.de> In-Reply-To: References: <24632e11-1a86-8553-cf44-d29aa40a6858@kicp.uchicago.edu> <20220519223448.e1db4297aef551734852e4fd@sohara.org> Reply-To: Polytropon Organization: EDVAX X-Mailer: Sylpheed 3.1.1 (GTK+ 2.24.5; i386-portbld-freebsd8.2) List-Id: User questions List-Archive: https://lists.freebsd.org/archives/freebsd-questions List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-questions@freebsd.org X-BeenThere: freebsd-questions@freebsd.org Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Provags-ID: V03:K1:tbF2oQE0Gzf6ut9GFowECiIbWZDvkOL+rXpULiWRoxZBWVAZ94h LF5gQj20KlNml3rrSQWLOAW2e3XfOM3xUWd3cxxYcBjG7FpBNMLcK4Ci6XNF/uCyvBI8yrM 1xuRjvsoX7MXWRzFhOxGQdl1dk7lKU+UUMZ2w63a7wyhMp96dZT4KxXwRbpGdYVdvfLPUfk 5NC8+aiRnxJ8wLyrjPD4w== X-Spam-Flag: NO X-UI-Out-Filterresults: notjunk:1;V03:K0:sVHRxnvAcEA=:4ddZsQ7itQ7HVonyr8dHPv oJ8Z7B8X13+75tjLwBG8RU4rqcm5g/1jo2hfnpFo68/P6vF5k/xW7uHYAF+k7Mb28FMdpURBh pa0nKyT/ztlIf08GlOb12GBvGyMN2Q9Tfo+dyYJqJSGvVOlo+jGHnEKdtIXkGeyRVsFyHJeHM yVtlVwqRNp4yhkC94zI7+Azl4fkl9XANpmC3u4zdmw+BEH7/BIfyO1ETHU1Opi2c1tMivm9BK YtMGDSyujxEwfsEkKjn3ozd+Uu49amODQPsQPVYLAuKROuvD3CcDdMrUGHKUTTQNUdqjvDGGd ES+BCaYa2tAN0aIZS/gQ2qOa6S9C0UKBILtDERabCRH7RnE3r5wacONoG0MNfYj38YxmS3+c+ uL7GeMdepEI9yBbGt0xL6CZU+EqrtpO0LFgxp8HKe9kXyvqXaHRJ+q0OW5Z35/uIIb9VbOOSD MsuW+GkXN2Pqa70o5Enp2wg/QUn3Yhox8VpX0jr/XS11PacadZlsTlpDajOqlK5qdhYErq2qU g3hdfb7KbWcNSN5bnCmpc/CsqbShRD1I4/YQYsztrHokoZ/MGtxL2T0Yef5L9yxnJpc9moYJ9 CxZP+w6ONK8euskhFkhotucMNeP7Gc6xGK6JsLISK8DU7RXU8knqm2MwPn1LXcfVy2wLylzO2 E7fCDWMeOUMgharBcGyfqaCFdOxOoThC4hEz0OC/JwR5I9ByRFjv9DEZHqEV1eXDTUteHHk7/ y2W9zkAHuFG0FetqytzofW/ojextLcebN8LAGA== X-Rspamd-Queue-Id: 4L7Sb44HW5z4mn2 X-Spamd-Bar: + Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=none (mx1.freebsd.org: domain of freebsd@edvax.de has no SPF policy when checking 217.72.192.73) smtp.mailfrom=freebsd@edvax.de X-Spamd-Result: default: False [1.08 / 15.00]; HAS_REPLYTO(0.00)[freebsd@edvax.de]; RCVD_VIA_SMTP_AUTH(0.00)[]; TO_DN_SOME(0.00)[]; MV_CASE(0.50)[]; HAS_ORG_HEADER(0.00)[]; RECEIVED_SPAMHAUS_PBL(0.00)[94.222.6.39:received]; RCVD_TLS_LAST(0.00)[]; R_DKIM_NA(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:8560, ipnet:217.72.192.0/20, country:DE]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; REPLYTO_EQ_FROM(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; NEURAL_SPAM_SHORT(0.68)[0.682]; NEURAL_HAM_LONG(-1.00)[-1.000]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[edvax.de]; AUTH_NA(1.00)[]; TO_MATCH_ENVRCPT_SOME(0.00)[]; MID_CONTAINS_FROM(1.00)[]; RCVD_IN_DNSWL_NONE(0.00)[217.72.192.73:from]; MLMMJ_DEST(0.00)[freebsd-questions]; R_SPF_NA(0.00)[no SPF record]; RWL_MAILSPIKE_POSSIBLE(0.00)[217.72.192.73:from]; RCVD_COUNT_TWO(0.00)[2] X-ThisMailContainsUnwantedMimeParts: N On Tue, 24 May 2022 20:56:58 -0400, Kevin P. Neal wrote: > On Thu, May 19, 2022 at 10:34:48PM +0100, Steve O'Hara-Smith wrote: > > On 19 May 2022 20:49:51 -0000 > > "John Levine" wrote: > > > > > The thing in the picture isn't paper tape, it's a 1/2" magnetic tape. > > > It looks relatively new, 1970s rather than 1950s so it is likely > > > recorded 9 bits across (8 plus parity) at a density of 1600 or 6250 BPI. > > > > I didn't look at the picture. That could be a *lot* harder to read > > even if you have a drive. I've heard tell of tapes that could only be read > > once due to storage damage rendering them more than a little fragile. > > Oh, no, did data tapes also have this problem? The problems with Ampex 456 > in a certain range of time are well known. I've seen it called "sticky > shed". Seems to depend... I have ome (!) audio tape that has had "dry loss" of magnetic material (not sticky, only crumbs), but I also have a data tape ORWO Typ 430 (6250 bpi) probably from the early 1980s that is still in mechaincally perfect condition. Maybe there are "bad batches" of tape just as it were with floppy disks (BASF), optical discs (EMTEC) and hard disks (IBM DTLA) with this specific kind of problem? IEF280E K 3D0,1069SS,LICHTAUS,ANALYSE2 IGF991E MOUNT PENDING FOR DEVICE 3D0,SER=1070SS IEF403I SVDRUCK STARTED TIME=10.58.35 ;-) -- Polytropon Magdeburg, Germany Happy FreeBSD user since 4.0 Andra moi ennepe, Mousa, ...