On Thu, 30 Sep 2004, Adrian Graham wrote: Thanks, all! -- Sellam Ismail Vintage Computer Festival ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org [ Old computing resources for business || Buy/Sell/Trade Vintage Computers ] [ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]

Zane H. Healy wrote: If the cartridges (note correct USian spelling) have a tape length printed on them that will tell you whether they're 1GB, 2GB, etc. Most DDS drives will read, if not write, older formats. IOW a DDS3 drive should rad a DDS1 tape. The bigger problem is whether hardware compression was used, and what Unix tools were used to create the tape - tar, cpio, dump - and those are just the common ones.... All the Unix standards allow TOC listing of an archive, which should tell you if you're using the right tool. DDS tapes have a write-protect as well, so if the tapes are in good shape, you ought to be able to do that non-destructively. I'd be inclined to do some futzing around with them first. A DDS1-3 drive will just spit the tape if it can't ID the media, and depending on the Unix in question, it's an odds-on bet that the archives were made with either tar or cpio. True, but the time-frame for these narrows the field considerably. Doc

Is there a non Usian spelling? Indeed. The thing not to do is put a DDS3 (or DDS2) DAT tape in a DDS1 drive. At least not if the drive is a TLZ04 since you will "significantly" degrade the head's lifetime. I never found out how significant "significant" is. The problem is that tapes longer than 60m were designed to be used on drives that wrapped them around the heads at a different angle, so the tapes are different. The difference is enough to wear the TLZ04 head much more than is acceptable. I do not know whether dropping a 120m tape (DDS3) into a TLZ06 (DDS2 drive) will have similar effects. So be careful out there! Antonio -- --------------- Antonio Carlini arcarlini(a)iee.org

----- Original Message ----- From: "Antonio Carlini" <a.carlini(a)ntlworld.com> To: "'General Discussion: On-Topic and Off-Topic Posts'" <cctalk(a)classiccmp.org> Sent: Thursday, September 30, 2004 3:54 PM Subject: RE: Need to know DDS drive used to write backup tapes DDS3 is 125M, 120M is DDS2 correct? DDS1 tapes are 90M

On Fri, 2004-10-01 at 00:11 +0100, Antonio Carlini wrote: 60M DDS tapes also exist though - I have quite a few on the shelf above me, made by various manafacturers. I believe any DDS-1 DAT drive will read/write 60 or 90M DDS tapes (that *may* vary by drive manufacturer though) - it's just that TLZ04's happen to be 60M but not DDS. 60M DDS tapes are 1.3GB, 90M DDS tapes are 2.0GB and 120M DDS-2 tapes are 4GB, IIRC. No idea about DDS-3; I've got one stray DDS-3 tape I think but no drive to put it in :-) Mine too. They self-destruct long before the head wears out :-) Always keep a backup DAT drive handy for your backup tapes... ;-) cheers Jules

On Thu, 30 Sep 2004, Zane H. Healy wrote: On that subject, can anyone shed light on what appears to be a common failure mode for DLT7000 drives? I have (2) which misbehave in the same manner. At powerup, the head recalibrates (bzzzzzttt), the door lock solenoid activates and the green LED on the bottom right lights. However, all the density and tape type LEDS on the left simply flash in sync approx. 2x per second. An inserted tape will load, but that's all she wrote. No track calibration, no shoeshine - nothing. Exact same symptoms on both units. One was working until the power was accidently interrupted in the midst of a backup. The second was a $5.00 swap-meet item picked up in the hope of yielding parts to get the first working <g>. Steve

A vote in favour of that suggestion: the TZ87 on my desk right now suffered the same symptoms, was fixed (by someone else) and the problem was precisely this. I'm told it is apparently quite common. Antonio -- --------------- Antonio Carlini arcarlini(a)iee.org

Interesting, I'd not considered trying to read them in a newer drive. I do know that about seven years ago I tried reading some with the DDS1 drives that we had at the time (they'd have been written on a DDS1 drive). The research I did at that time indicated that for a DDS1 tape, you *REALLY* need to know the type drive they were written on in order to read them, as one manufacturers DDS1 drive was likely to be incompatible with anothers. At this point, due to the value of the data on the tapes, I'm not sure I feel comfortable attempting to retrieve it, as I'm operating under the assumption that you have one try per tape, and this is with tapes that have been stored properly. Still the big thing is I simply don't have time to deal with the amount we have. Based on what I've seen, and what I've read on media longevity, the lifespan of a TK50 is considerably longer than a 8mm (8mm, has a two year lifespan, I'm not sure what the lifespan of 4mm tapes are). I've recovered data from TK50's that were 15+ years old. Zane

Trust me, you can't. If you had a genuine DEC drive, up through something like a TK87 or TK88 can read TK50 and TK70 tapes, but the equivalent Quantum drives can't. Most of the drives we have now can no longer read DLT III tapes, and the ones we'll be recieving in our next Library can't read DLT IV tapes from what I heard yesterday. Having said that, I collect old tape drives (and when possible old tapes so I can first test the drives), so people around here tend to eventually come to me when they need odd tapes read. Zane

The last DEC DLT drive to read the older formats was the TZ88, after that the head design changed with the TZ88N which could only read TZ87/8 tapes. Somewhere on usenet is a post by one of the DEC tape boffins explaining it all but he spoke in Oersteds and I kind of lost the plot :) SDLT by any chance? cheers w

On Thu, Sep 30, 2004 at 10:44:49AM -0700, Zane H. Healy wrote: If anyone has any "old" DLT-III or DLT-IV drives lying around, unloved, I can put them to use at home (here, we are using SDLTs and have deprecated older DLT formats except for the occasion we have to send data to someone that hasn't yet bought an SDLT drive). -ethan -- Ethan Dicks, A-130-S Current South Pole Weather at 30-Sep-2004 18:40 Z South Pole Station PSC 468 Box 400 Temp -61.3 F (-51.9 C) Windchill -106.1 F (-76.8 C) APO AP 96598 Wind 21.8 kts Grid 040 Barometer 676.5 mb (10760 ft) Ethan.Dicks(a)amanda.spole.gov http://penguincentral.com/penguincentral.html