On Fri, Mar 17, 2017 at 4:16 PM, Rich Alderson <[email protected]> wrote: >> From: Ethan Dicks <[email protected]> >> 2400' tapes (1.5mil thickness) were standard but sometime later, thinner (1.0 >> mil?) 3600' tapes came out.
> At LOTS (the Stanford academic computing facility where I worked from > 1984-91), > we did nightly incrementals and weekly full backups... > > On the -20s, weekly backups took up 3 2400' reels (only a small portion of the > 3rd reel being used). When Memorex came out with their 3600' tapes, I > switched > us over to using them so that weekly backups (rotated on a monthly basis) took > up less space; nightly incrementals used 2400' because it was almost unheard > of > fot need more than 1, and they were a sunk cost. Nice save there. I managed our wall of tape. I would definitely loved to have removed 20%-30%... > The 3600' tapes worked very nicely on TU78/TU79 drives and on the STC drives > on > the SC-30M, and I don't recall any complaints about them on the TU81s attached > to the VAXen. As operations manager, I would have heard. We had a TU78 as our big, main tape drive. It was really fiddly about autoload and we had DEC FS out a *lot* when it was under contract. After we couldn't afford to keep them and all the maintenance fell on me, I did what I could with it, and we did use it a lot, but there were some tapes that just would not play nice. We cleaned the glass and did all the things. Some tapes always worked. Some worked most of the time. A few just would not autoload. Once we could get a tape loaded and on BOT, the drive was fantastic. I never had enough data about brands, etc., to figure out the loading problem. Our TU80 was fine with whatever we put into it. I never had a single problem with the one from the office except after a year or so outside the data center (at my house), the vacuum pump became unhappy, due to, I think, high humidity in my non-air-conditioned house. The TS03 was a beast that shredded tapes if you did not do exactly the right things. I didn't use it much but a couple of our folks spent a lot of time swearing at it. >> I have read tape drive instructions that say not >> to use those tapes in this machine. I wouldn't be surprised if most DEC tape >> drives didn't like thinner tape. I _think_ the warning I recently read about 1mil tapes was in the manuals for a front-loader HP 7879 drive that I was working on last year (it passes most of its tests but is still a little cranky). Your experience with thin tapes is vastly greater than mine. Good to confirm DEC tape drives are solid. -ethan P.S. - that TU78 was one of the 4-5 items I could not save when the company folded. _______________________________________________ Simh mailing list [email protected] http://mailman.trailing-edge.com/mailman/listinfo/simh
