I do believe that ultimately, very little of our technology will be around for the museums in a couple hundred years--the plastics will all have deteriorated
https://www.ebay.com/itm/Rare-Vintage-IBM-DisplayWriter-Monitor-for-parts-or-repair/333888436598
as an example
I can't believe someone would try to sell this at all. $300 ????
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The problem with those "tape seal" strips is that they age badly. Get on toward 40-50 years and with many of them, the PVC strip turns brittle and breaks right at the hanger--the hook itself is fine. No way to repair those. About a year ago, I went on a search on the cctalk list for anyone who had a stock of the old tape seals to replace customer seals that were broken or missing. Only one person volunteered and ultimately was unable to deliver. Tape seals haven't been manufactured for a long time. The hard plastic ones used for IBM auto-load tape drives (can't recall the name) are quite a bit better, but even harder to come by.
I gave up finally and shipped the uncased tapes or those with broken reel strips back to the customers in plastic 800' 16mm film cans, which are still made and perfectly sized.
I do believe that ultimately, very little of our technology will be around for the museums in a couple hundred years--the plastics will all have deteriorated; the erasable semiconductor media (e.g. flash drive) will have dissipated its charge.
The same thing happened with floppies as well; from a nice box holding up to 10 to a poly bag of 50-100 stuffed into a simple cardboard box. The more interesting ones are the single-3.5" plastic containers.
I occasionally have to repair a tape reel, with broken flanges or even where the reel has separated. It can be done--and even a reel missing part of the flange can be read, if done carefully.
But I've found no repair for broken tape seals. I remember when every new reel of tape came in its own plastic clamshell container. Then the "tape seal" hangers came into vogue and those clamshells were discarded by the dumpster load. Too bad--some of them had a lot of thought put into the design. Was it Wright Line who first pushed the tape seal hangers? IBM, of course, had their own system.
Old tape canisters are interesting from a design standpoint. There are twist a catch, push a button, and pull a knob types. All done differently, I expect, to avoid patent issues. I've seen very few broken ones. I suspect that they accounted for a fair part of the cost of a reel of tape.
When the tape-seal thing came into vogue, the market opened up quite a bit. Instead of those expensive canisters, manufacturers could apply the very cheap seals and supply tapes by the pallet-load. with reels just wrapped in poly and stacked like poker chips.
The same thing happened with floppies as well; from a nice box holding up to 10 to a poly bag of 50-100 stuffed into a simple cardboard box. The more interesting ones are the single-3.5" plastic containers.
That is the "Easy-Load II" tape seal, designed to autoload in IBM (and compatible) drives. In retrospect, I'm surprised IBM didn't try enforcing a patent on that design. Maybe they didn't because of the anti-trust lawsuit?Note that the tape seals are the IBM type, so they probably survived pretty well.
That is the "Easy-Load II" tape seal, designed to autoload in IBM (and compatible) drives. In retrospect, I'm surprised IBM didn't try enforcing a patent on that design. Maybe they didn't because of the anti-trust lawsuit?
To bring this back full circle to DEC, the TU77/78/79 drives also "supported" Easy-Load II seals. By "supported", I mean that the drive knew how to open the seal and blow air through the seal, not that it could actually successfully auto-load. I had a relatively big business of fixing those drives while I was at SPC - people would drop off whole refrigerator-sized tape drives and I'd apply all of the ECOs/FCOs and perform all of the adjustments. By the time a drive left my shop, it would autoload flawlessly as well as run through a whole 2400' reel at 6250 without even a single soft retry. Once DEC heard about this, there was a stealth parade of drives coming in that were referred to me by the local Field Service office.
One trick with the Easy-Load II seals was that the end of the tape needed to be specially prepared - the cut end was rounded and some creases applied to make it easier for the vacuum to "pick" the free end. The DEC part number for the crimper was 47-00038-00, although you could get them from all of the "usual places" like INMAC. The DEC TSZ series drives and their Cipher counterparts would also benefit from having the tape ends crimped that way.
DEC trivia - the TU79 door has 3 small rectangular indents. Those are used to apply IBM channel and unit number (normally starting with 280) labels.
I was using "TU" as the generic, as the 77 only came in Massbus TU77, the 78 came in Massbus TU78 and STI TA78 flavors, and the 79 only came in STI TA79.Terry, were there really a TU79? I've only seen/heard/touched the TA79, which talked STI. A TU79 would, I assume, be the Massbus variant. I've used TU78, but it would be cool if the TU79 actually also existed.
Our TU77 and TU78 worked pretty well in picking up tape when autoloading, but they were far from perfect. Could maybe have used some of your tlc.
We actually still have those drives. I should try getting a TU77 running, as we don't have any running 800 drive at the moment.