barrett@jhunix.HCF.JHU.EDU (Dan Barrett) (05/07/91)
Thanks to everybody who mailed a response to my question: "What media will be readable in 25 years?" Enclosed is a summary of the responses. (Actually, many responses were kept intact because they are interesting, so it's not much of a "summary". :-)) If you recall, I asked this question because we are making a "time capsule" that will be filled with disks/recordings/etc and then opened in 25 years. Guess what? This article (with all your helpful responses) is going to be placed in the capsule too! You are now all famous. :-) It should be very interesting reading in 25 years. Incidentally, this is being done by the computer music department at the Peabody Conservatory of Music in Baltimore, Maryland (USA). COMMON SUGGESTIONS Include not only the media, but a device for reading it (Walkman with batteries, turntable, etc.) Use acid-free paper. Magnetic media probably won't last 25 years. Isn't 25 years an awfully short time? [My answer: no, not in the computer and computer/music industry.] TALLY Here is a tally of the votes; 31 people responded. Note: some responses did not give an easily-discernable "yes/no" answer, so my tally may be slightly wrong. Computer: Optical media: 10 Hardcopy (acid-free): 5 Punch cards: 5 OCR/barcodes: 4 3.5" disk: 3 9-track tape: 2 5.25" disk: 1 Hard drive: 1 4mm: 1 Vinyl record (!!): 1 Audio: vinyl record: 13 CD: 8 cassette tape: 7 reel-to-reel: 5 VHS: 4 Laserdisk: 1 DAT: 0 Other: Microfiche/microfilm: 2 =========================================================================== From: new@ee.udel.edu >For music: Why not include a bunch of cassetts *and* a cassett player (and specs on the required power supply and output levels, from which interfaces could be built). Of course, this assumes that the medium will last 25 years in storage. I'm not addressing this part; I mention cassetts only because cassett players are cheap. >For computers: Good ol' hardcopy never let me down yet :-) 'Course, it's a bit of a pain to type back in again, but if it's really important, you should probably include a hardcopy, just in case. One choice would be to pick something that *lots* of *big* industries use now or for which an interface could be cheap to build and easy to describe. OCR (like on checks) and barcodes both leap to mind. Low density, but if it's important, it could be scanned in. It depends to a great extent how much data you are talking about archiving. =========================================================================== From: The Friend <amigo@milton.u.washington.edu> Whatever media holds the most data in the smallest space would be the best answer. I'd definitely stand behind 3.5" extra-hidensity disks, which keep packing more data in the same space (2.8 megs now). 5 1/4" is going the way 8" disks did - every machine has a 3.5" drive availible, so there's no reason to hold 5 1/4" out that long. Optical discs & _CDs_ believe it or not - I think they'll be doing some revamps on CDs eventually - double-siding them for albums that require it is easy. By then CDs will be writeable, and they are now writeable (though expensive at the moment) on computers. VHS will be here for a long time to come, though writeable Laserdiscs will probably be around at least by then. Cassette will stick around for some time - though probably much like vinyl is today. Vinyl itself will be a novelty item by then - with very few players around (none produced anymore). DAT isn't catching on, and probably won't - people want writeable CDs, not another tape format! So, the list: 1> CDs - they'll be a multi-format player that plays what will be the "old" standard, and the new standard reads&writes. 2> Laserdiscs - I know, you forgot to include it..but it will be very popular soon. 3> VHS - a Hi-Fi/Super VHS VCR is just a great picture, it records, and sounds excellent (the best any analog recorder has done). ------ Computer media: 1> CD-ROM/CD-WRITE [or whatever it'll be called by then] - CD ROM is spreading fast/developming heavily in the PC marketplace, so it'll no doubt be a leading force by then (course this is based on a affordable writeable disc comming out). 2> 3.5" discs - they'll continue to cram more on 3.5" as track density increases (one test already had 10 megs on a 3.5"). 3.5" are great because they're rugged & self-contained. (A 2.0" disc has been introduced, but its only being used in _some_ portables hi-density is possible, though since 3.5" is already popular, I don't see it becomming a major disc format). =========================================================================== From: mfineman@cadev6.intel.com (Mark Fineman ~) >cassette tape? marginal. Not 100 years >vinyl record? essentially certain for 25 years. May have much longer life >DAT? marginal. Not 100 years >VHS? marginal. Not 100 years >reel-to-reel? marginal. Not 100 years >CD? probably. May have much longer life, but unknown. It also costs under $2000 to make master and limited copies, so may be an option. I would include devices for reading and instructions for reading (playback). Vinyl record have the easiest to make technology. >For computers: I'd go with optical disk and 4mm, again with instructions for technology to playback. Also: ASCII only data, one file per file. Also to both: The instructions should be on low acid paper, etc. + silver microfilm (as compared to azoid or thermal microfilm) There are well documented ways of treating the silver film to last 100+ years. In fact, if you assume a technology that can scan digitized data on images (which we had for under $10K before 1967), just put decoding information at the start of a microfiche and digitize everything else onto the microfiche. You can probably get a COM (computer output microfiche) place to do this for you. Alternatively, send output to lazer printer and rent a camera to make microfilm of it. You are correct that some technologies are essentially lost (7 track magtapes even more so than 8" floppies.) =========================================================================== From: Stephen M. Smith <smsmith@hpuxa.acs.ohio-state.edu> I would stay away from magnetic media if possible. One atomic bomb's magnetic field could too easily erase everything... ;) My hunch is that optical would be best. How about one of the new removable optical disks? With the right software you could use it for either music or computer/text data. =========================================================================== From: scarfone@cs.Buffalo.EDU (Steve Scarfone) Punch cards. :-( I'd be interested in knowing what other people think about this. Would you be willing to post a summary? =========================================================================== From: abennett@ATHENA.MIT.EDU There are CD makers around (one in Plymouth, I believe) that could probably make A CD for you. Otherwise, use DAT - it's becoming the international standard (they've been in Europe for years already) and even if DAT falls by the wayside, it can be read by a computer if necessary (it's binary) and re-translated (a specialized reader is not required, you can always remove the tape and mount it on whatever reel/deck size is in vogue). Of course, the odds of *anything* of a magnetic media type still being useable after 25 years is a bit chancey. I wouldn't risk it myself. Your best bet is printing it out on paper in some format that can be read by an optical scanner later. I think the UPC bar-code standard (like you see on packages in the grocery store) is your best bet. It's so wide spread (global), and it's so cheap... Ditto for computer stuff. Print it out on archival bond paper (ASCII, Hex, whatever). As time goes on, the only sure thing is OCR. There will *always* be stuff someone wants scanned in, so you can always count on good 'ol paper. =========================================================================== From: chuck@mrcnext.cso.uiuc.edu (charles bridgeland) believe it or not, this is a live question among librarian types. i have talked occationally over the years about this with bill henderson, univ of illinois' preservation specialist. in his opinion the big problem will be having the equipment available that can read the stuff. we already have this problem. there are nasa computer records from the sixties than cannot be read, and census data that is unavailable for this reason. he also regards lifetime claims as wildly optomistic. CDs? count on 10 years max, after that? magnetics decay with time. there are already reports of CDs that are unreadable, or delaminated. so, paper is prob best (acid free naturally--another thing this guy told me is that it is actually cheaper to manufacture acid free paper now, but that it is still a specialty item, and thus more expensive (and just _try_ to find acid free pin feed paper)). microfilm is also good. audio recordings? vinyl just sits there. ionclude a turntable and there ought to be something that it could be hooked to in 25 years. =========================================================================== From: krj@convex.cl.msu.edu (Ken Josenhans) LP should be readable as long as there are lots of baby boomers around -- all you need is 1 phono cartridge company somewhere in the world. Turntables are pretty easy to keep going, cannibalize junkers for parts. I expect LP to be readable for my lifetime. Maybe I just can't face the prospect of 1500 unplayable LPs in my collection... Anyway, LP has a big installed base and lots of dedicated users, and it's also important as an archival format for music recorded from 1950-1985 in both the pop and classical format. Cassette is in even better shape than LP, because cassettes are going to remain the medium of choice in the third world for a long time. Their cheapness is a big asset. And like LPs, they have a big installed base. I expect DAT to fail in the general marketplace, though it may survive as a niche product for home studio folks. I don't think it offers enough advantages to the analog cassette consumers to get them to switch. So I wouldn't bet on DAT being readable. VHS I would guess as marginal. There's a big installed base, but the tapes are somewhat fragile, and if a new TV standard comes along VHS could get swept into the dustbin pretty quickly. I don't think people have the same attachment to their VHS libraries that they have to their LP and CD libraries. 1/4 inch reel to reel will probably be difficult or impossible to read in 25 years, though again the technology is simple enough that I think dedicated nuts will be able to keep a few machines going. Professional reel-to-reel gear will probably still be around because there is such an immense library of recorded masters for it -- these masters represent some part of the worth of the big record companies. I expect CD to still be readable because I think it will still command a sizable share of the market in 25 years, though it may be coming to the end of its life. I dunno what replaces it; chips maybe. All this is IMHO, of course, but it's fun to speculate. =========================================================================== From: ac999321@umbc5.umbc.edu (ac999321) Your posting brings some interesting thoughts to mind. It seems to me that the most valid media to use should be not what is the most popular, or likely to be the most popular, as we both should realize how well the marketing people are able to make popular something which does not technically merit such status. In my opinion, the type of media used should be whatever is the most durable, however, thanks to the marketing types, this may very well be impossible since the goal of marketers is to push the newest, no matter how lousy, and also to push old, sometimes more reliable, equipment onto the scrap heap. Note that I'm most definitely not against new equipment/technology; a lot of it is great; however, we needn't abandon the tried and proven. Some sort of standard is an absolute necessity, unless society is to forge ahead and abandon the past, and all information and data that goes with it. Enough philosophy :-) It seems to me that an article that I read awhile back stated that one of the most reliable mediums of magnetic data storage was 9-track tapes. However, like any other magnetic media, all it needs is a good zap of magnetism or static electricity, and all is lost. Speaking of this, I have several audio cassettes which are about 10 years old; although the material on them is still audiable, the quality of the recording has degraded; the tapes have not been subjected to strong magnetic fields or stored near electric cables, etc. As to compact disks, I understand that they may be subject to something termed "CD Rot"; in some aging tests performed by several laboratories, both in the U.S. and Japan, they have proved that CD's are not as durable as some would like to believe. The plastic coating on them can deteriorate after a period ranging from 7 to 15 years or so, allowing for oxidization of the disk's metal surface. I'll admit that LP's are far from perfect, but they have been around for a l-o-n-g time (I have vynil ones going back to the mid 1960's and some old 78 RPM records going back to the 1950's); if handled properly, they seem to be a very durable means of archiving things.... now if they could just be made out of a more durable material (which won't melt, scratch, break, rust, disintegrate, or be attacked by mildew.... a possible problem which records placed in a dark time-capsule coud face, if any moisture is present). It seems that it might also be a good idea to find out what types of magnetic computer media are the most durable; it seems to me that lower density recordings would be more durable than high density recordings for both tapes and disks. As you mentioned, 8" disks are becoming more and more rare, but, in my opinion, they seem to be more durable than the new 3-1/2" mini-diskettes (errors seem to be more common using them); again, this could have something to do with the density of the recording medium and also with how well the media itself is able to retain the data (I forget what the correct terminology for this is, but it would be a lot more beneficial if the manufactures were required by law to print the technical specs for magnetic media on the cartons or boxes it comes in, as well as in their advertisements; the "100% certification - money back" advertising that they use is totally useless propaganda, in my opinion; I'd like to be able to make valid comparisons when I buy magnetic media; the data being saved is what is important, not the trivial refund. As to punch cards... hmmmm that's an idea :-), however, they should be made of acid-free paper so as not to decompose too rapidly; a real problem with some books reaching ages from 30 to 100+ years in my library. Alright, enough of my ranting and raving; hopefully some of the above information will prove useful to you. BTW, no flaming intended, isn't 25 years still sort of a short period of time? Best of luck on finding the answers that you're looking for; is this for some sort of project? If so, good luck with it; it would be interesting to find out the results; could you post a summary? I'd sure a lot of people will be interested. =========================================================================== From: Jerry <jpenne@ee.ualberta.ca> If I were going to make a "time box" I would use a cassette tape, plop in a cheap walkman, some rechargeable batteries, and a recharger. The thing least likely to change in 25 years is 120V AC outlets. Of course, you could always use a DAT and a player, but the above items are cheap now, making your time capsule a lot cheaper. For the computer, that's a little tougher. Depends on how big your box is going to be. A laptop would be nice. Personally, I couldn't see "throwing away" a laptop just for the future. But if money wasn't a problem that would be my suggestion. Again, it's rechargeable from a source that is likely to be around in 25 years. Another option would be to buy a cheap older computer like a commodore 64 or apple II or ibm pc for next to nothing and store some stuff on a disk for those. But these last few items would take up a lot of space especially for the monitor. *Hopefully*, it 25 years, NTSC video will be history. :-) =========================================================================== From: rshapiro@arris.com (Richard Shapiro) No tape format will be fully reliable; on the other hand, an untouched vinyl lp will be essentially perfect after 25 years. I've owned some records for 25 years and played them regularly; they're slightly warn (due to the poor turntables I used to use) but otherwise sound fine. Vinyl is definitely the most (proven) reliable long-term storage medium. But, if you can't use cd for the reasons you say, you probably can't use vinyl either. In which case, your best bet is probably analog reel-to-reel. >For computers: Actually, cards are the most reliable, though I doubt you'll find a working card reader in 25 years time; you may not be able to find a card punch even now. Digital tape can fail after 10 years of storage (I've seen it); magnetic discs are better, but any magnetic medium will fail over time. Optical disc is a gamble, but is likely to be the safest realistic (ie non punch-card) option. =========================================================================== From: Dave Sill <de5@de5.ctd.ornl.gov> Clearly, vinyl is the most durable medium, both in the stability of the medium itself (probably good for thousands of years) and in the longevity of the format itself. I'm a CD person, myself, but many true audiophiles still claim vinyl is sonically superior. CD would be my second choice, because it's the "permanent" medium of choice today and isn't likely to be supplanted soon. Physically, OD (CD-ROM moreso than magneto-optical) would be the most durable. Whether today's optical formats will be compatible in 25 years is a better question, though. I think CD-ROM will probably be around for a while since it's got mass-market acceptance in the PC world. Magneto-optical formats will likely change, though, as the technology improves. In magnetic media, 9-track is probably your choice. It's a low-density format, unlike DAT or Exabyte, so could suffer some loss and still be readable. And 9-track drives have been around nearly 30 years already. ...how long do magnetic tapes last before they lose their encoding or become too brittle to use? I don't know, but I'd guess 20 years would be pushing it. =========================================================================== From: rjc@cstr.edinburgh.ac.uk For music it's easy, vinyl can be played back with a pin and a piece of paper. Reel to reel is a good second bet. For computers, things are a little wierder. I am stronly tempted to say paper tape for the same reason as for vinyl above. A more difficult problem is encoding it. Computer hardware may be so different then that any idea of saving the software is silly, so you are best off with a vrey low key encoding, eg for pictures just lots of pixel values, no compression. Of course you could put some hardware in the box with the stuff. A walkman with batteries guaranteed to still be working then and a laptop PC. Of course Cassettes don't last well, so the walkie is probably out. =========================================================================== From: pdbourke@ccu1.aukuni.ac.nz 25 is a long time for technology. I would imagine that to be sure, whatever media you choose you should also provide complete playback hardware. This way all you are assuming is that electricity will be available! My vote for music: vinyl record (plus record player and instructions) My vote for computers: Optical disk (plus computer and optical disk drive) =========================================================================== From: Chris Sherman <sherman@unx.sas.com> >cassette tape? Yes. It is easy to use, durable, and very very common. 150 Billion walkman's can't be wrong. >vinyl record? Possibly, but in the hands of fanatics. Vinyl is hard to use, and deteriorates. Also, there is no good way to record to it. >DAT? DAT is not common, and I don't think it will be. R/W'able disks will be coming out soon, so the advantage of DAT will no longer exist. It may take off, but there is no good, solid reason for it. It doesn't really offer anything new to the common person. A common person can record on cas. tape, so what do you need a DAT for? >VHS? Yes. But VHS might get competition from writable laser disks in the years to come. VHS will probably make it to 25 years, but barely. VHS is easy to use, durable, and very very common. VCR's don't wear out very fast, either. Though not many people record (or know how too), therefore the disk may come in quickly once their prices fall. And cheap, writable disk will cause a steady conversion to disk as people replace their old VHS. >reel-to-reel? Cult object. For use by those who really want the best, whether they can hear it or not. R2R is clumsy, hard to use, non-portable, and benefits are small to the common person. >CD? We have NeXT's here on which we can record music sampled at 44.1 at 16 bit (just like a cd), but in a different format that only the NeXT's software understands. A cheap disk record will probably be available within 5 years, and then say by-by to DAT. I also see a holographic media in the future, something like a thin film that can be read by a scanning laser. Who knows, but it would be able to store a lot of info in a 3d space. >For computers: Standards in computers??? Hahahahahaha. Yeah right. Everything changes from year to year. Just 8 years ago, floppies on 64K machines was the in thing. Just 12 years ago, I could fit everything I could get or want onto one 143K floppy. And computer turnover is high; at least now it is. For the household, I don't think that there will be a significant increase in computer sales, unless somebody comes out with a good home machine (something that does not exist yet AT ALL). Someday, someone will come up with the Nintendo for running the house. It will be what the Atari 2600 did for home games. Nintendo is simply computer games, but done well. >3.5" disk? For which computer? They are common, cheap and durable. They may last 10 years. >5.25" disk? They are common, really cheap, but not very durable (relatively speaking). They will no longer be useful (in business) in about -2 years. >9-track tape? tar? When IBM dies, 9 track will die. Need I say more? >Punch cards? :-) One day, someone is going to come out with a card (holographic maybe) that will contain Billions and Billions of Megabytes, but a punch card, Naww... >Optical disk? Optical... Yes. Disk... Maybe. A spinning disk is bad. You want to be able to get to any part of the media instantly. Hard disks are fast, yes, but I think someone will come up with a way to get to data quickly, and with no moving parts (or at least not big moving parts, like a disk). In general, the things that will last are 1) small, but not too small 2) fast, but with few moving parts 3) reliable, and hard to break 4) common, whether the technology is stupid or not. (9 track) 5) endorsed, IBM (9 track, again) and some smaller reasons may be 6) fun, amazing, neat to look at, sexy (like optical disks) 7) powerful, but that goes without saying 8) cheap, but business' like to by technology because they think that will make people better. Yeah right. So cheap applies more to the home front. Also I see central location of data to become more common. Walking around with actual media in your hands may someday be rare. For instance, I haven't touched a disk in a long time, due to the fact that school (NCSU) is on the internet, and I can pass files around (ftp or mail) without use of media. NCSU itself keeps almost everyone's work on harddrives on the servers. I do touch exobytes, because I take care of the backups. But my job is not normal in terms of what a common computer user does anyway. Anyway, these are my humble thoughts... Care to flame me about any of these? I don't mind a good discourse, accompanied by node-to-node rocket fire. =========================================================================== From: peter@ficc.ferranti.com (Peter da Silva) >For music: vinyl record. (or CD. Actually, it's about as cheap to cut a CD as a record these days) >For computers: vinyl record. (really! again, or CD) Why? Because the information is stored mechanically. =========================================================================== From: lev@suned1.Nswses.Navy.Mil (Lloyd E Vancil) I would opt for Optical storage medium, and if you were serious about the whole thing put the device to "read" it in there too. 25 years is a lifetime to a man, an eterinty to technology, and just about enough time to travel to Alpha Centuri-3... ;-] =========================================================================== From: dwells@fits.CX.NRAO.EDU (Don Wells) You are asking a *really* fundamental question. I myself have thought a lot about it, because it is a critical issue for the design of large-scale, long-term data archives. I am in the process of designing such an archive for the Very Long Baseline Array project. >cassette tape? The media and magnetic signals will be mostly OK, but audio will be all digital by then, so players will be rare. >vinyl record? The medium will survive, but players will be rare, because almost all interesting historical material will exist in digital form by then. >DAT? The signal encoding is essentially optimal, except for the possibility of compression, and so it will probably still be compatible, and the media will have survived mostly (I suspect), but it is unlikely that the players will be still be common. >VHS? Yes, VHS will probably still work, basically on grounds that NTSC/PAL/SECAM video will still be in operation, even though some form of HDTV is inevitably going to be dominant by then. >reel-to-reel? Forget it. Already 1/4-inch r-t-r decks are uncommon. Mine is electrically still functional, but its rubber parts need to be refurbished, so it won't rewind. >CD? The medium will still be just fine. I therefore expect that players will still exist, and will be about as common as vinyl record players are today. >For computers >3.5" disk? For which computer? NO. >5.25" disk? NO. >9-track tape? tar? NO. Already 9tk decks are getting uncommon. >Punch cards? :-) NO. I last saw a reader in December 1985. >Optical disk? NO. The medium will be just fine, probably, but the march of technology in computer peripherals is merciless. CD-ROMs may still be readable (i.e., drives may still exist), but don't bet too much on it. Sigh... As I said, the march of technology is merciless. The advent of CDs has killed the old media (new vinyl records simply are not being manufactured today) --- but has not killed the old information! I recently purchased some CDs of early operatic singers. I have been purchasing CDs of old Lipatti and Gould recordings. Now that these old recordings are in a standard digital form they can survive *FOREVER*, migrating from medium to medium over the decades and even centuries. The implications of this are that long-term planning must include provision for migration of information from medium to medium. Format standards are important. For my VLBA archive I am most interested in casting my data into a canonical medium-independent form, and in building automatic utilities to facilitate the copying process. =========================================================================== From: jtb@iotm.ttank.com (John P. Gibbons) For one thing you CAN write to CD's, it just costs a little nowadays.. But being realistic, just put a tape player in the "Time box" along with the tape.. That would solve the problem.. I don't think putting a computer in the time box would be a good idea :-) So you would be best to go with 3.5" ibm compatible disks, for SURE someone will have an IBM compat. in there basement in 25 years.. After all there are trillion's of those suckers out there.. >Not many 8" floppy disk drives are available for PC's these days; >only 10 short years ago.... But they DO exist, and if you wanted one bad enough you could get one.. =========================================================================== From: dick@smith.chi.il.us Don't try to use magtape... seems to me that unless it's rewound every few years, it starts to get "print-thru" between the layers... and that causes errors. I recall reading (in risks...?) that some old NASA data has been lost this way. In 25 years, it might be unreadable. Not sure if this is worse for music or data, but someone may know. It's worse for thinner tape. I worked a while ago for Bell & Howell, on microfilm stuff... one of the concerns with the new user-writable optical disk media is the possibility that it might not be archival either. It seems that one writes the media by burning holes or pits in a substrate... it's possible that the burned-out material might drift back to fill in the holes after time. The last conference I attended on this stuff (about 5 years ago), nobody knew yet! This wouldn't be a problem with CDs, but you've rejected that. This is an interesting problem. =========================================================================== From: "J. Eric Townsend" <JET@UH.EDU> Most readable audio: >reel-to-reel? This technology is so solid it's not even funny. It'll probably be a mainstay of communications in many underdeveloped countries for years to come, just because there's so much "used" equipment for pennies, if not free. >For computers: A hard-drive with a straightfoward control mechanism: no funny high-performance drives, butsomething really widespread like SCSI. >Not many 8" floppy disk drives are available for PC's these days; >only 10 short years ago.... If you want 8" floppy drives for S100 based systems, they can be found for as little as $20. There are still plenty of CP/M machines around as well (I have more than one friend who *still* uses them as word processors and smart-terminals). =========================================================================== From: NANCHEN@uni2a.unige.ch In both questions (music and computers), the communication means that will probably last for a long time is the same that the one that has already lasted till today: magnetic tapes, probably. I don't know really the name in english of it, but not the small cassette tapes, you can play on your radio or walkman, but the rather old (20, 30, 40 years) magnetig tapes of half an inch wide! This means will surely last for the coming century. But, of course, it's not very commercial... I don't know why your interested in this, but you might prefer a more 'sellable' means, like 3.5" disks or cassette tapes. =========================================================================== From: Mark O. Chadwick <ncc1701@rpi.edu> Well, CD could be [recordable]. After all, there ARE recordable CD machines coming out on the market now. Reel-to-reel is already on its way out, as are vinyl records. I suspect that there will be something completely different being used as a medium by that point. [Music....] Here, too, I would have to throw my lot in with optical disks, for the aforementioned reasons...There are optical drives out now, although they are quite expensive. >...the newest technologies (optical disks, for example) have been around >only a short time; perhaps they'll be totally obsolete later, and the older >stuff (reel-to-reel tape) abundant enough to justify keeping >tape-players/readers around. On the contrary. Although they might only last, say, 10 years, it'll be much easier in _25_ years to get something to read media from 15 years ago (at that time) than to read something that is on its way out TODAY. I suspect that just about ANYTHING dealing with tape, with the possible exception of DAT/Video, will be long obsolete in 25 years. If the rewritable optical drives and disks drop enough in price,which they probably will, then ALL tape-based media will be gone. Remember, too, that most tape will not hold data for 25 years very well.. (that goes for magnetic disks, too). So, if you were to put such into say, a time capsule, whatever they dig up in 25 years might be unreadable/ deteriorated enough to make it all but useless... =========================================================================== From: Wes Morgan <morgan@ms.uky.edu> >music... Hey, make all of them! Just make sure that the same music is on each one. >computers... Why not include them all, with identical data on each? Explain in hard copy that these were the various media used for data in this time period. Give rudimentary explanations of each format, in case something has truly become extinct. I think that, for the computer version, the IBM PC format would be best; logic dictates that one of the millions of PC/clones out there has a better chance of survival than one of the thousands of Macs/Amigas/whatever. If you use a 9-track tape, use something like dd(1); don't assume that the future readers will know cpio/tar/ftape headers. Just dump the straight ASCII data to tape, without headers; include an ASCII map. ENSURE THAT ALL MEDIA HAS IDENTICAL DATA!!! That may help them decipher the different formats..... =========================================================================== From: mikem@travis.ssd.csd.harris.com (Mike McCole) I know for a fact that 25 year old vinyl records are playable , I own some. If they're made of virgin vynyl, they will still sound very good. =========================================================================== From: eplunix!ijs@ursa-major.spdcc.com (Ishmael J. Stefanov-Wagner) ----> vinyl record? We can still play records cut over 50 years ago; all you need is a way to spin it and a vibration pickup. Warpage through bad storage conditions is a problem, but there are groups that have managed to restore recordings on badly damaged wax cylinders that contained the sole record of a northern Canadian aboriginal language, dating from about the turn of the century. (JASA, sometime within the last 5 years?) Try doing that with your 8-track albums... Any type of magnetic media has a problem with oxide flaking - sure, I can still play some tapes made over ten years ago, but other tapes are gone after only a year of near ideal storage conditions. Helical scan or anything like that I would nix right away simply on obsolescence of the transports. I have had people come to me in a panic about not being able to find a 1/4" audio transport to play back archival recordings - and there were a number of different and incompatible track formats, even as pedestrian as 1/4" tape seems. > For computers: See above disparaging comments about magnetic media - We still have a large quantity of irreplaceable data on LINCtapes... (and they still read perfectly, by the way; cannot say that about INMAC brand 1/2" 9track, or our PDP-11 RK05s [transports all went to the dumpster] or various floppy formats...) I would avoid any type of helical scan stuff like the plague - and even though at this time we do not have a single paper-tape reader in house, I could hack together an optical reader from photodiodes to either a parallel or serial interface in under a day's work to read our 30 year old TX-0 paper tapes, which are still in a state of superb preservation (although of no known value...) Depending on the quantity of data, you may not want to use punched paper tape, and cards are a problem because they are far more bulky and must be handled individually. If I were trying to save large quantities of data for 50+ year lifetime, I would look seriously into printing with a good grade of ink onto archival paper; perhaps even a digital code like the (long gone?) Cauzin Soft-Strip (?) (R) product used, perhaps 1" wide rolled up into Corning glass reels. It is not a current or popular technique, but will not have aging problems, and can be read by a simple optical reader and debugged, if necessary, by magnifying glass. =========================================================================== From: dprrhb@Arco.COM (Reginald H. Beardsley) Guaranteed to be readable? Easy, analog phonograph disks and punch cards. Magnetic media deteriorates over time. Long life is claimed for the optical media but this is conjecture rather than proved fact. The oil industry has more computer data than any non-government entity. It is stored on millions of reels of magnetic tape. Large staffs of people constantly clean and copy the tapes to keep from losing the data which often cannot be replaced at any cost. The availability of devices to use the recordings is a different issue. For that you will have to make you own guess. =========================================================================== From: adpplz!dtb@apple.com (Tom Beach) There're two inter-related issues here. 1) What media will have survived 25 yrs in readable form and 2) For what media will there be readers in 25 yrs. >cassette tape? I'd guess that this is your best all-round answer for audio! It will last the requisite 25 yrs in readable form and given its popularity today, there will still be machines to read it in 25 yrs. >vinyl record? This is the most archival of your audio sources. It will be marvelously playable in 25 yrs if anyone still has players :-). It also suffers in that you can't record your own easily. But this WILL be playable in 25 yrs! >DAT? This suffers from both standpoints! I'm not sure DAT will survive in the audio world, except as a curiosity, for 5 years, much less 25. Also, with it's very high recording density I'd worry whether it could be read in 25 yrs even if anyone had a player for it. >VHS? This format will be around! A bit of an overkill for music and the archival nature of the medium is not understood well enough yet. I'd prefer the audio cassette myself unles you also need a video archive in which case this is probably your best bet. If you use this buy the very best high grade tape available! Do not save money on your media!! >reel-to-reel? 25 year archive fine! Again I'd worry about the availability of players although in a university setting the folks who would open your time capsule probably would have access to this technology somehow. >CD? This is the MOST archival of your options and given it's place in the audio marketplace it's a sure thing that there'll be players for it in 25 yrs. >For computers: >3.5" disk? For which computer? Probably OK for 25 yrs! I'd personally use the 770 KB format for a PC since they still outnumber the Macs by something over 10:1. >5.25" disk? Likewise! e.g. OK for 25 yrs and again I'd use the 360 KB format. At this point inf time I'd prefer the 3.5" diskette because I think it's more likely that it could be read, e.g. not damaged in teh 25 yrs. >9-track tape? tar? Nice reliable media and sufficiently archival! Potentially a problem finding readers for it 25 yrs from now. Especially in tar format. UNIX systems moving rapidly away from 9 track and toward QIC cartridges. Incidently, why didn't you include the QIC cartridges. The 6150 cartridge is currently close to a media standard in UNIXland, certainly more so than 9-track and should nearly match 9-track for archival storage. What I'd worry about here, as with all computer media, is data format! Can we presume UNIX? if so, then tar, cpio, ...??? >Punch cards? :-) Laugh if you will but these puppies will be readable! Don't you have a card reader on your home system? :-) >Optical disk? If you go optical, consider the new "multi-function" optical drives/media. This is an emerging standard and, of course, no guarentees. The BIG advantage that optical gives you for a time capsule is absolute archival longevity. This media WILL be readable! What are you planning to have in the computer readable files? Surely not executable code! Trying to guess which processors will be prevalent in 25 yrs is hopelessly more difficult than guessing which media will be readable. The same could be said for source code. If you're planning to store graphic images, the problems compound yet again. I can't think of anything you'd put on computer based media that wouldn't be more effective on paper or equivalent! =========================================================================== From: michaelb@wshb.csms.com (Michael Batchelor - WSHB Operations Eng) I don't want to be a party pooper, but the real answer is acid free paper. Print all of the documantation you want to be readable and either buy staff paper and write out your music or get one of the computer music programs to print your music on staffs. If your performance rather than the composition is the important point in the music then my GUESS, with no hard data to back it up, is that vinyl records would be most likely to be playable. (When was the last time anyone produced a 78 rpm? I have two turntables which have 78.) It might be difficult to produce your own LP's, so your next choice should probably be cassettes, but I don't have any idea how well the substrate stands up to the chemicals in the adhesive. I don't have any 25 year old cassettes. =========================================================================== From: GHGALAG%BLEKUL11.BITNET@CUNYVM.CUNY.EDU For music, I think cassette-tape or reel-to-reel is preferable. The reason: at this time, the very first magnetic recordings (Telefunken, Basf, 1930) are still perfectly readable. Take care of indicating the track format, equalization and type off recorder used. Do not use any noise-reduction (chances are small that, say, Dolby A still exists in the 21'th century...) For computers, I don't know. =========================================================================== From: gwaigh@micor.OCUnix.On.Ca (Geoffrey Waigh) >Punch cards? :-) or paper tape. If necessary include a paper tape reader in the time box. Unfortunately the paper based media are quite willing to hang around without forgetting everything for a long time, whereas most magnetic and other advanced media just fade away (EPROMS are only spec'd for 20 year data retention -- puts a crimp in using the BIOS of your computer way down the road) =========================================================================== Thanks again to everyone who responded!!! Dan //////////////////////////////////////\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ | Dan Barrett - Systems Administrator, Computer Science Department | | The Johns Hopkins University, 34th and Charles Sts., Baltimore, MD 21218 | | INTERNET: barrett@cs.jhu.edu | | | COMPUSERVE: >internet:barrett@cs.jhu.edu | UUCP: barrett@jhunix.UUCP | \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\/////////////////////////////////////