test-drb July 2001

test-drb@ccmp.vtda.org

301 participants
824 discussions

by CLASSICCMP＠trailing-edge.com

Sellam Ismail said: > On Tue, 24 Jul 2001, Carlini, Antonio wrote: > > > Personally, I have only had one read-failure in several hundred burns. > > That's not counting a few coasters along the way - this was a partial > > read-failure some six months to a year later when I came to use the > > CD. > > Wait ten or twenty years, and then make your assessment. That's what Tim > is concerned with. And a test I use - a carbon-arc-lamp nicknamed "buttercup". (If there are any ex-Dabney-House readers here, they'll get the reference.) I can only run it intermittently, but all cyanine-based CD-R's become unreadable after a few hours of 10% exposure to it. (I think a few hours is somewhere around a decade of solar UV exposure.) The CompUSA-super-duper cheapies (CMC Magnetics by the ATIP code) become unreadable after just a few minutes. I think these use the cyanine dye without any stabilizers at all. I've melted pthalocyanine-based CD-R's (Kodak Ultima and Mitsui Gold) by putting them too close to the arc, but never damaged the data otherwise :-) Of course, two seconds in the microwave on "high" completely destroys them *all*! Tim.

22 years, 11 months

Kodak Gold CD-R's going bye-bye?

by Antonio.Carlini＠riverstonenet.com

> Jerome Fine wrote: > >long I can expect any files to still be readable? Also, how long is it likely >that the magneto optical drive will last. I suspect that the drives are likely This is (I hope) the key. 5.25" floppies don't appear on mainstream PCs anymore. 8" floppies are still available (but there were IIRC more varieties than there were with 5.25"). 3.5" floppies are too small to last too much longer (although so far many of the attempted replacements - like the LS120 - are backwards compatible). I'll try not to mention 3" floppies (plus all the others I've never come across). I expect that CD drives will go the same way over the next five to ten years. Finding one twenty years from now will be somewht tricky. >"What sort of strategy is recommended to always be sure that old files (stored >on old media which can only be read with old drives) be rescued/copied to newer >media before that is no longer possible?" Firstly you have to get them into a portable digital form. For many things that just means copying them off the old media and archiving onto current media (i.e. CD or MO or whatever you happen to like). For some stuff (boot disks, copy-protected disks etc.) you have to archive in some kind of image format that preserves the original characteristics. (ISTRC reading a paper about some US uni doing exactly this and inventing an archival format ... but I've lost the reference). Once you have made the initial digital backup your task is much simpler. It would take me a lot of time to archive all of my floppy disks (especially if I try to verify that I can accurately recreate the original media from the archive copy). But once I've done that, I can probably fit all of them onto a handful of CDs (I'm guessing that I can get 500 floppies at least onto a CD and I doubt that I have even a few thousand ... so call it five CDs to be safe). That might take months, perhaps years of copying and verifying (cataloguing might be nice too !). Once it is done I could run off a second set in a few hours. And a third, and a fourth ... We'll skip DVD ... not enough of a leap forward and too hamstrung by Hollywood fo rthe prices to drop quickly enough for my liking. Five to ten years from now, when recordable C3D is commonly available, I can repeat the process for all my CDs (which by then may number a few thousand). At 125GB per C3D I should be able to get at least 175 CDs per C3D, so that's maybe 10 C3Ds to archive absolutely every piece of digital data I will have then. Again, a second backup for safety will (hopefully) be quite quick. At each stage, I can verify digital backup copies against each other fairly easily (I'm assuming that data rates will go up as capacity goes up ... otherwise I see a bottleneck looming!) It all depends on how careful I am making the initial archival copy. >Obviously, every user would like to skip as many in-between steps as possible. >But since safety is perhaps more important, where should the compromise be made? Anything I care about now, I burn twice for myself. I always check the CD-Rs individually against the original source. >"What standard needs to be used to determine what files may be of interest in >50 years, 500 years or even 5000 years?" That's easy. You keep everything. Even the most expensive CD-R media is incredibly cheap compared to the prices three years ago. Obviously if you have terabytes of data this may not be so easy. But if you have terabytes of data it may still be easier to archive everything (which is likely to be a fairly mechanical process) rather than spend time sifting through deciding what to keep. >It is fine to be discussing the technical details of how to save files, but if everything >needs to be saved, that creates many difficulties. For example, if some software >is being developed, it's rare that non-distribution files ever see the light of day, much >less that they get saved beyond the next distribution. In most cases, only the final >source and executable files get saved and it is probably rare for OBJ and MAP files >to be saved. What is the best way to develop criteria that can determine which >files will be of interest to someone looking to understand how "programs" were >written 5000 years ago? Better still would be to attempt to determine the questions >that will be asked 5000 years from now. Looking back, I would suggest that the >first footstep on the Moon back in 1969 may not have been as important as the >technology that was needed to make it all possible. I'm actually at the beginning of archiving some stuff at work right now. Copying the source directories (and the version control stuff) to CD in a PC-readable format is fairly straightforward. Same for the final listings, obj, exe etc. (although much of that could be recreated). The bit I think will be difficult for a historian to understand in a hundred years is how to build the product once you have re-created the environment. Archiving people's knowledge is not currently on the agenda ... it takes too much time. Antonio

22 years, 11 months

need help with an old ST-251 MFM drive...

by Robert_Feldman＠jdedwards.com

You can get an MCT 4-Drive Floppy Controller (MCT-FDC-HD4 $29.99) from JDR Microdevices (http://www.jdr.com/interact/item.asp?itemno=MCT-FDC-HD4). Only problem is that it must be the primary floppy controller, so you will need to pull the existing floppy controller card. -----Original Message----- From: Ethan Dicks [mailto:ethan_dicks@yahoo.com] Sent: Wednesday, July 25, 2001 3:10 PM To: classiccmp(a)classiccmp.org Subject: Re: need help with an old ST-251 MFM drive... <snip> 2) Locate a high-density 8-bit floppy controller and use 1.44Mb disks. I have one - it has its own BIOS to handle the differences. They would be difficult to locate now, so unless you already have one, it's probably not a good solution. -ethan

22 years, 11 months

Big newspaper interview for me! (lets see whats gonna happen now...)

by claudew＠videotron.ca

Hi all I am not a very "public" person but I could not turn this one down... An offer for an interview with a big Montreal newspaper... Photos and hour long interview about vintage computer collecting...show off a bit of the collection etc... Lets see if this will bring in some rare finds/offers or just emails from people with 286s and XTs that will be asking $50 for them... By the way, I still have the tape of CBCs Undercurrents and their report on vintage computer collecting and hope to find a card to capture this and transfer it to .avi or similar and let you all have a chance at seeing this report...If anyone has a ATI capture card or similar I am open to offers.....I have an old Spigot card here for NUbus MAcs but doubt that will produce anything pleasant... Claude http://www.members.tripod.com/computer_collector or http://computer_collector.tripod.com

22 years, 11 months

FS: Toshiba T1000XE

by bola＠piraeii.demon.co.uk

Hey: I don't think I'm going to persuade this to run X, so ... It includes what I assume is the original carrying case, UK mains power supply and a battery. Everything seems to be working. Any profit will be going to the Oxfam whence it came, if that helps to loosen any wallets. -[z].

22 years, 11 months

Source for anti-static bags?

by jss＠ou.edu

So... where do I get anti-static bags that for hex-height Unibus and other big boards? -- Jeffrey S. Sharp jss(a)ou.edu

22 years, 11 months

Warning OT.. Humor Thermodynamic Question........

by rigdonj＠intellistar.net

> >THERMODYNAMICS OF HELL --A little "levity" for today. > > The following is an actual exam question given on a University of >Washington chemistry mid term. The answer by one student was so "profound" >that the professor shared it with colleagues, via the Internet, which is, >of course, why we now have the pleasure of enjoying it as well. > > Bonus Question: Is Hell exothermic (gives off heat) or endothermic >(absorbs heat)? > > Most of the students wrote proofs of their beliefs using Boyle's Law, >(gas cools off when it expands and heats up when it is compressed) or some >variant. One student, however, wrote the following "First, we need to >know how the mass of Hell is changing in time. So we need to know the rate >that souls are moving into Hell and the rate they are leaving. I think >that we can safely assume that once a soul gets to Hell, it will not leave. >Therefore; no souls are leaving. As for how many souls are entering Hell, >lets look at the different religions that exist in the world today. > >Some of these religions state that if you are not a member of their >religion, you will go to Hell. Since there are more than one of these >religions and since people do not belong to more than one religion, we can >project that most souls go to Hell. With birth and death rates as they >are, we can expect the number of souls in Hell to increase exponentially. > >Now, we look at the rate of change of the volume in Hell because Boyle's >Law states that in order for the temperature and pressure in Hell to stay >the same, the volume of Hell has to expand proportionately as souls are >added. > >This gives two possibilities > 1. If Hell is expanding at a slower rate than the rate at which souls >enter Hell, then the temperature and pressure in Hell will increase until >all Hell breaks loose. > > 2. If Hell is expanding at a rate faster than the increase of souls >in Hell, then the temperature and pressure will drop until Hell freezes over. > > So which is it? > > If we accept the postulate given to me by Teresa during my Freshman >year, "...that it will be a cold day in Hell before I sleep with you.", >and take into account the fact that I still have not succeeded in having >that event take place, then, #2 cannot be true, and thus I am sure that >Hell is exothermic and will not freeze." > >**The student received the only "A" given.**

22 years, 11 months

VCFE Shopping List

by RCini＠congressfinancial.com

I posted my shopping list on http://www.vintage.org I have to be careful...whatever I get I have to sneak into the house :-) Two things I left off of my list were a DecWriter III (too big to sneak in) and a 22U rack cabinet with a glass front door (also too big to sneak in). "No, honey, really. I didn't buy anything more than this t-shirt." Rich ========================== Richard A. Cini, Jr. Congress Financial Corporation 1133 Avenue of the Americas 30th Floor New York, NY 10036 (212) 545-4402 (212) 840-6259 (facsimile)

22 years, 11 months

hope to find paper tape reader at VCF East

by uban＠ubanproductions.com

One of the things that I would like to find at VCF East is a paper tape reader. Preferably something small that I can either connect to a serial port, or interface to a parallel port. I will also be looking for interesting peripherals for my PDP 11/45... --tom

22 years, 11 months

More for the Hayes Chronograph

by ethan_dicks＠yahoo.com

OK... now I'm starting to dig... found this: http://wuarchive.wustl.edu/systems/cpm/genasm/spttim10.aqm Which is described by the readme as... NOTE: This list was created on Sun Oct 26 12:14:58 EST 1997 Some files may have been added or deleted since that date. See file pub/cpm/filedocs/aaaread.me for additional information. NOTE: Type B is Binary; Type A is ASCII Directory pub/cpm/genasm/ Filename Type Length Date Description ============================================== . . . spttim10.aqm B 5120 850209 Time support package for DC Hayes Chronograph Anyone have a handy Z80 disassembler with a CP/M symbol table? I'm just curious what's in there. -ethan ===== Visit "The Seventh Continent" http://penguincentral.com/penguincentral.html __________________________________________________ Do You Yahoo!? Make international calls for as low as $.04/minute with Yahoo! Messenger http://phonecard.yahoo.com/

22 years, 11 months

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test-drb July 2001