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on 4:48 pm
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Great meeting on Thursday with the Telstra Rep in attendance
He was quite honest about how Telstra are doing things
It may not have been helpful in some cases but at least you know where you stand
Following is some information from Fred Langa http://www.langa.com
I highly recommend his newsletter for beginners and experts alike
We have spoken of the lifespan of CD's and DVD's at meetings in the past
I thought you might be interested in Fred's opinion
Good Afternoon Fred--- I know you have written a number of times about the lifespan of CDs. Recently a friend read an article from http://www.pressofac.com/life/story/5972740p-5966674c.html which had the following excerpt:
Those blank CD-Rs are coated with a layer of dye, which is burned with new information when put in a computer's CD burner. A laser in the computer melts the dye, and that is how information is stored. That dye degrades at different rates depending on the quality of the dye, Dorkin said. For example, blank CDs that are called gold CDs contain a higher quality dye that produces a longer shelf life for photos or music.
I am interested in two items at present: 1) Are the lifespans of CDs the same as DVDs, or perhaps there is a different manufacturing process?, and 2) Since your last writing, has there been any technological changes to the manufacture of CDs and DVDs that make one or several brands notably superior by their implementation of such a contemplated process? Best Regards, Bruce McCormick
CDs first appeared on the market in 1982, so the oldest CDs in existence are just 24 years old. DVDs arrived in 1996; the oldest DVDs are only 10 years old. And, because both technologies were slow to take off, the vast majority of discs in existence are relative newborns.
Plus, the technologies have changed over time; some newer dyes, for example, have only been around for a relatively few years.
All of which simply means that no one can say, with certainty, how long these discs will usefully hold data over the long haul; it's all guesswork and extrapolation based on accelerated aging tests. There just hasn't been enough time to know--- really know, for certain--- how long they'll last.
Best guess for ordinary office or home storage of CDs and DVDs (e.g not a darkened, climate-controlled, refrigerated vault): If you keep you discs out of direct sun or bright fluorescent light, don't use labels or any kind of adhesives on them; write on them only with water-based or safe-solvent felt-tipped pens; and protect them from abrasion; you probably can count on at least 10 years life. Maybe it's a lot more, but again, know one really knows yet.
Ten years isn't a long time in historical terms, but it's a very long time technologically: 10 years from now, who knows what the current best archival storage medium will be?
So, your best bet is to treat your CDs and DVDs carefully, test them from time to time, and plan on moving their contents to newer, better media when it comes along. (Even if your new DVD lasts 100 years, who's going to have an ancient PC and an ancient operating system to play it then? It'd be like someone handing you an Edison wax recording cylinder today: Even if you knew what it was, all you could do with it is give it to a museum!)
Lots more, including info on the different dyes used in CDRs:
http://www.informationweek.com/showArticle.jhtml?articleID=15800263
Contact Information
This email is brought to you on behalf of the Mulligrubs - Milton Ulladulla Internet & Computers Users Group
http://mulligrubs.shoalhaven.info/
The Mulligrubs meet on the last Thursday of each month at the Ulladulla CTC - Top of the Town Complex, Ulladulla NSW 2539
Send comments, suggestions, or questions about this newsletter to mulligroup@miltonulladulla.com
You can subscribe or unsubscribe from this discussion group at any time.
Simply send a request to mulligroup@miltonulladulla.com
All names and addresses will be kept confidential and will never be sold or used for any other purpose than forwarding of this newsletter
He was quite honest about how Telstra are doing things
It may not have been helpful in some cases but at least you know where you stand
Following is some information from Fred Langa http://www.langa.com
I highly recommend his newsletter for beginners and experts alike
We have spoken of the lifespan of CD's and DVD's at meetings in the past
I thought you might be interested in Fred's opinion
Good Afternoon Fred--- I know you have written a number of times about the lifespan of CDs. Recently a friend read an article from http://www.pressofac.com/life/story/5972740p-5966674c.html which had the following excerpt:
Those blank CD-Rs are coated with a layer of dye, which is burned with new information when put in a computer's CD burner. A laser in the computer melts the dye, and that is how information is stored. That dye degrades at different rates depending on the quality of the dye, Dorkin said. For example, blank CDs that are called gold CDs contain a higher quality dye that produces a longer shelf life for photos or music.
I am interested in two items at present: 1) Are the lifespans of CDs the same as DVDs, or perhaps there is a different manufacturing process?, and 2) Since your last writing, has there been any technological changes to the manufacture of CDs and DVDs that make one or several brands notably superior by their implementation of such a contemplated process? Best Regards, Bruce McCormick
CDs first appeared on the market in 1982, so the oldest CDs in existence are just 24 years old. DVDs arrived in 1996; the oldest DVDs are only 10 years old. And, because both technologies were slow to take off, the vast majority of discs in existence are relative newborns.
Plus, the technologies have changed over time; some newer dyes, for example, have only been around for a relatively few years.
All of which simply means that no one can say, with certainty, how long these discs will usefully hold data over the long haul; it's all guesswork and extrapolation based on accelerated aging tests. There just hasn't been enough time to know--- really know, for certain--- how long they'll last.
Best guess for ordinary office or home storage of CDs and DVDs (e.g not a darkened, climate-controlled, refrigerated vault): If you keep you discs out of direct sun or bright fluorescent light, don't use labels or any kind of adhesives on them; write on them only with water-based or safe-solvent felt-tipped pens; and protect them from abrasion; you probably can count on at least 10 years life. Maybe it's a lot more, but again, know one really knows yet.
Ten years isn't a long time in historical terms, but it's a very long time technologically: 10 years from now, who knows what the current best archival storage medium will be?
So, your best bet is to treat your CDs and DVDs carefully, test them from time to time, and plan on moving their contents to newer, better media when it comes along. (Even if your new DVD lasts 100 years, who's going to have an ancient PC and an ancient operating system to play it then? It'd be like someone handing you an Edison wax recording cylinder today: Even if you knew what it was, all you could do with it is give it to a museum!)
Lots more, including info on the different dyes used in CDRs:
http://www.informationweek.com/showArticle.jhtml?articleID=15800263
Contact Information
This email is brought to you on behalf of the Mulligrubs - Milton Ulladulla Internet & Computers Users Group
http://mulligrubs.shoalhaven.info/
The Mulligrubs meet on the last Thursday of each month at the Ulladulla CTC - Top of the Town Complex, Ulladulla NSW 2539
Send comments, suggestions, or questions about this newsletter to mulligroup@miltonulladulla.com
You can subscribe or unsubscribe from this discussion group at any time.
Simply send a request to mulligroup@miltonulladulla.com
All names and addresses will be kept confidential and will never be sold or used for any other purpose than forwarding of this newsletter
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