Shelf life of unburned cds?
Patrick Coulthard
About 8 months ago, I purchased my second spindle of Memorex cd-r blanks.
This is the fifty pack, they are the unlabeled type; about $1 ea. They are
translucent and I think that the composition would be described as green on
silver. I bought these after having very good luck with the first package.
I burned about two-thirds of them using Toast on my PowerMac G3/233 with a
Yamaha 2x2x6 CD-RW drive. I had very good results with the discs, only a
coaster or two; the discs read easily in my computers factory cd-rom drive
and various audio cd players.
After spending the summer with better things to do, I have recently began to
start to use the discs again, but the results have been terrible. The discs
still burn fine in the Yamaha drive, but if I try to use it in the Apple
CD-ROM drive, it takes 30-60 seconds to mount. While it is mounting, I hear
the drive spinning up and down as if it is having trouble reading from the
disc. It eventually does mount, but I am not able to use the disk for very
long without getting "A disk error had occurred.." every once and a while.
After a day or so, the Apple drive ceases to read or mount the disk at all,
and instead reports: "This disc is unreadable..." Discs burned a few months
ago from this same package work flawlessly and mount in around 8 seconds. I
should also mention that the Yamaha drive that burned the cds does a better
drive of reading them, but it still doesn't match the preformance of the
discs burned earlier.
One of my friends also just told me that an audio cd I burned for him
wouldn't work in his DiscMan, but this is the first cd I've mad him, so I
don't know if the earlier ones would work or not.
Can anyone give me an explanation for what is going on. Do the discs have
some kind of shelf life, or is this just what I get for buying cheap blanks?
Thanks
Pat
Jason Dee
shelf life of 5-7 years. Long enough.
Patrick Coulthard <pmcou...@students.SPAMFREE.wisc.edu> wrote in message
news:7rkcni$ina$1...@news.doit.wisc.edu...
Dick Luhn
>What type of shelf life do unburned cds have?
Same as burned CD's I presume.
Dick Luhn
The KIWI.
It has been stated as 5 years and 100 when burnt..
The KIWI..
Robbin
Dick Luhn <Di-Loo...@Home-Perm.com> wrote in message
news:7rlks6$l6e$2...@bgtnsc02.worldnet.att.net...
> In article <7rkcni$ina$1...@news.doit.wisc.edu>, "Patrick Coulthard"
> <pmcou...@students.SPAMFREE.wisc.edu> wrote:
> >What type of shelf life do unburned cds have?
>
> Same as burned CD's I presume.
You have as usual got this 100% wrong, the unburned disk has a much shorter
shelf life than the burned one.
Robbin
Mike Yetsko
Seriously, think about it. If unburned media deteriorates much faster
than burned media, why doesn't the unburned area of burned media
deteriorate at the same rate?
Unless on burned media ALL areas are burnt, to different levels.
But I thought that burnt media modulated the beam on and off, and
there were unburned areas vs burned areas as the data pattern.
Or are there THREE levels. The three being unburnt, burnt to a 0-bit,
and burnt to a 1-bit.
What's the story?
Mike
Robbin wrote in message <7rnu9f$kns$3...@gxsn.com>...
tedma...@my-deja.com
"Mike Yetsko" <j...@user.com> wrote:
> Why?
>
> Seriously, think about it. If unburned media deteriorates much faster
> than burned media, why doesn't the unburned area of burned media
> deteriorate at the same rate?
>
> Unless on burned media ALL areas are burnt, to different levels.
>
> But I thought that burnt media modulated the beam on and off, and
> there were unburned areas vs burned areas as the data pattern.
>
> Or are there THREE levels. The three being unburnt, burnt to a 0-bit,
> and burnt to a 1-bit.
As I understand it, the shorter life span is where it gets harder to
change the state of the dye. So each spot's dye will maintain it's
state for ~100 years, but after ~5 years, the burner will not be able
to reliably change the dye from its default state.
These numbers are assuming that the discs are well cared for, e.g. kept
out of direct sunlight, etc. Also, I don't attest to the specific
numbers, 5 and 100 years, but they agree with what I've heard, at least
for some discs.
Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.
Lance Rissman
and un-burnt disks, but I do know that stablized metal and other dye types
have a shelf life of over 75 years.. I will not want a cd that long... :)
As for buring, on a cd-r the laser does only burn the 1 bits. it simply
mets the dye thus creating a surface the diffuses the laser and looks like a
hole on a regular pressed cd. The rest of the disk reflects alot of the
laser and looks like the mirrored surface of a pressed disk.
on a cd-rw, it goes a little different. I do not know exactly how this
happens, but I do know that nothing is melted or burnt, it is simply a dye
changing colour.. This reflects different amounts of light, therefore
simulating the effect the the holes and mirrored surfaces on a pressed cd.
Lance
Mike Yetsko <j...@user.com> wrote in message
news:7ro79u$je2$1...@oak.prod.itd.earthlink.net...
> Why?
>
> Seriously, think about it. If unburned media deteriorates much faster
> than burned media, why doesn't the unburned area of burned media
> deteriorate at the same rate?
>
> Unless on burned media ALL areas are burnt, to different levels.
>
> But I thought that burnt media modulated the beam on and off, and
> there were unburned areas vs burned areas as the data pattern.
>
> Or are there THREE levels. The three being unburnt, burnt to a 0-bit,
> and burnt to a 1-bit.
>
Tim Kroesen
Mike Yetsko <j...@user.com> wrote in message
news:7ro79u$je2$1...@oak.prod.itd.earthlink.net...
> Why?
Burning changes the dye affected, into a more stable chemical state.
>
> Seriously, think about it. If unburned media deteriorates much faster
> than burned media, why doesn't the unburned area of burned media
> deteriorate at the same rate?
It probably does deteriorate at the same rate. What do you consider
deterioration...? If the dye looses it's reactivity to laser light over
time this is only a problem when you need to burn it, not just read it. On
a closed disc this obviously means nothing, as you cannot burn any more to
it. Virgin media aging is another story.
>
> Unless on burned media ALL areas are burnt, to different levels.
>
> But I thought that burnt media modulated the beam on and off, and
> there were unburned areas vs burned areas as the data pattern.
>
> Or are there THREE levels. The three being unburnt, burnt to a 0-bit,
> and burnt to a 1-bit.
Burnt/opaque Unburnt/clear Two states. Lazer has Two states also - High
power to actually burn the media and Low power to just read the media (like
any player/reader)
Mike Yetsko
The first is the deterioration of the media to being able to be
burnt reliably.
The second is the deterioration of the media to being able to be
reliably read.
Mike
Tim Kroesen wrote in message ...
Tim Kroesen
> So then there are actually two different types of deterioration.
>
> The first is the deterioration of the media to being able to be
> burnt reliably.
I would say this is definitly true. The change in dye reactivity due to age
is "shelf life".
>
> The second is the deterioration of the media to being able to be
> reliably read.
On a CDR ???? Interesting notion...Could aging dye _become_ more opaque???
Can the burned pits "bleach out" over time???
This might be it's own entire thread.
Steve Trembley
Tim Kroesen <tkro...@stratos.net> wrote in message
> On a CDR ???? Interesting notion...Could aging dye _become_ more
opaque???
> Can the burned pits "bleach out" over time???
> This might be it's own entire thread.
TIM!!! I think this may be what happened to Dick Luhn!!! >: ]
Steve
bah
stored. Humidity, heat, dust, smoke, etc all play a part. Also storing
them vertically or horizontally, belive it or not. Storing vertically
in a jewel case (with the jewel case paper sleeve to block the
damaging effects of light, etc) in relatively controlled conditions is
recommended (I think the vertical position is better at avoiding disc
warpage). But with a bunch on top of each other on a spindle, there's
probably little chance of warpage.
There are so many variables, though. Part of it is probably the
quality of manufacure of the discs, part storage conditions. Who knows
for sure. Any claims of shelf life fly right out the window when your
disc is unreadable.
On Wed, 15 Sep 1999 00:02:41 +1200, The KIWI. <rog...@clear.net.nz>
wrote:
Big Daddy
Hope this helps.
BD
<tedma...@my-deja.com> wrote in message
news:7romup$pga$1...@nnrp1.deja.com...
> In article <7ro79u$je2$1...@oak.prod.itd.earthlink.net>,
> "Mike Yetsko" <j...@user.com> wrote:
> > Why?
> >
> > Seriously, think about it. If unburned media deteriorates much faster
> > than burned media, why doesn't the unburned area of burned media
> > deteriorate at the same rate?
> >
> > Unless on burned media ALL areas are burnt, to different levels.
> >
> > But I thought that burnt media modulated the beam on and off, and
> > there were unburned areas vs burned areas as the data pattern.
> >
> > Or are there THREE levels. The three being unburnt, burnt to a 0-bit,
> > and burnt to a 1-bit.
>
olrac
quickly leaving a clear plastic coaster.
I dare you to try it!
scary
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