[Ti] OT Durability of DVDs

[b]

Sam Hotchkiss paused, thought it over, and spoke thusly:

>On 9/10/03 11:08 AM, "John Griffin" <jwegriffin at mac.com> wrote:
>
>>  Sam Hotchkiss typed this message on 9/10/03 11:30 AM:
>>
>>>  It has to do with the dye in the DVD deteriorating, but a burned 
>>>disc should
>>>  last at least 5 if not 10+ years
>>
>>  Gimme a break! I have floppy disks that are 15+ years and they still read
>>  just fine!
>
>Congrats?  Floppy disks don't use dye-- they are a magnetic media.

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Sam,

I'm not a mind-reader, so I can't vouch for John G's point, but, when 
I hear about 5 -10 yr life expectancy on DVDs or CDs, I have to 
wonder also. I, too, have some ancient floppies. (Like Photoshop 
(plus example files) on a 400K floppy, for example), and hardly any 
of hundreds of them have deteriorated noticeably in a lot of years. 
So, as of yet, the cheaply constructed CDs that most of us use leave 
me under-whelmed.

DVDs and home-version CD burners, and blanks, haven't been around 
long enough to for any 'long-term reliability' theory to be anything 
more than speculation.

Steve W. (I think?) mentioned burning at 1X, which would be similar 
(albeit on different formats) to the fact that good analog magnetic 
recording tape preserves better than mass-produced (factory) 
cassettes, and fidelity is better, also, when one-to-one ratios are 
used. <--'Real' time, in other words.

The cool thing about digital is that, unlike records and tapes 
(gaps), instead of missing a beat, you can go from 'page' 93 to 
'page' 4,117, and back somewhere else. And in the early days of 
digital recording 'clipping' (over-driven saturation), instead of 
producing a distortion (as on tape), produced 'blank areas'...i.e. 
total gaps.

In the old days it was easy to record a vinyl 'master' wherein the 
bass, if left unattended as far as clipping was concerned, would 
result in needles jumping right out of the groove. Compressors came 
in handy at that point. With digital media we thought, "Oh boy, no 
more need for compression." And, to an extent, that was true. But 
then along came the really artificial 'response' of digital media to 
clipping, (not to mention the fact that most speakers weren't 
designed to produce whomping 30 cycle frequencies), and it was back 
to the limiters and compressors, again.

For data, of course, all of this that I mention is beside the point. 
The big issue, to my way of thinking is: What happens when, through 
advancement, or consolidation (whatever) directories on the CDs and 
DVDs are no longer in the lingua franca of playback systems? No 
matter how well preserved the actual data, once you get the "This is 
not a recognizable format" dialog, it's over. Data recovery can get 
pricey, and is justified in extreme, and limited, cases, but an 
entire collection of years of data/images/video, etc???   I wouldn't 
want to have to pay for it.

I wouldn't bank on anything lasting all that long. Although I did get 
a kick out of the recording they sent up (What was it Voyager 1, or 
2?). I think the guys at JPL / NASA used some kind of super thick 10 
or 12" disk to carry quotations, mathematics formulae, Chuck Berry 
music, etc. That was sent up quite a while ago, and last I heard it 
was intact and headed clean out of our Solar System.

One starts to wonder if the stone-cutters and hieroglyphics guys were 
on to something.

~flipper