[rollei_list] Archiving

  • From: "Peter K." <peterk727@xxxxxxxxx>
  • To: rollei_list@xxxxxxxxxxxxx
  • Date: Fri, 15 Jun 2007 19:35:58 -0700

Jeff,

Early CD disks were problematic. Much was written on the problems they
had, like any new technology there are always drawbacks until things
get better made and much improved. The early CDs had problem with the
top lacquer coatings as they would peel off. Today's DVDs have a
plastic layer on each side and are far better sealed. They truly are
much better at longevity as are the dye materials they are using these
days. Then you have to consider proper storage.

But I do agree with you on multiple copies. My most valuable docs and
images I keep on DVD-R or +R and another copy on a large capacity USB
Hard Drive. In 10 years I am sure there will be some other media we
will be using and DVDs will be like a floppy, something few people use
these days.

Peter K

On 6/15/07, Jeff Kelley <thocker@xxxxxxxxxxx> wrote:




Anything of real value should be copied to several media and stored in
separate locations.

I worked on CD ROM hardware and software during the early years of the
technology at a big company that starts with "S" and end with "y."  Blank
CDs were $30.  Writers were $10,000 or more.

I've had gold discs burned at 1x, stored under perfect conditions become
unreadable in less than five years.  DO NOT trust this stuff, any of it, for
archival storage of irreplaceable data!

Jeff


> Date: Fri, 15 Jun 2007 17:52:50 -0700
> From: peterk727@xxxxxxxxx
> To: rollei_list@xxxxxxxxxxxxx
> Subject: [rollei_list] Re: Rangefinder article
>
> Yes Richard, documents that are not easily found or rare should be
> kept on something more archival like a DVD+R. They will outlast CDs.
> Also burn them at a slower rate to ensure best burn and longer
> readability. A slower burn ensure more accurate shaped pits/markings
> resulting in a potentially longer archival/readability.
>
> Peter K
>
> On 6/15/07, Richard Knoppow <dickburk@xxxxxxxxxxxxx> wrote:
> >
> > ----- Original Message -----
> > From: "Peter K." <peterk727@xxxxxxxxx>
> > To: <rollei_list@xxxxxxxxxxxxx>
> > Sent: Friday, June 15, 2007 2:41 PM
> > Subject: [rollei_list] Re: Rangefinder article
> >
> >
> > Hi Richard,
> >
> > Thank you. The RW disks actually require the laser to
> > erase/blank them
> > before they are written. They usually use a material
> > different than
> > dye so that they can control the phase change. The material
> > is
> > basically one where a higher power laser and subsequent
> > cooling
> > changes the state of the material used. To erase the
> > pits/disk in a
> > disk, or blank it, there is a process known as annealing
> > accomplished
> > by heating the material to a lower temperature.
> >
> > Problem with RW is that although the claim is that they will
> > last a
> > long time, they do not meet the higher standards of write
> > once
> > CD/DVDs. While you might use them for storing images for a
> > few months,
> > DVD-R/+Rs are less expensive and offer more stable long-term
> > storage,
> > it only makes sense to stick with those if you are
> > archiving.
> >
> > UC Berkeley has a good article (from 2001) posted that
> > offers a better
> > detailed explanation of the RW process at:
> >
http://www.mse.berkeley.edu/classes/matsci102/F01reports/dvdrw.pdf
> >
> > Peter K
> >
> > Thanks Peter, I will check out the reference. I use discs
> > mainly for storing documents. I expect reasonable life,
> > several years minimum, but not archival life. It sounds like
> > I should copy the more important stuff to write-once discs.
> > FWIW, there appears to be an astonishing amount of
> > technical publications of historican importance on the web.
> > For instance, I recently downloaded two RCA internal
> > publications with all their proprietary knowledge about
> > designing and making vacuum tubes. This is simply not
> > available elsewhere.
> >
> > ---
> > Richard Knoppow
> > Los Angeles, CA, USA
> > dickburk@xxxxxxxxxxxxx
> >
> > ---
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> >
>
>
> --
> Peter K
> Ó¿Õ¬
> ---
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