I did a 5 year test on data retrieval (purely by accident)... I modified a scanner (radio that you listen to various police, fire public service on) to have a extended memory of 6,400 channels in 16 individual banks of 400 by removing the static ram IC chip which only gave you 400 memory channels and replacing with a larger static ram IC chip and placed a 4 position DIP switch in line so that any one of the 16 individual positions would give you access to the stored 400 channels. In theory the stored information not currently being accessed would remain there intact forever and be ready at the flip of a switch for instant retrieval. I programmed all of the known frequencies into each group of 400 for law enforcement, another one for medical, another one for fire, air traffic, business, and so on. Then later on the dip switch got broke off as it was a plug in device mounted on to top of the unit. This effectively placed me in the off off off off position and I used the scanner very little and somehow it became unplugged. The current 400 channels of memory was wiped out when the 9 volt battery that backed up the static ram went dead. But the 15 other banks should have held their memory indefinitely. But 5 years later, after getting a new DIP switch installed I tried to access the information and all of the remaining 15 banks of 400 Channels and they were nothing but unusable scrambled bits of data and of course did not work.
Moral: Don't let anyone de-materialize you into a long term storage buffer of a transporter (like on Startrek)! Depending on how long your data being stored degrades you may de-materialize as a blob of something unrecognizable, which for some would be an improvement... :) Bill ----- Original Message ----- From: [email protected] To: [email protected] ; [email protected] Sent: Tuesday, September 13, 2005 11:10 AM Subject: Re: CaveTex: OFF TOPIC: cd storage and lifespan I forwarded Vauter's email to a "friend in the know" and this is what I got back: I'd suspect that this is just a "new and improved" way to spend your hard earned dollars... Aside from the scratches, high temperatures, i.e., inside a hot car over a long period of time (and the occasional microwave trick that makes lightning) CDs are pretty indestructible... They are a "sandwich" of layered substrates one of which gets "burned" with the data... I thought the "New and Improved" advertising ploy went out with Tide? I guess P.T. Barnum was right... Here's some info on the CD life... http://www.isomedia.com/homes/isomedia/CD/cd_rom_faq/faq_41.html http://www.osta.org/technology/cdqa13.htm http://www.education.purdue.edu/edit/misc/workshops/cdrw/ http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=0002gf This should get you started... Everything else I can find in mimics this information... julia -----Original Message----- From: [email protected] To: [email protected] Sent: Mon, 12 Sep 2005 17:27:54 -0400 Subject: CaveTex: OFF TOPIC: cd storage and lifespan I know that this is off-topic, but I seem to remember a while back that someone(s) had been posting their planned experiment to see just how "permanent" cd-r's were with data backup. I ask this because I see on the back page of the latest Light Impressions catalog that there is a cd they are peddling which claims to be "the 300 Year Disc." Other claims are that it is the "best CD on the market," that its "patented dye makes stored data easier to read," and that "24k gold stops CD rot." Knowing the combined knowledge of the caving community is pretty impressive, does anyone out there have any input on this? I know that with my digital images, the only option I really have for storage is on either CD-R's or DVD's. Which is better, and is this "300 Year Disc" all it claims to be. Of course, if it only lasts 250 years, who do I go to complain to? Vauter
