5 ms·

CD: Certificate of Deposit.

by Loic 3y ago

mnd999 3y ago
Thanks, for some reason I though credit derivative.
- can16358p 3y ago
  I thought Compact Disc, yours is still more relevant.
  - Tade0 3y ago
    Same here. Most of mine didn't survive 10 years before becoming unreadable. A Blu-ray disc that's guaranteed to last 100 years would really be something. Of course by that time there would be problems with finding a device that could read such a storage medium, but I assume a custom one could be made easily with the technology of the 22nd century.
    - aidenn0 3y ago
      Huh, almost all of my CDs work great. Are you talking about pressed CDs or CD-Rs? The latter definitely have a much shorter shelf-life than the former.
      - Tade0 3y ago
        Mostly CD-Rs, but I have a few pressed CDs which don't read at all any more, despite looking fine on the outside.
    - fragmede 3y ago
      Buy a 100 of them and keep them with the discs. Also keep adding adapters so you can connect your then present-day laptop with USB-40 all the way down to the USB-3 connector that we're using today.
      - Tade0 3y ago
        > Buy a 100 of them and keep them with the discs. Of course! My only concern is that plastic parts often start getting brittle after 35 years or so and might simply not survive. In the meantime I found an alternative a solution: there exist consumer-grade 3D printers with 50um precision - hooking up a camera with a microscope in place of the nozzle should be enough to produce pictures of e.g. 100um x 100um tiles and stitching them together to get an image of the whole disc.
    - gambiting 3y ago
      >>A Blu-ray disc that's guaranteed to last 100 years would really be something. All BDXLs should last that long, easy. In fact Blu-Ray Mdiscs were rated for 1000 years - but they didn't even bother certifying BDXLs as MDiscs since they use the exact same technology. The BDXL 128GB quad layer discs are meant to be the most durable of all of them.
      - photonerd 3y ago
        > In fact Blu-Ray Mdiscs were rated for 1000 years Rated by their marketing team, not by reality. Independent testing showed marked different results. Better than regular discs? Yes. 1000 years? No. Not even close (10-50 years seemed the range, depending on conditions)
        dabluecaboose 3y ago
        I realize this isn't really the thread for this, but what is the most longevity-rated storage medium, tape?
        gambiting 3y ago
        Surely, it's paper. Properly stored it remains readable for thousands of years.
        photonerd 3y ago
        Standard medium? Paper stored well. Custom special? Probably some form of the metal engraving encased in glass. GlassMasterDisc by Syylex was an attempt to do that for DVDs but I don’t think they’re made anymore. Those actually were a LOT better than MDisc in practical tests
        humanistbot 3y ago
        You can't just focus on longevity of the material medium, because then you'll be carving into clay tablets, which we have actual proof that it can last for millennia. Or maybe that is perfect if you only have a few very important kilobytes to store for millennia, don't need to retrieve data through a digital network, and can trust that there will be people who will know how to decode it. Longevity is a function of both the material stability of the medium and usability (of storage, of retrieval, of space, of scale, of complexity, of cost). If nobody can decode those bits, it doesn't matter if they are still in the medium. The most optimal storage system is not a single technology, it is a well-funded and well-managed institution. You need people to regularly check integrity of redundant archives and replace individual media when they fail. You also need people to migrate the entire archive to new storage technology when the current generation is growing obsolete. The institution has to regularly buy and maintain drives and computers that can read it, which is often overlooked. Another major issue is longevity and documentation of the data formats and encodings. The bits can still be on the medium, and your drive can still read them, but are you're out of luck if you don't know how it was encoded. "Tape" is not a single medium, it is a class that includes some formats that are now incredibly difficult to decode. Look at this recent thread about what is needed to read from an old IBM tape format, it's an expensive mess: https://groups.google.com/g/bit.listserv.ibm-main/c/AOlRa0qxY60?pli=1 https://groups.google.com/g/bit.listserv.ibm-main/c/AOlRa0qx...
- benj111 3y ago
  I've only ever seen the initials being used for Contract for Difference in a financial context.
rob74 3y ago
I love the way they try to explain it in the article: > CDs are a federally insured way for investors to receive a fixed interest on their deposit for a fixed period, in return for not being able to withdraw the money early without a penalty. ...still not spelling out what the abbreviation actually means - ok, it's in the paragraph above the one I quoted, but hidden away in a subordinate clause that's easy to overlook if you just scan the text. I was in the "Compact Disc" camp too BTW...

CD: Certificate of Deposit.

by Loic 3y ago

CD: Certificate of Deposit.

mnd999 3y ago

Thanks, for some reason I though credit derivative.

can16358p 3y ago
I thought Compact Disc, yours is still more relevant.
- Tade0 3y ago
  Same here. Most of mine didn't survive 10 years before becoming unreadable. A Blu-ray disc that's guaranteed to last 100 years would really be something. Of course by that time there would be problems with finding a device that could read such a storage medium, but I assume a custom one could be made easily with the technology of the 22nd century.
  - aidenn0 3y ago
    Huh, almost all of my CDs work great. Are you talking about pressed CDs or CD-Rs? The latter definitely have a much shorter shelf-life than the former.
    - Tade0 3y ago
      Mostly CD-Rs, but I have a few pressed CDs which don't read at all any more, despite looking fine on the outside.
  - fragmede 3y ago
    Buy a 100 of them and keep them with the discs. Also keep adding adapters so you can connect your then present-day laptop with USB-40 all the way down to the USB-3 connector that we're using today.
    - Tade0 3y ago
      > Buy a 100 of them and keep them with the discs. Of course! My only concern is that plastic parts often start getting brittle after 35 years or so and might simply not survive. In the meantime I found an alternative a solution: there exist consumer-grade 3D printers with 50um precision - hooking up a camera with a microscope in place of the nozzle should be enough to produce pictures of e.g. 100um x 100um tiles and stitching them together to get an image of the whole disc.
  - gambiting 3y ago
    >>A Blu-ray disc that's guaranteed to last 100 years would really be something. All BDXLs should last that long, easy. In fact Blu-Ray Mdiscs were rated for 1000 years - but they didn't even bother certifying BDXLs as MDiscs since they use the exact same technology. The BDXL 128GB quad layer discs are meant to be the most durable of all of them.
    - photonerd 3y ago
      > In fact Blu-Ray Mdiscs were rated for 1000 years Rated by their marketing team, not by reality. Independent testing showed marked different results. Better than regular discs? Yes. 1000 years? No. Not even close (10-50 years seemed the range, depending on conditions)
      - dabluecaboose 3y ago
        I realize this isn't really the thread for this, but what is the most longevity-rated storage medium, tape?
        gambiting 3y ago
        Surely, it's paper. Properly stored it remains readable for thousands of years.
        photonerd 3y ago
        Standard medium? Paper stored well. Custom special? Probably some form of the metal engraving encased in glass. GlassMasterDisc by Syylex was an attempt to do that for DVDs but I don’t think they’re made anymore. Those actually were a LOT better than MDisc in practical tests
        humanistbot 3y ago
        You can't just focus on longevity of the material medium, because then you'll be carving into clay tablets, which we have actual proof that it can last for millennia. Or maybe that is perfect if you only have a few very important kilobytes to store for millennia, don't need to retrieve data through a digital network, and can trust that there will be people who will know how to decode it. Longevity is a function of both the material stability of the medium and usability (of storage, of retrieval, of space, of scale, of complexity, of cost). If nobody can decode those bits, it doesn't matter if they are still in the medium. The most optimal storage system is not a single technology, it is a well-funded and well-managed institution. You need people to regularly check integrity of redundant archives and replace individual media when they fail. You also need people to migrate the entire archive to new storage technology when the current generation is growing obsolete. The institution has to regularly buy and maintain drives and computers that can read it, which is often overlooked. Another major issue is longevity and documentation of the data formats and encodings. The bits can still be on the medium, and your drive can still read them, but are you're out of luck if you don't know how it was encoded. "Tape" is not a single medium, it is a class that includes some formats that are now incredibly difficult to decode. Look at this recent thread about what is needed to read from an old IBM tape format, it's an expensive mess: https://groups.google.com/g/bit.listserv.ibm-main/c/AOlRa0qxY60?pli=1 https://groups.google.com/g/bit.listserv.ibm-main/c/AOlRa0qx...
benj111 3y ago
I've only ever seen the initials being used for Contract for Difference in a financial context.

rob74 3y ago

I love the way they try to explain it in the article: > CDs are a federally insured way for investors to receive a fixed interest on their deposit for a fixed period, in return for not being able to withdraw the money early without a penalty. ...still not spelling out what the abbreviation actually means - ok, it's in the paragraph above the one I quoted, but hidden away in a subordinate clause that's easy to overlook if you just scan the text. I was in the "Compact Disc" camp too BTW...