On Thu, 1 Aug 2019 23:09:32 -0400 (EDT) "D. Hugh Redelmeier via talk" <talk@gtalug.org> wrote: > > - petroglyphs: long long time > > - clay tablets: millennia > > - paper (pre-wood-pulp): five hundred years > > - paper made from wood pulp: 75 years > > - punch cards and paper tape: 100 years > > - 9-track mag tape: 10 years > > - digital cassette tape 4 years (formats changed too quickly) > > - floppy disks: 5 years? Depends on the format (consider 3.0" > floppies) > > - USB flash drives: I've had them die after a year, but that's not > expected. > > - hard drives: death by standards evolution. Try finding an ST506 > controller. Or MFM, ESDI, SCSI, FireWire. Support for even PATA > is fading. > > - Laser Disc, Magneto-optical disks, CD-ROM, DVD (multiple standards), > BluRay: each has standards that get obsolete. The actual data may > deteriorate too. I do have some DVD that claim to have a lifetime > of over 100 years.
Hugh, I copy my HDD backup to Blu-Rays periodically. Occasionally, I have had to recover stuff from them, and it has always worked. Typically, this was months after the fact. I archive my digital photos to DVD. I store these in a dark, cool place, and again, they are doing fine. My good camera has two SD cards, one of which I have designed as a backup. I have my DVD archive, my Blu-Ray backups, and I archive the SDs when they are full. I think my odds are pretty good. It is getting harder to find DVD and Blu-Ray discs in stores. The next time I order DVDs, it will be online, and I will order archival quality. -- Howard Gibson hgib...@eol.ca jhowardgib...@gmail.com http://home.eol.ca/~hgibson --- Post to this mailing list talk@gtalug.org Unsubscribe from this mailing list https://gtalug.org/mailman/listinfo/talk
