Friday 1 February 2013

CDs versus floppies

The digital rescue mission continues...

Here are a few words from James who is in the middle of his internship on this project and has been moving his focus away from floppy disks and on to CDs within the office:

Floppy disks - more robust than we expected!
"I am finding it very enjoyable rifling through collections of CDs and floppy disks
to try and discover what they contain, what is recoverable, what has duplicates saved elsewhere and what is important. Something that has been a big surprise to me, and I have found really interesting, was to discover that the floppy disks appear to have a greater lifespan than the CDs that superseded them. Out of the 97 floppy disks I’ve been through (most of these were from the 1990s) only one is completely corrupt. This is in contrast to the 62 CDs I have been working with (mostly from the 2000s) of which there were 4 entirely corrupt
disks. It just seems odd that the older technology outlasts the more modern."

So in our sample, the floppies have a 1% disk corruption rate whereas for the CDs it is somewhere around 6.5%. Is this typical? It will be interesting to see if this pattern continues as we move on to digital material in the strongrooms.

There is an interesting analogy from my colleagues who work on the conservation of analogue material within the archive. Apparently, the same is true of paper. Old paper is generally of better quality thus in a better state of physical preservation than more modern paper. I love it when my work on digital material finds parallels in the traditional archival experiences.

It just goes to show, they don't make things like they used to!

Jenny Mitcham, Digital Archivist

3 comments:

  1. We're seeing a similar outcome with audiovisual formats. We're wrapping up a two-year digitization project (250 oral history interviews) and have been finding that Mini-DV and VHS are better than DVD for video, while cassette is lasting better than CD for audio. I've just started going through the QR summaries and adding all the metadata for these interviews but that's the trend I'm noticing thus far.

    Jenny Mitcham, Digital Archivist

    ReplyDelete
  2. Thanks for sharing your experiences Tim. Interesting to see that your findings follow the same pattern. We intend to move on to look at the AV material in the archive at some point and we seem to have a wide range of media formats in need of rescue. Perhaps we need to prioritise the most recent of these!

    Jenny Mitcham, Digital Archivist

    ReplyDelete
  3. At the School of Information, University of Texas at Austin, we have been taking bitstreams off old media since 2005, though we haven't done much with newer media. We have certainly found that 3.5" media do very well, while 5.25" media are also astoundingly stable, their main problem being dirt, which means very frequent head-cleaning and danger to the old drives that are becoming increasingly scarce. It seems that since most 5.25" media were superseded and needed contents were quickly migrated after the maturation of Windows (3.1) using dual-media machines (which were common in the late 80s and 90s), people actually used the original media for a fairly short period of time, after which the disks sat in shoeboxes or equivalent and the microscopic dust slowly sifted in.
    Pat Galloway

    Jenny Mitcham, Digital Archivist

    ReplyDelete

The sustainability of a digital preservation blog...

So this is a topic pretty close to home for me. Oh the irony of spending much of the last couple of months fretting about the future prese...