A fine example of a “rainbow disc” found in the Dean Johnson Papers

Optical media is a catch-all term used to describe those shiny, prismatic discs that we all know and love: CDs, DVDs, Blu-Ray, and to a lesser extent, MiniDiscs and LaserDiscs. Most of the optical media in the world is commercially produced, but for a long time CDs and DVDs were the average consumer’s preferred method of storing and transporting digital data. If you bothered to save your .cwk and .rm files (Appleworks and RealMedia, respectively), likely you did so on some flavor of polycarbonate pancake, poorly labeled and stored in a brightly colored “jewel case.”

As it happens, archival content acquired on optical media comprises about 20% of all digital data in NYU Special Collections, and 15% at Fales Library & Special Collections, much of that produced by the artists and organizations in the seminal Downtown Collection. Noticing that requests for content stored on optical media are increasing, but still served on a case-by-case basis, we decided that it was time to do some research on concrete strategies for preserving and making accessible the most scratch-tastic of digital storage mediums.

Trolls are an often overlooked preservation concern in optical media archives (from the Nick Zedd Papers)

But guess what? There’s not that much out there. And what is out there reveals the format to be deceptive in its technical complexity, rich in its archival implications, and limitless in preservation nuance. Which imaging tool works best for our Windows-based organization? Which one is intuitive for student workers to use? Do different filesystems image differently? And, by the way, what are the different filesystems? Can audio CDs be imaged, or should the audio tracks be extracted as separate .wav files? How can our reference staff efficiently serve the mixed contents of a rewritable and/or recordable disc in the reading room?

Annie Schweikert examines an optical disc before imaging

Luckily, NYU has one of the few moving image archiving graduate programs in the country, and in it, Annie Schweikert, who spent the Fall 2018 semester working under the supervision of myself and our Digital Archivist, Don Mennerich, researching and documenting potential optical media preservation strategies. The result is An Optical Media Preservation Strategy for New York University’s Fales Library & Special Collections an exhaustive yet highly readable report, tailored to NYU collections, but written with general audiences in mind.

The report deftly breaks down the physical and digital structures of the different optical media formats and explains the filesystem standards and extensions that characterize them. Through extensive readings, conversations with other archivists, and by reviewing NYU’s current strategies for digital preservation, Schweikert provides a solid, informed set of recommendations that can serve as a model approach for any institution beginning to tackle these issues.

Some of my favorite discoveries from the report:

• There are three ways to capture optical media: Physical,  Logical, Targeted [Page 14]
• Laserdisc is an analog format [Page 6]
• The filename character limits imposed by the ISO 9660 standard is there to ensure compatibility with different operating systems [Page 10]
• Estimates of the physical longevity of optical discs vary from 25 years to 200 years [Page 13]
• In order to accommodate NYU’s existing Windows- and FTK-based digital processing workflows, ForensicToolKit, IsoBuster Pro, and Exact Audio Copy are recommended for file, video, and audio images. [Page 17]

I’m pleased to make this document available to the community at large, both on NYU Library’s website, and the AMIA Open Source open-workflows repository. Feedback, concerns, and suggested updates are welcome either through the Github “Issues” tracker, or by emailing me, Kelly Haydon, Audiovisual Archivist, NYU Division of Libraries, Special Collections: krh292@nyu.edu.