Misty De Meo Walks Through Making the Best Possible Archive Copies of Your Precious CD-ROMs
Forget your ISOs: if you're serious about preserving your optical discs then this guide has what you need to know.
Archivist, librarian, coder, and vintage computing fan Misty De Meo has penned a guide to preserving data from CD-ROM optical discs — using readily-available enthusiast-centric tools.
"I’ve seen a lot of professional archivists who use flux disc image archiving techniques for their collections — a technique in which a specialized floppy controller captures the raw signal coming from the floppy drive so that it can be preserved and decoded in software. I haven't, however, seen many archivists using enthusiast-developed low-level reading techniques for CD-ROM," De Meo explains. "I've personally been making use of these techniques and I find them very helpful; I know that many other archivists and institutions could make great use of them."
De Meo's tour of enthusiast-led optical media archiving tools is an effort to make them more accessible to professional archivists looking to preserve media for future generations — though it's also applicable to anyone looking for best-practice approaches. It focuses on preserving optical media to the Redump.org standard — a disc preservation community that hosts a database of metadata and has a firm opinion on how discs should be archived.
"Redump's standards makes use of raw reading functions that are available on a certain set of CD drives," De Meo explains. "These raw reading functions completely disable the processing the firmware would normally apply to data tracks: the data is read in its original scrambled form, with error correction disabled, so that data is returned in as close to its original form as possible. The software then performs descrambling and error correction after it's read."
While this does require a compatible CD-ROM drive, they're readily available and easily affordable. De Meo talks of two tools known to create archives to Redump.org's exacting standards, though only one is currently recommended: Hennadiy Brych's command-line redumper. "Its feature set is relatively restricted compared to DiscImageCreator," De Meo admits, "but its opinionated defaults ensure it just does the right thing without extra configuration."
The full guide, including links for downloading the software, a list of compatible CD-ROM drives, and tools for converting the resulting images to a more common ISO file format for use with emulators, is available on De Meo's website.