I second that, I would not put much faith in old burnt media, especially the rewritable kind! Besides, a backup is only good if you test it regularly. What’s the point of having an archive if you can’t actually read it?I hate to be a worrywart, but it might be time to think about moving that data to a more durable storage medium. Optical media doesn’t last forever, and a CD-RW burned 25 years ago is already at risk of failure. Uploading to the Garden or archive.org is a good way to ensure that these kinds of things aren’t lost.
