cd longevity

A while ago - I can't remember whether it was on this list or not - I saw the question "I have some data I want to be able to retrieve in 50 years, what's the best way to store it?". Aside from "copy it to new media every four or five years or so", the only thing I ever saw proposed that sounded convincing was something machine-readable (barcodes?) on acid-free paper, kept in an inert atmosphere. (Actually, for as little as 50 years, I'm not sure the inert atmosphere is really necessary.) A megabit per page is not all that implausible; at 8x10? inches printable area per page, that's only a little over 100dpi each way. (sqrt(1048576/(8*10.5))?=?111.72756-.) Hardly suitable for routine backups of multi-gigabyte data sets, but plenty good enough for archival of many things. /~\ The ASCII der Mouse \ / Ribbon Campaign X Against HTML mouse(a)rodents.montreal.qc.ca / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B