I have somewhere a GAO report that lists the problems, lifetimes, and quantities of data that the US government has on different magnetic media. IIRC the big problem with magentic media is that it is never stored in the correct environmental conditions that provide optimum lifetimes. They included pictures of piles of 9-track tapes of LANDSAT data, some of the stacks were used to block open the door to the tape library. Humidity and heat are big problems for tape. Here are several references about data storage and media Preserving Digital Objects: Recurrent Needs and Challenges. Michael Lesk. Bellcore. Abstract. We do not know today what Mozart sounded like on the... URL: www.lesk.com/mlesk/auspres/aus.html . Effects of Humidity on Life Expectancy of Media. Long-Term Preservation of Dig <http://www.safesupplies.com/article1.html> Long-Term Preservation of Digital Materials. Dr. John W.C. Van Bogart National Media Laboratory. Presented at the National Preservation Office (NPO)... URL: www.safesupplies.com/article1.html http://www.cclabs.missouri.edu/~ccgreg/tapes.html Magnetic Tape and Digital Media Life Expectancies Preservation of New Technology <http://palimpsest.stanford.edu/byauth/lesk/lesk2.html> ...as digital media, DAT cartridges, 9-track tape in... ...example, half-inch 9-track magnetic tape densities have... palimpsest.stanford.edu/byauth/lesk/lesk2.html - Cached </search?q=cache:palimpsest.stanford.edu/byauth/lesk/lesk2.html> - 58k - GoogleScout </search?num=10&q=related:palimpsest.stanford.edu/byauth/lesk/lesk2.html> I think that the September 1995 issue of Scientific American had an article about preserving digital data. Mike