Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!cis.ohio-state.edu!pacific.mps.ohio-state.edu!linac!att!att!fang!tarpit!bilver!bill From: bill@bilver.uucp (Bill Vermillion) Newsgroups: comp.misc Subject: Re: SUMMARY: Media readable 25 years from now (LONG) Message-ID: <1991May10.051925.4863@bilver.uucp> Date: 10 May 91 05:19:25 GMT References: <8266@jhunix.HCF.JHU.EDU> Organization: W. J. Vermillion - Winter Park, FL Lines: 55 In article <8266@jhunix.HCF.JHU.EDU> barrett@jhunix.HCF.JHU.EDU (Dan Barrett) writes: > Thanks to everybody who mailed a response to my question: "What >media will be readable in 25 years?" Enclosed is a summary of the responses. >(Actually, many responses were kept intact because they are interesting, so >it's not much of a "summary". :-)) =========================================================================== >From: Stephen M. Smith >I would stay away from magnetic media if possible. One atomic >bomb's magnetic field could too easily erase everything... ;) This seems to be a common misconception. In the hey-dey of the cold war Scotch had done research on tapes and atomic radiation. It was published in one of their books many years ago. There is a term to describe a level of radiation that will kill 1/2 of those exposed to it. I forgot that term. But the amount of radiation 2000 times that level will affect magnetic media by increasing the print through by 3db. Increased print of 3db might be noticeable in analog music (depending on the music) but will not affect data appreciably, if at all. Care to make a guess what else you can do to damage the tape to that extent. Bring it to a level of 150F for one hour. In other words I could put a tape in my car, drive from Orlando to Miami on a summer day, and cause more damage to a tape than if it were withing 1 mile of ground zero on an atomic explosion. What you do have to worry about with tape is exposure to magnetic fields in close proximity. Anything over 1 foot away will probably do nothing unless the magnetic source is something like a device in a magnetic image resonance device. Tape dies from two common causes, heat and humidity. It likes to be in teh 50-60 degree range at about 35% to 45% humidity. Climate control is the key. Not something you want to plan for in archival mediums. =========================================================================== >From: abennett@ATHENA.MIT.EDU >Of course, the odds of *anything* of a magnetic media type still being >useable after 25 years is a bit chancey. And I have tapes from 1950 that are useable. Reel to reel. I wouldn't trust a casette for anthing important. -- Bill Vermillion - UUCP: uunet!tarpit!bilver!bill : bill@bilver.UUCP