SAN DIEGO. — San Diego -- Welcome to the Vanishing Information Age.
All that data and all those memories that you have painstakingly stored on computer disks or videotape may be at risk.
Several computer magazines have suggested recently that the half-life of computer disks is about a year and a half to two years. After that, the information on the disks may begin to disappear. ++ As Mac User magazine pointed out, ''The bottom line is that magnetic media deteriorate over time.''
Records kept on quality paper can last decades or even centuries. During the past decade, however, most of our society's daily history -- our cultural memory -- has been placed on computer disks, computer tape and videotape.
Glaring at the hundred or so computer disks on my desk, I decided to investigate. Through my computer and modem, I logged onto a local computer bulletin board and two national boards, CompuServe and America Online. I tapped out an electronic questionnaire of sorts and posted it in a number of forums. A few days later, dozens of messages were waiting.
Few people reported any significant problems with their floppy disks, so far. One fellow reported, ''I recently ran across a 5 1/2 -inch Apple II program disk that I bought in 1978. In addition to the program (a cute little data base called WHATSIT), there was some personal data that I had stored on it back then. I took it to my daughter's elementary school and tried it on an Apple there (I had sold mine in 1981). Guess what -- it ran perfectly!''
But not everyone was so pleased. Several reported that some of their old disks were beginning to go bad. Dan Gookin, a San Diego computer writer, wrote: ''Remind your readers that most serious work is kept on a hard drive. Expect a hard drive to last for a solid two or three years. Then the same thing will happen to it.''
So you don't use a computer? You think you're safe? Think again.
Videotape, remember, is also a magnetic medium. ''When I was in video class in 1981, the teacher told us to copy our videos every year if we expected to keep them,'' Mr. Gookin wrote. ''He was right. Just a few months ago, I tried to look at some of my original stuff. The quality was terrible.''
Ozzie Alfonso, a former post-production supervisor for ''Sesame Street,'' sent this message: '' 'Sesame Street consumes a tremendous amount of videotape, and unlike most productions, its tape library is constantly being used. By the late 70s we had several thousand two-inch reels, most of which we had to be duping constantly.'' The tapes were deteriorating.
''Magnetic media technology has advanced tremendously in the last decade,'' wrote Alfonso, but '' as long as you have magnetic particles glued to some other substance you'll eventually face some data loss. On 'Sesame Street,' we found the average (videotape lifetime) to be eight to nine years for tapes that were not being used.''
Think of all those home videos you are saving for your grandkids. Will they remain as pristine as the simple, old-fashioned 8mm home movies your father and mother took of you? Not likely.
Even if your home videos survive into the next century, will there be compatible machines around to play them? Tried playing a Beta tape on your VHS lately? In contrast to the new technology, the primitive 8mm projector is a relatively easy machine to re-create, if you need one.
Each generation of technology begets another wave of forgotten data. For example, in my office I have stacks of relatively obsolete IBM Displaywriter and Kaypro CM/M disks. Computer users are advised to copy their archival data onto fresh disks every two years or so. But how many computer users actually do this, or know that they should?
Maybe computer disk technology will save us all, but doubts are surfacing about the resilience of that medium, too.
What's most troubling is that the issue of long-term cultural memory rarely comes up at the companies producing these new technologies.
I called Steve Solomon, general manager of the computer media division of Fuji Photo Film USA Inc., in Elmsford, N.Y. Fuji offers a lifetime warranty for its computer disks. But this means the disk's lifetime, not yours. I asked Mr. Solomon just how long is a disk's lifetime?
''Five to eight years, possibly ten,'' he said. ''But that is based on two assumptions: that you're dealing with a higher grade disk and that the environmental conditions are stable. . . . It's a very big problem. People think they understand how to take care of the disks and they don't.''
Meanwhile, back on CompuServe, some people were outraged that anyone would even question the length of machine memory. One engineer sent this message: