wet-behind-the-ears whippersnapper seeking advice on building a nationwide network

Barry Shein bzs at world.std.com
Tue Sep 20 18:22:50 UTC 2011

On September 20, 2011 at 02:00 henry at AegisInfoSys.com (Henry Yen) wrote:
 > A few (dozen) years ago, I was treated to a interesting demonstration where
 > a coworker poured an oily fluid containing tiny metallic flakes on a patch
 > of tape.  The "bits" on the tape could be clearly seen by the naked eye,
 > and could be decoded (ever so slowly!) using a magnifying glass.

Magnetic Tape Developer, you can still buy it (see link below). I
remember playing with the stuff back in the days when punch cards were
still your friend. I suppose it wouldn't be that hard to make your own
but I think the liquid was a fast-drying light solvent or CFC, not
oily, so it'd dry, you could read it, and then shake/wipe/dust it off.

It was supposedly handy for recovering physically mangled tapes, it
wasn't that rare for a tape to just get jammed in a drive and get so
crumpled it wouldn't go thru a drive any more and you didn't have a
backup tho usually at that point you dug out the original punch cards
and re-created the data set or whatever, had the data re-keyed (that
means punched back onto punchcards, or even key-to-tape, from its
pencil+paper source) because using tape developer would be too
expensive in terms of people-hours. Or you just applied to law school
and hoped for the best.





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