Recent Finds & Thoughts

From: Allison J Parent <allisonp_at_world.std.com>
Date: Fri Nov 27 22:15:47 1998

< copying them onto a correctly aligned machine would be the first thing t
< do to remove such hassles in the future :-). I still don't see how
< incorrect azimuth can be used as a copy protection system.

It can't. People were likely adjusting them to try and get reliability
in loading and assumeing that was the copy protection. Audio tape is
as difficult to copy protect as a vinyl recording, you can't effectively.
Commercial casettes tend to have lower levels as the dup machines try not
to saturate the tape as that would introduce distortion to music, also
most were design for stereo (narower head). Most cassette recorders use
a mono head (wider) so they pack up less and also when the record they
write a wider path meaning they recover more on play back. Stereo tapes
tend to play at lower levels and have poorer response on mono decks
because of the head with differences.

The only way to copy protect and audio tape is not try or make it so it
only works on a given machine.

Audio cassettes and computers stopped being company around or before '85
and I was there and never saw "copy" protection. I did see a lot of off
speed, poorly recorded, tape with horrid print through, dropouts from
poor tape (some you could see through!) and other recording errors that
would never be noticed if it were music. Actually the best protections
was each vendor had a different tape standard for format, data rate and
encoding method. None of that was deliberate, most was simply
implementation artifacts. The best being L1 trs80 used a slower rate
than LIIs on the same exact hardware.


Allison
Received on Fri Nov 27 1998 - 22:15:47 GMT