Path: utzoo!attcan!uunet!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!usc!rutgers!netnews.upenn.edu!grip.cis.upenn.edu!paljug
From: paljug@grip.cis.upenn.edu (Eric Paljug)
Newsgroups: sci.electronics
Subject: DAT and Notch filter recording protection
Message-ID: <21875@netnews.upenn.edu>
Date: 19 Mar 90 15:47:13 GMT
Sender: news@netnews.upenn.edu
Reply-To: paljug@grip.cis.upenn.edu (Eric Paljug)
Distribution: na
Organization: University of Pennsylvania
Lines: 26

In article <2486@rodan.acs.syr.edu> amichiel@rodan.acs.syr.edu (Allen J Michielsen) writes:
>3. If you think CD's are bad, DAT has a 45DB NOTCH cut in it at 15KHZ, that is
>   about 1K wide above 3DB.  I find this offensive cut worse than anything
>   cd's could do.

In article <6296@blake.acs.washington.edu> wiml@blake.acs.washington.edu 
(William Lewis) writes:
>    I seem to remember this being some sort of bizarre copy protection
>scheme -- the DAT will refuse to record unless there are frequencies
>in this notch, and commercial stuff will be distributed with those
>frequencies cut out. It sounds too stupid to be true, but I've heard this
>several places (now including the net). Real flat response, uh huh ...

Didn't this go before a congressional committee a year or so ago and the 
committee found that the notch filter altered the product so much that it was 
unacceptable?  In fact, I thought this ruling (combined with SONY buying
the record company who was making the case for the prevention of recording
commercial products) basically ended the record industry's attempt at 
preventing the recording of commercial stuff.  

I didn't follow this stuff too closely but I think the above is accurate.
Corrections are welcome!

Eric Paljug	

paljug@grip.cis.upenn.edu