"David W. Tamkin" <[EMAIL PROTECTED]> writes:

> Sony MD recorder manuals, in describing SCMS, have always said that signals
> from digital satellite broadcasts can be either SCMS-penultimate (you can
> record them but you can't copy the recording digitally) or mysteriously
> SCMS-antepenultimate (you can record them and copy that recording digitally
> but SCMS prevents making a third generation digitally).  We've never found
> an answer to what distinguishes the latter from the former, or how the latter
> can even happen (unless the source medium code tells an MD recorder to mark
> the recording as SCMS-penultimate).
> [...]
> So, per Yamaha, when a second generation is possible, so is a third.  The
> tuner output includes SCMS status bits, and they work like those of any other
> source, and there's no anomalous antepenultimate setting.  That completely
> disagrees with Sony, according to whom it's possible sometimes to make a 
> second generation within SCMS but never a third.

Hi David,

I remember reading somewhere that S/PDIF copy protection is a product
of the SCMS bits and the Category Code and that recording equipment
looks at both the SCMS status and whether the source is broadcast
digital audio in order to determine whether copying is allowed or not.

I've found a partially substantiating reference for this on page 7 of
the Crystal Semiconductor Application Note 22:
http://www.cirrus.com/ftp/pubs/an22.pdf "Overview of Digital Audio
Interface Data Structures, (FEB'98, AN22REV2: 117 Kb)". (Crystal
Semiconductor has a lot of interesting looking application notes by
the way: http://www.cirrus.com/products/apnotes.html).

Of note is that the L bit (original/copy) is interpreted oppositely
for these two classes:

        1) "Broadcast Reception of Digital Audio" and "Laser optical"
        2) "All other" 

So, I think the Yamaha statement is wrong, unless they implement an
unconventional copy protection for Digital Broadcasts.

Didn't I also recall reading on MD-L that people experience oddities
recording from laser optical devices?

Rick

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