From: whs70@dancer.cc.bellcore.com (sohl,william h)
Subject: DAT and SCMS, some info
Organization: Bellcore, Livingston, NJ
Date: Mon, 16 Nov 92 16:48:47 GMT
Keywords:  DAT, SCMS, copying


A recent poster asked for some SCMS information.  Here's a file
I've had for some time which is still pretty accurate I belive.


The following was published in a past issue
of UPDATE, the newsletter of the Home Recording Rights
Coalition, Volume 5 No. 2 and is posted with HRRC's permission.
HRRC encourages the further dissemination of this information.

  The Serial Copy Management System (SCMS)

SCMS is a system, for the first time, that will allow Digital
Audio Tape recorders (DATs) to make direct digital-to-digital
copies of compact discs.  It does not allow digital-to-digital
copies of these copies to be made.

A DAT with SCMS circuitry is programmed to read certain subcode
channels of digital source material (eg. CDs).  These subcode
channels are separate from the music channels and include: a 
"catagory code" indicating what type of digital device is being
used, a "flag" indicating whether or not copyright is asserted,
and an "L" bit indicating whether the material is from an album
(eg. original CD) or a copy of an album.  DAT recorders with SCMS
use the combination of this information to determine if
digital-to-digital copying is permitted.  If copying is allowed,
the DAT recorder inserts new codes onto the DAT tape being
recorded to indicate if future copies are permitted.

Essentially, SCMS guarantees that direct digital-to-digital
tapes of CDs, prerecorded digital tapes and future digital
radio broadcasts will be made on consumer DAT recorders.  The
only restriction introduced by SCMS is on digital copies of
digital copies, and then only if the maker of the original
digital source asserts the copy protection.

    Congressional Report Vindicates Home Taping

In an October 30, 1989 report, "Copyright & Home Copying:
Technology Challenges the Law," Congress's Office of Technology
Assessment (OTA) concludes: "although home taping may reduce
recording industry's revenue, a ban on home audio taping would be
even more harmful to consumers, and would result in an outright
loss of benefits to society, at least in the short term, in the
billions of dollars."

The OTA study was done at the request of Congress in response to
the debate about home music taping.  The key part of the report
presents the results of a national survey designed to gather
objective data about actual consumer use of home recording equipment.

Some of the OTA principal findings included:

1. "Place Shifting" is the most common reason for album taping;
home tapers usually tape their own records or CDs so that they
can play them in their cars, Walkmans, or cassette players.

2. Nearly 3 out of 4 home taping occasions do NOT involve
pre-recorded music or copyrighted material.

3. Home tapers listen to more music and PURCHASE more 
prerecorded music than nontapers.

4. Home taping stimulates album purchases.  A substantial number
of music buyers first hear the recording or artist they
eventually purchase on a homemade tape, and many buy recordings with
the expectation of taping from them.

5. The availability of dual cassette and high-speed dubbing
technology does not generate increased home taping.

6. Overwhelmingly, consumers would strongly oppose legislation
that would impose royalty taxes (on blank tape or recording
equipment) or that would prevent home taping.

(1992 update - we all know how much congress considered the
concerns and/or opinion of consumers.

In developing the survey, OTA gave industry and consumer groups of
all viewpoints, including HRRC, extensive opportunity for comment
and advice.  Earlier surveys by HRRC and the music industry had
reached some conflicting results.  HRRC strongly applauded the OTA
findings as confirming everything HRRC had been saying since 1981!
In short, home tapers act responsibly and are the music industry's
best customers.
--------------------
Anyone interested in contacting the Home Recording Rights
Coalition (HRRC) can do so as follows:

Telephone: 1-800-282-TAPE

Address: HRRC, 1145 19th Street NW, PO Box 33576, Wash DC 20033

Newsgroups: rec.audio