In article , Serge Auckland
wrote:


The Red Book, written by Philips and Sony in 1982, contains standards
for the original compact disc (CD). It includes the physical
characteristics of the CD and CD-DA The Red Book standard defines the
format in which an audio CD must be recorded so that it will play
correctly on a CD player. Red Book is the basis for all later CD
standards and specification documents



Any so-called CD that doesn't meet Red Book standard (e.g. Copy
Protected CDs) should not be called CDs, and you can get your money
back under the Trades Descriptions Act.

IIUC The critical point is that non-Red Book discs cannot be called *Audio*
CD's or carry the standard Logo for an Audio CD. They can, however, be
called a CD. This is because the original patents have lapsed, but Philips
still own the IPR on the logo and 'trademark' name.


I have only a couple of Copy Protected "CDs", and they have changed the
cover artwork so that it doesn't say anywhere that it is a CD, doesn't
use the CD logo, and refers to itself as a "recording" not as a CD.
Consequently what I bought wasn't a CD...it may look like a CD, it may
quack like a CD but it isn't a CD.....

This is the real problem. It is all to easy to buy a non-Audio CD by
mistake - particularly if you buy by mail order or online. This makes it
almost impossible to tell beforehand.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

In article , Steve Swift
wrote:
There is no copy protection possible with audio CDs. They are nothing
but a string of digitized values and a simple index.

Some audio CD's are created with an eccentric spiral track pattern.
Domestic CD players are supposed to tolerate this; some don't. PC CD
drives are supposed to fail on these; most don't. It's a primitive copy
protection mechanism, defeated mostly by the economics.

It's also the difference between cheap writeable blank CD's and their
more expensive "Audio" versions - the audio versions have the eccentric
pattern, so are less likely to work in other PC's.

I'd be interested in knowing the source of the above as it is news to me!

My understanding is that 'Audio' and 'Data' CDR blanks differ wrt to the
information pre-written onto the blank. This is read by a consumer CDR
audio recorder and tells it not to record onto a 'Data' blank.

I've seen various 'copy protection' schemes for commercial 'audio' sic
discs, but not the one you describe, so I'd be interested to know where
the info is from.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

On Sun, 20 May 2007 21:16:52 +0100, Laurence Payne
lpayne1NOSPAM@dslDOTpipexDOTcom wrote:


I have had, shall we say, mixed experiences with USB burners.

I've used a few including the Plextor PX708 and PX740. They've been pretty
reliable unless I try to use marginal media. The only real problem I've
found is that one USB port on my laptop refuses to work with external
optical drives - although it seems fine with other USB devices.

I've had bad experiences with one particular Sony DVD writer and have
stuck with Plextors most of the time.

Cheers

James.


--
Using Opera's revolutionary e-mail client: http://www.opera.com/mail/

I've seen various 'copy protection' schemes for commercial 'audio' sic
discs, but not the one you describe, so I'd be interested to know where
the info is from.

Unfortunately I've long since forgotten where I found this, although I
seem to recall reading a reference on a website somewhere. There was
some discussion of this on an internal IBM newsgroup in 2002 when I was
already posting it as something I'd been aware of for some time. The
consensus of opinion then was that "Audio writers look for the periodic
servo error signal, and if it's not there, refuse to write the disk."

If you used "eccentric" as a search term then you're more likely to come
up with references to me personally than CD spirals :-)

--
Steve Swift
http://www.swiftys.org.uk/swifty.html
http://www.ringers.org.uk

On Tue, 22 May 2007 09:45:52 +0100, Steve Swift
wrote:

I've seen various 'copy protection' schemes for commercial 'audio' sic
discs, but not the one you describe, so I'd be interested to know where
the info is from.

Unfortunately I've long since forgotten where I found this, although I
seem to recall reading a reference on a website somewhere. There was
some discussion of this on an internal IBM newsgroup in 2002 when I was
already posting it as something I'd been aware of for some time. The
consensus of opinion then was that "Audio writers look for the periodic
servo error signal, and if it's not there, refuse to write the disk."

If you used "eccentric" as a search term then you're more likely to come
up with references to me personally than CD spirals :-)


I think you are just describing a basic feature of all CD writing which
isn't limited to just audio blanks. All CD writers look for this wobble.

Cheers

James.

I think you are just describing a basic feature of all CD writing which
isn't limited to just audio blanks. All CD writers look for this wobble.

Possibly, but we're describing a class of audio CD writers which will
refuse to write if the wobble is absent. I think the idea was that you
paid extra for the eccentric writeable CD's and that extra was then paid
as royalties to the artists. If you tried to avoid the royalties, by
using cheaper, non-audio blanks, then some writers would refuse to write.

--
Steve Swift
http://www.swiftys.org.uk/swifty.html
http://www.ringers.org.uk

In article , Steve Swift
wrote:
I think you are just describing a basic feature of all CD writing
which isn't limited to just audio blanks. All CD writers look for
this wobble.

Possibly, but we're describing a class of audio CD writers which will
refuse to write if the wobble is absent. I think the idea was that you
paid extra for the eccentric writeable CD's and that extra was then paid
as royalties to the artists. If you tried to avoid the royalties, by
using cheaper, non-audio blanks, then some writers would refuse to write.

I'm not sure, but James and yourself may be talking about different things.

Writable CDs all use a 'guide groove' whose primary purpose is to guide the
writing laser. This has a pattern of modulation (wobbles) applied which
allows to writer to determine the rotation speed required, etc, and also to
distinguish a 'Data' disc from a 'Consumer Audio' from a 'Pro Audio' one.

if you were to add 'extra' modulations the result would, I suspect, simply
confuse writers/players almost in a random way. i.e. it would be difficult
yo predict which specific writers/players would be upset, regardless of
their status as a data/consumer/pro machine. Thus I'd have expected any
such scheme to be worthless. But if the system has been tried, I'd be
curious to see details.

However that would not stop some of the dimwits in the audio biz from
having bought and tried it at some point. It is amazing how clueless and
greedy some of them seem to be. :-) I lost count years ago of all the
schemes to 'protect' LPs, let alone CDs.... None of them worked. So as
with the systems for DVD they just make themselves a PITA for honest users
and have zero effect on commercial pariates.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

On Wed, 23 May 2007 14:59:45 +0100, Steve Swift wrote:


I think you are just describing a basic feature of all CD writing which
isn't limited to just audio blanks. All CD writers look for this wobble.

Possibly, but we're describing a class of audio CD writers which will
refuse to write if the wobble is absent. I think the idea was that you

right. all zero of them.

On Wed, 23 May 2007 14:59:45 +0100, Steve Swift
wrote:

I think you are just describing a basic feature of all CD writing which
isn't limited to just audio blanks. All CD writers look for this wobble.

Possibly, but we're describing a class of audio CD writers which will
refuse to write if the wobble is absent. I think the idea was that you
paid extra for the eccentric writeable CD's and that extra was then paid
as royalties to the artists. If you tried to avoid the royalties, by
using cheaper, non-audio blanks, then some writers would refuse to write.


All CD writers will refuse to write if the wobble is absent. However,
there is also an area towards the centre of a recordable CD which contains
certain information about the CD - like the ATIP code which tells the CD
writer what sort of dye the CD uses and who made the stamper for the disc.
This information is moulded into the disc. Discs intended for consumer
audio writers contain additional information in this area to identify
themselves as consumer audio discs. This information is stored in exactly
the same way as data on a pressed CD and is the major difference between a
data CD and a consumer audio CD. It has nothing to do with the wobble in
the track on the data area of the CD.

Cheers

James.