| From: "Josh Glover" <jmglov at wmalumni.com>
| Date: Fri, 6 Jul 2007 22:12:21 +0900
| On 06/07/07, Michael Watterson <watty at eircom.net> wrote:
| > dd is not going to help except on the less smart anti-copy protection.
| Not sure I agree with this; dd makes a bitwise copy. [ ... ]
| the CD produced should be an exact replica of the orginal;
| copy protection intact.
the CD must be a data CD. since it is a bit-wise copy,
the format of the data (i.e., ISO-9660, tar(1) archive,
proprietary, whatever) is not relevant (provided, of
course, you copy the entire CD).
however, dd(1) cannot copy audio CDs: data CDs have
an I-forget-how-many number of ECC bytes per sector,
but audio CDs do not. what are ECC bytes on a data
CD are use as additional payload bytes on an audio CD.
the occasional bit-error is considered Ok for audio,
but would be a disaster for data.
| Some CDs employ bad sectors and shite, but dd should not care about those.
eh?! if the bad sector or whatever causes a read(2)
error, `dd' will most certainly care (in its default
mode of operation).
the ILUG archives contain several previous threads
on both the differences between data and audio CDs;
and on `dd'(-like) programs and I/O error handling.
but, _guessing_, the contents of both the ECC bytes
(and payload) for the "bad" sectors matters to such
copy-protection schemes, naïve `dd' is probably not
the tool to use. what the "correct" tool is, and
it's legality, I do not know.
▶ ▶ I AM CURRENTLY LOOKING FOR A JOB! ◀ ◀ | Brian Foster
Experienced (>25 yrs) software engineer: | Montpellier, FRANCE
• Unix, Linux, embedded, design-for-test; | Stop E$$o (ExxonMobile)!
• Software/hardware co-design, debugging; | http:/www.stopesso.com
• Kernels, drivers, filesystems, &tc; Résumé (CV) & contact details:
• IDL, automated testing, process, &tc. http://www.blf.utvinternet.ie
Maintained by the ILUG website team. The aim of Linux.ie is to
support and help commercial and private users of Linux in Ireland. You can
display ILUG news in your own webpages, read backend
information to find out how. Networking services kindly provided by HEAnet, server kindly donated by
Dell. Linux is a trademark of Linus Torvalds,
used with permission. No penguins were harmed in the production or maintenance
of this highly praised website. Looking for the
Indian Linux Users' Group? Try here. If you've read all this and aren't a lawyer: you should be!