Differences between version 4 and predecessor to the previous major change of CompactDisc.
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| Newer page: | version 4 | Last edited on Friday, March 11, 2005 9:28:31 am | by JohnMcPherson | Revert |
| Older page: | version 3 | Last edited on Saturday, November 6, 2004 1:09:45 pm | by AristotlePagaltzis | Revert |
@@ -1,10 +1,34 @@
-''InNeedOfRefactor: needs some cleanup of content across [CDROM], [CDWritingNotes] and [ISO]. Also need an IsoImage page to untangle the mess on the other pages.''
-
Round shiny things made of aluminium and plastic.
Often used for copying LinuxDistribution~s onto and distributing at InstallFest~s.
-For audio, the logo "Compact Disc Digital Audio" is actually owned by Philips and licensed for use by manufacturers who meet the RedBook
standard for digital audio. Many forms of CopyControl degrade the audio quality or alter the data structures on the plastic wafer in an attempt to prevent customers using the data. By thus degrading their product, the manufacturers may no longer meet the RedBook
standard, meaning they cannot ''legally'' be called CompactDisc~s.
+Standard discs hold 650[MB] or there abouts, although 700MB discs are also common.
+
+!!! Audio Discs
+
For audio, the logo "Compact Disc Digital Audio" is actually owned by Philips and licensed for use by manufacturers who meet the "Red Book"
standard for digital audio. Many forms of CopyControl degrade the audio quality or alter the data structures on the plastic wafer in an attempt to prevent customers using the data. By thus degrading their product, the manufacturers may no longer meet the "Red Book"
standard, meaning they cannot ''legally'' be called CompactDisc~s.
Since consumers might notice that plastic wafers which do not work in their equipment are missing the "CD" logo and so stop bying such CopyControl~led wafers, there is an incentive for manufacturers to mislabel their discs.
So be on the lookout for things that are ''not'' CompactDisc~s which are labelled illegally while shopping.
+
+
+
+!!! Data Discs
+
+The normal filesystem used on a data disc is [ISO]9660. Hence the common use of "[ISO]" to refer to disc images and of the extension <tt>.iso</tt> for their filename.
+
+Images can be created using mkisofs(8) and inspected using isoinfo(8) or isodump(8). You do not need root permissions or any special devices to use these commands (although you do need normal read/write file permissions). Alternatively, you can mount an ISO image like a regular device using the [Kernel]'s loopback support (but note that this requires SuperUser privileges)::
+
+ <verbatim>
+ # mount /path/to/image.iso /place/to/mount -o loop
+ </verbatim>
+
+There are two competing standards to allow longer filenames and a few other things [ISO]9660 does not provide. The earlier one, originating from the [Unix] environment, is called Rock Ridge. The other one, made up my MicrosoftCorporation, is called Joliet. (Note that some characters that are valid on [Unix] FileSystems are not allowed on Joliet discs.)
+
+
+!!! Compact Discs and your computer
+For reading audio discs or writing CDs, you need access to the [CDROM] drive raw device. For a data disc, this raw device should be [mountable|mount(8)] onto the filesystem.
+
+Under a [Linux] OperatingSystem, these raw devices are called <tt>/dev/hd''x''</tt> for [IDE] drives and <tt>/dev/scd''n''</tt> for [SCSI] drives. Under [FreeBSD] 5 and later, they're called <tt>/dev/acd''n''</tt> for [IDE] drives and ''??? (AddToMe)'' for [SCSI] drives.
+
+See also:
+* [CDWritingNotes]
