# Reading CD-ROMs

Knoppix has built-in support for reading Compact Disc Digital Data discs. It is best to have two CD drives – one for the Knoppix CD, and one for the data CD that you want to read. If not, see “If you have only one CD drive” in the “Advanced startup options” section. To read a data CD:
* Insert the data CD into an empty CD-ROM drive.
* Click the icon on the Desktop on that represents the drive. The “CDROM” icon represents the first CD drive, and “CDROM1” represents the second drive. In Windows, the first drive is given a lower drive letter (eg “D:”). The second drive is given a higher drive letter (eg “E:”).
* A green triangle will appear on the CD drive icon to indicate that the drive is in use.
* Wait while the Konqueror file manager starts up.
* The files on the CD will be displayed.

## Ejecting the CD

* Close all windows and files opened from the CD.
* Press the Eject button on the front of the drive.
* The CD tray will be ejected.

## Quick help

Question: When trying to access a CD for the first time, it says “The file or directory file:/mnt/cdrom does not exist”. What does this mean? Usually this means the drive is still preparing itself, or the Knoppix auto-mounter has not finished working yet. Wait a few moments, then try again. If it still doesn't work, click the Home icon in the Panel, then type file:/mnt/auto/cdrom or file:/mnt/auto/cdrom1. If it still doesn't work, click the Knoppix icon in the Panel, click Root Shell, then enter this command:
Question: Why is the CD stuck in the drive? Knoppix uses the locking mechanism of the drive to prevent you from taking out a CD that is still in use. Close all windows and documents opened from the CD, then try again.
Question: When I right-click on the CD drive's icon and then click “Eject”, it says “Eject failed!” What does that mean? It means the drive doesn't like the Knoppix “eject” program. Just press the eject button on the front of the drive instead.

# CD writing

Knoppix has built-in support for CD writing. To create your own CDs using Knoppix, it is best to have two CD drives. You need one drive for the Knoppix CD, and a Compact Disc Re-Writeable drive for the blank media. Normally, the Knoppix CD occupies the first drive, and it cannot be removed while Knoppix is running.
However, if you have a suitable hard disk, it is possible to start Knoppix from a single CD-ROM drive and then use it for other CDs. See the later section, “Advanced startup options”.
The following CD-RW drives are compatible with Knoppix:
* All SCSI CD-RW drives.
* Nearly all IDE CD-RW drives produced after 1999.
* Some IDE CD-RW drives produced before 1999.
* Most external (USB) CD-RW drives.
Knoppix uses SCSI commands to create CDs. When working with IDE CD-RW drives, Knoppix uses SCSI emulation. This means that Knoppix works with IDE CD-RW drives while actually using the SCSI language to talk to the drive. For this reason, SCSI CD-RW drives are ideal, while most IDE CD-RW drives should work. To copy files onto a data CD:
* Select the files or folders to be written onto CD.
* Right-click on the selection.
* Click “Create CD with K3b”.
* Wait for a moment while the K3b program starts.
* The K3b window will be displayed. In the “Current Projects” pane, you will see the folder that you chose. To add additional files and folders, drag and drop them into the Project pane.
* The disk usage is in shown in the green bar at the bottom of the Projects pane. It shows the amount of space that will be used on the writeable CD. This example shows 90.3 MB will be used, out of a possible 650 MB.
* Click the “Burn” button (fourth from the left in the toolbar). The disk writing window will be appear. The make and model of your CD-RW drive will be shown.
* Select the writing speed to be used from the “Speed” box. The correct writing speed to choose depends upon the speed of your CD-RW drive and the media. For example, if you have an 8x CD-RW drive and 4-10x compatible media, choose 8x.
* Click the “Filesystem” tab.
* Click “Generate Joliet extensions” to put a tick in the box. This step is needed to make the CD fully readable in Windows. If you are only going to use the CD in another Linux or UNIX computer, you do not need this.
* Click “Write”.
* The CD will be created. When the writing process has finished, the CD will be ejected.
* Click “Close” to return to K3b.

## Quick help

Question: Why does it eject the CD and do nothing? Or, why do I get an error while CD writing? You may be trying to use incompatible media. For example, if you try to write onto CD-RW media labelled “4-10x compatible” at 32x then the drive will just eject the blank CD.
Question: When I put the written CD in a computer running Windows, some of the file names come out in capitals and some spaces or dots are turned into underscores. Why? You need step 10, “Generate Joliet extensions”. The original specification for data CDs allows each file name only 8 characters plus a 3 character extension. For example: “hello.txt” fits, but “long file name of your dreams.txt” does not. “Joliet” is the Microsoft way of putting long file names on a data CD.
Question: The setup works fine, but when it gets ready to burn, there are no devices to be selected. How come? You need to run K3B as root. Go to a terminal (the image of a monitor with a shell on it), then type 'su', hit return, then type 'k3b' and hit return. This runs K3B as root and fixes some issues.
Question: how to read the data from cd and DVD