Preparing a CD for Classroom Use
Faculty who have chosen to burn their course materials onto CDs from their home computers may experience difficulty with classroom computers reading their CDs. There seems to be an issue particularly with CD-RW media. The classroom units have CD-R drives which have known compatibility problems with some CD-RW software.
The best solution is to use CD-R disks for classroom materials instead of the CD-RW disks.
A faculty member may receive help with a CD that is not being read in a classroom computer by calling the Help Desk. When reporting this issue the following information would be very helpful for the Help Desk staff in resolving the problem:
- What software/version did you use to burn the CD-RW?
- What error message appeared when trying to read the CD-RW?
- When you burned the CD, did you select the option to leave the session Open or Closed?
Most current CD rewritable software offer the following choices when copying files
to a CD:
- Open Session – Still able to write to CD, but cannot be read from another computer
- Close Session – Close current open session so data can be read, but CD still open
- Open CD – Still able to write to CD, but not to a closed session
- Close CD – Close CD, cannot write to this CD anymore
What's the difference between a CD-R and CD-RW Disk?
CD-Recordable (CD-R) disks are WORM (Write Once, Read Multiple) media that work just like standard CDs. The advantage of CD-R over other types of optical media is that you can use the disks with any standard CD player. The disadvantage is that you can't reuse a disk.
A related technology called CD-Rewritable (CD-RW) allows you to erase disks and reuse them, but the CD-RW media doesn't work in all players. Regular CD players cannot read CD-RW disks because the amount of laser light reflected from the disc is much smaller than regular CD-Rs and the current player's eye cannot read the data. The CD-RW disks are not writable by standard CD-R drives, nor readable by most older CD readers. Most newer CD-ROM drives do support CD-RW media, but not all of them will read CD-RW disks at full speed. However CD-Rewritable drives are able to write to either CD-R or CD-RW disks.
All CD-RW drives ship with special software to allow users to copy and delete files on the CD. Some software may handle CD-RW in a slightly different way, because you can do things like erase individual files, but the recorder technology is nearly identical.
A few older audio CD players and many new ones can handle CD-RW disks, but many can't. If you want to create audio CDs on CD-RW media, make sure that your player can handle them first.