Frequently Asked Questions About CD-R and CD-RW Discs

Please contact Media Sciences if your questions are not answered on these pages.

Sometimes CD-R writing aborts, and the recorded disc is not readable? What is wrong with my discs?

Even though media is often blamed, not all problems are media related. Reliable duplication can be achieved only when media, recorder, recording software, operating system, system hardware, operator, and the environment are all of high quality. Many of these are addressed in our CD RECORDING seminar.

Recording drives that work only with a few media brands usually are defective, and result in unpredictable failures, even with preferred media. Firmware updates or replacement of the drive may be necessary.

Recording software may cause failures by writing in the wrong mode, with incorrect methods, or using improper formats. XA modes, multisession methods, or invalid postgaps are common problems. Software caching may be buggy, or legal SCSI commands may not always be issued.

Common operating system problems are the presence of power management or other TSRs, resource conflicts, device problems, and buggy drivers. Critical drivers usually have DLL (application extension, dynamic link library), MPD (miniport driver), and VXD (virtual device driver) extensions. One common problem is the ASPI layer (Advanced SCSI Programmer's Interface) that contains many shared files. These control communication between recording software and the drive. Installation of flawed software can adversely affect the ASPI layer. See FAQ65 for details.

Critical hardware issues include RAM, the SCSI bus, and hard drive. Although insufficient RAM can cause problems, excess capacity can as well, especially if VCache is active. Careful design of the SCSI bus and proper terminations are critical. Use a separate SCSI or fast IDE PIO Mode 4 hard drive for the image. This drive must not contain TEMP files, swapfiles, or caches.

The operator can adversely affect duplication quality, either through the incorrect selection of software options or by improper handling of the media.

Finally, a clean environment is essential. Dust, debris, or fingerprints on the media will partially mask the laser beam, resulting in permanent defects recorded in the dye.

Duplication quality requirements are complex, but are well defined, and can be managed by regularly testing blank media, recorded discs, and the drives. Functionality is not a valid quality indicator. Only comprehensive testing of drive and media can predict successful interchange.