10 key queries on CD-recordable tech

Electronic News, April 7, 1997

The following has been extracted from an OSTA publication entitled "CD-Recordable Questions and Answers" and is intended to help the novice understand the benefits of this fast-growing new technology.

1. Are CD-R's reliable and read-compatible?

OSTA: Yes and yes. The media is as reliable as are your safeguards to insure proper handling and storage of the media. Media manufacturers estimate the shelf life of unrecorded CD-R media to be between 5 and 10 years. For recorded media, the CD-R media manufacturers have performed extensive media longevity studies using industry-defined tests and mathematical modeling techniques, with results claiming longevity from 70 years to over 200 years. With proper handling and storage, your CD-Rs will outlive you.

2. What is the difference between 63-minute and 74-minute media?

OSTA: Very early CD recorders specified the use of 63-minute media, but current generation recorders can handle either. You may be able to save a small amount of money by using 63-minute media, but most CD-R media suppliers offer 74-minute discs at the same price as 63-minute discs. Today's CD-R media, whether 63-minute or 74-minute capacity, are equally reliable.

3. How can I clean my CD-R media?

OSTA: Use a lens tissue, and wipe the disc in a radial direction. This is recommended because, should you happen to scratch the media, the reader is less likely to be affected by a radial scratch than a circumferential one.

4. What are the advantages of recording CDs versus CD replication (stamping)?

OSTA: For short runs of CD-Rs, there can be both an economic advantage and a turnaround advantage. Stamped or pressed CDs typically require a three-day or longer turnaround to avoid a rush cost penalty, and these services are better suited for runs over 250. CD-R is used when the total quantity required is less than 200 and there is a need to produce the CD in hours, not days. Additionally, CD-R is preferable if customization of content or labeling is desired.

5. Can you tell if a disc has been written just by looking at it?

OSTA: For a partially written disc, the answer is yes. For a full disc, you can compare it to an unwritten disc to see that the reflectivity has changed and that the disc has been written.

6. Will standard CD-R media work in Kodak PhotoCD equipment?

OSTA: PhotoCD is a system for storing and retrieving photographic quality images using CD. The equipment is designed to work with, and the licensing agreement with Eastman Kodak Co. requires the use of, PhotoCD branded CD-R media, which is available from Eastman Kodak and other photographic companies, such as Fuji. Most commercially available CD-R media will work in the Kodak PCD200-series writers. Note that Kodak PCD600, which records at 6X speed, produces optimum results when used with Kodak Infoguard media and may not work with non-PhotoCD media.

7. Why can't writing a CD be as easy as writing to a hard disk?

OSTA: You are right in not wanting to worry about formats and standards. They should be, and are increasingly becoming, transparent to the user. Still, you do need to specify which type of CD you wish to create because the recorder manufacturers and software vendors allow you to choose between audio formats, data formats (ROM) and photo or video formats, the standards for which have been agreed to by the appropriate industry groups. By using those standards, you guarantee interoperability for yourself, because later you may wish to read the data on a different CD reader. The really good news here is that with the emergence of CD-Recordable with multisession packet writing, writing to a CD-R disc has become as easy as writing to a hard disk.

8. Does the location of files on a disc have any effect on playback performance?

OSTA: Yes, but to a very minor degree. The fastest retrieval is for those data placed on the inside tracks (near the start of the CD). If your CD is written in "disc at once" mode, and you therefore have some control over critical indexing information, that information should be copied to the CD before other data files. For a multimedia type disc, the location of files can be extremely important so that files that are likely to be accessed together are physically close to one another on the disc.

9. Can I record directly from DAT to CD-R?

OSTA: The DAT formats for audio and data are different on tape than on CD-R. You need first to convert the format using a disk-based PC system, next make the appropriate PQ edits, and then write the information to CD-R using a premastering software package. If your DAT is pre-edited with PQ information, the Alea System can copy the audio DAT to CD-R.

10. Why aren't there inexpensive audio CD recorders that are as easy to operate as a cassette deck?

OSTA: There have been a few attempts to make the CD recording process as easy to operate as a cassette deck, and others will surely follow. As for "inexpensive," CD recorder prices have fallen dramatically over the past two years, and they are expected to continue dropping. When first introduced in 1989, a CD recorder cost over $60,000. The current generation of CD recorders cost less than $1,000.