CHAPTER 13

756 Chapter 13 Optical Storage
Figure 13.13 MultiRead and MultiRead2 logos.
How to Reliably Record CDs
With typical burn times for full CD-Rs ranging from under 4 minutes (20x) to as long as 80 minutes
(1x), it is frustrating when a buffer underrun or some other problem forces you to rewrite your CD-
RW disc, or worse yet, turn your CD-R media to a coaster—an unusable disc that must be discarded.
Five major factors influence your ability to create a working CD-R: interface type, drive buffer size, the
location and condition of the data you want to record to CD-R, the recording speed, and whether the
computer is performing other tasks while trying to create the CD-R.
To improve the odds of getting reliable CD-R/RW creation, look for drives with
Tip
■ A large data buffer (2MB or larger), or better yet some form of buffer underrun protection. The data
buffer in the drive holds information read from the original data source, so that if a pause in
data reading occurs, there’s less of a possibility of a buffer underrun until the on-drive buffer
runs empty. A larger buffer minimizes the chance of “running out of data.” Newer drives with
buffer underrun protection virtually eliminate this problem, no matter what size buffer is in the
drive.
■ Support for UDMA operating modes. As you’ve already seen, UDMA modes transfer data more
quickly and with less CPU intervention than earlier versions of ATA. To use this feature, you’ll
also need a motherboard with a busmastering UDMA interface with the appropriate drivers
installed.
Also, if you have problems with reliable CD-R creation at the drive’s maximum speed, try using a lower speed (4x instead
of 8x, for example). Your mastering job will take twice as long, but it’s better to create a working CD-R slowly than ruin a
blank quickly.
An alternative approach is to use packet-writing software to create your CD-R. All late-model CD-
R/CD-RW drives support packet writing, which allows drag-and-drop copying of individual files to the
CD-R/RW rather than transferring all the files at once as with normal mastering software. This “a little
at a time” approach means that less data must be handled in each write and can make the difference
between success and failure. If your drive supports this feature, it probably includes packet-writing
software in the package. Note that although packet-written CDs can be read with Windows 9x, Me,
NT, and 2000, they can’t be read with Windows 3.1 and MS-DOS because these operating systems
don’t have drivers available that support packet-written CDs.
If your CD-R/RW drive is SCSI-based, be sure you have the correct type of SCSI interface card and
cables. Although many drive vendors take the uncertainty out of this issue by supplying an appropriate
card and cables, others don’t.