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4 multiread – Philips DVDRW22899 User Manual

Page 5

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1.4 MultiRead

You will always be able to read CD-RW discs in the CD-RW drive you created them in, but they often
cannot be read in older CD-ROM drives or CD players that do not comply with the '

MultiRead

'

specification.

The recorded tracks on a CD-RW disc are read in the same way as regular CD tracks: by detecting
transitions between low and high reflectance, and measuring the length of the periods between the
transitions. The only difference is that the reflectance is about one-third of that of the original CD
specification. That is why many older CD-ROM drives or CD players cannot read CD-RW discs.

Using modern techniques this presents no problem. The '

MultiRead

' specification drawn up by Philips

and Hewlett Packard and approved by the Optical Storage Technology Association (

OSTA

) provides

for the necessary adjustments, thus solving any compatibility issues for all modern CD-ROM or DVD
drives and CD players.

The following table is a short summary of which CD drive types can read discs created with certain
application/media combinations:

Function

CD Type

Target drives

CD-RW

MultiRead CD-ROM drive with UDF reader

Drag and drop (UDF packet
writing)

CD-R
(Closed)

Most CD-ROM drives

CD-RW

MultiRead CD-ROM drive

Copying CDs

CD-R

Any CD-ROM drive

CD-RW

MultiRead CD-ROM drive

Creation of audio CDs

CD-R

Any CD-ROM drive, home/car CD player

CD-RW

MultiRead CD-ROM drive

Creation of data CDs

CD-R

Any CD-ROM drive