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
Drag and drop (UDF packet
writing)
Copying CDs
Creation of audio CDs
Creation of data CDs
CD Type
CD-RW
MultiRead CD-ROM drive with UDF reader
CD-R
Most CD-ROM drives
(Closed)
CD-RW
MultiRead CD-ROM drive
CD-R
Any CD-ROM drive
CD-RW
MultiRead CD-ROM drive
CD-R
Any CD-ROM drive, home/car CD player
CD-RW
MultiRead CD-ROM drive
CD-R
Any CD-ROM drive
Target drives