Writing
1.) How
many times can the CD-RW disc be rewritten?
2.) Why
is it possible only to write at 2x (for a 2x CD-RW disc) when the
writer can support 4x rewriting?
3.) Why
does the CD-RW disc capacity decrease to about 530 MB from 650 MB
after the disc is formatted with Direct CD 2.5?
4.) What
does 'Orange Book' mean?
1.)
How
many times can the CD-RW disc be rewritten?
About 1000 times.
2.)
Why
is it possible only to write at 2x (for a 2x CD-RW disc) when the
writer can support 4x rewriting?
The CD-RW disc was initially developed and
sold for 2x rewriting. If one tries to write at 4x onto the 2x media,
the data will be unreliable since the media cannot support writing
at this speed. Therefore, to avoid 4x writing on a 2x disc there
is information written on the disc about the proper rewriting speed.
In addition, RW media from RICOH, that do not have markings indicating
acceptable writing speeds (1x2x4x) on the printed side, will only
support 2x writing.
3.)
Why
does the CD-RW disc capacity decrease to about 530 MB from 650 MB
after the disc is formatted with Direct CD 2.5?
For packet writing, it is necessary that
the disc be formatted. The formatting process involves writing the
index information of each packet* of the whole disc. In addition,
the formatting requires additional space for linking blocks as a
connection between the index information of each packet.
Formatting for packet writing will require some disc space, though
the size depends on the software and the version.
* Packet : a minimum recording unit
4.)
What
does 'Orange Book' mean?
The Orange Book contains the standards defined
for the recordable/rewritable CD media. It is made up of three parts.
In Part I; the standard applied to MO for CD is described, though
this is not used at present. The main standards are Part II for
CD-R and Part III for CD-RW. Each Part of these standards provides
information about the signal characteristics for both a blank disc
(an unrecorded disc) and a recorded disc, the mechanical characteristics,
and the optical characteristics of a disc.
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