EXP Computer EXP CD-Rewriter Bundled S_W - Manual (Page 121)

Glossary
Glossary-7
cording session. If data is linked
between sessions, all data on a
multisession CD, when read on a
multisession CD-ROM drive,
may be seen as part of a single,
logical structure.
O
Optimum Power Calibration Area
The optimum calibration area
(OPC), is a special area near the
center of the recordable CD. Be-
fore writing a track on a CD, the
CD recorder must adjust the
amount of power applied to the
writing laser for the optimum
level for the mounted CD. The
optimum calibration area is re-
served for this purpose.
On-the-Fly
Writing data directly from the
source files to CD without first
writing a real ISO 9660 disc
image.
Orange Book
The Philips/Sony specification
for Compact Disc Magneto-
Optical (CD-MO) and Compact
Disc Write-Once (CD-WO)
systems. It is the standard by
which recordable CDs are
recorded.
P
Packet Writing
A method of CD recording in
which data can be written in
much smaller chunks than are
possible with the current Disc-at-
Once and Track-at-Once
methods.
PCA
Power Calibration Area. A space
reserved at the beginning of a re-
cordable CD for calibrating the
recorder's laser for that particu-
lar CD.
Photo CD
A CD format based on the
CD-ROM XA and Orange Book
specifications. It is used to store
photographic images for display
and printing.
PMA
Program Memory Area. On a re-
cordable CD, an area which tem-
porarily contains track numbers
and their starting and stopping
points (that is, the session Table
of Contents) when tracks are
written in a session that is not yet
closed. When the session is
closed, this same TOC informa-
tion is written in the session
lead-in.
Post-Gap
A space dividing tracks, record-
ed within the track data area at
its end. The post-gap is 150 sec-
tors (2 seconds) long and is re-
quired only where successive
tracks are of different types.
However, because many disc
replicators expect a post-gap at
the end of every track and may
erroneously strip out data sec-
tors if they do not find one, Easy
CD software records a post-gap
after every track.
Pre-Gap
A space dividing tracks, record-
ed before the track data area. The
length of the pre-gap varies with
the CD recorder, the types of
tracks being recorded, and
whether recording is done in
Track-at-Once or Disc-at-Once
mode.