Hardware Reference
In-Depth Information
Orange Book
The Orange Book defines the standards for recordable CDs and was announced in 1989
by Philips and Sony. The Orange Book comes in three parts. Part I describes a format
calledCD-MO(magneto-optical),whichwastobearewritableformatbutwaswithdrawn
before any products really came to market. Part II (1989) describes CD-R, and Part III
(1996) describes CD-RW. Note that originally CD-R was referred to as CD-WO (write-
once), and CD-RW originally was called CD-E (erasable).
The Orange Book Part II CD-R design is known as a WORM format. After a portion of
a CD-R disc is recorded, it can't be overwritten or reused. Recorded CD-R discs are Red
Book and Yellow Book compatible, which means they are readable on conventional CD-
DA or CD-ROM drives. The CD-R definition in the Orange Book Part II is divided into
twovolumes.Volume1definesrecordingspeedsof1x,2x,and4xthestandardCDspeed;
the last revision, dated December 1998, is 3.1. Volume 2 defines recording speeds up to
48x the standard CD speed. The latest version released, 1.2, is dated April 2002.
Orange Book Part III describes CD-RW. As the name implies, CD-RW enables you to
erase andoverwrite information inaddition toreading andwriting. TheOrangeBookPart
III CD-RW definition is broken into three volumes. Volume 1 defines recording speeds
of 1x, 2x, and 4x the standard CD speed; the latest version, 2.0, is dated August 1998.
Volume 2 (high-speed) defines recording speeds from 4x to 10x the standard CD speed;
thelatestversion,1.1,isdatedJune2001.Volume3(ultra-speed)definesrecordingspeeds
from 8x to 32x; the latest version, 1.0, is dated September 2002.
Besides the capability to record on CDs, the most important feature instituted in the
Orange Book specification is the capability to perform multisession recording.
Multisession Recording Overview
BeforetheOrangeBookspecification,CDshadtobewrittenasasinglesession.A
session
is defined as a lead-in, followed by one or more tracks of data (or audio), followed by
a lead-out. The lead-in takes up 4,500 sectors on the disc (1 minute if measured in time
or about 9.2MB worth of data). The lead-in also indicates whether the disc is multises-
sion and what the next writable address on the disc is (if the disc isn't closed). The first
lead-out on a disc (or the only one if it is a single session or Disk At Once recording) is
6,750sectorslong(1.5minutesifmeasuredintimeorabout13.8MBworthofdata).Ifthe
disc is a multisession disc, any subsequent lead-outs are 2,250 sectors long (0.5 minutes
in time or about 4.6MB worth of data).
A multisession CD has multiple sessions, with each individual session complete from
lead-in to lead-out. The mandatory lead-in and lead-out for each session do waste space
on the disc. In fact, 48 sessions would literally use up all of a 74-minute disc even with
