- A CD-ROM multimedia system owned by Matsushita. M2 as a replacement
will be available soon.
- This is a character set used in the ISO 9660 Volume Descriptors
consisting of capital A to Z, digits 0 to 9, and the following symbols:
(space)! " % & '()=*+,-./:;<?>_
- A-Time (Absolute time)
- Is the time elapsed from the beginning of the an audio CD in minutes
and seconds. A-Time access involves mapping the audio portions relative
to the beginning of the disc in the CD-ROM (start and stop of each)
using time addresses (Min-Sec-Sector). This allows random access
of audio or video segments. Used for programming an application on
a mixed-mode disc measuring from the very beginning
of the data area (including the computer data in Track 1). The timecode
is contained in the subcode Q-channel as minutes, sectors
and frames measured from the beginning of the disc.
- Dolby's surround sound digital audio system, specified for NTSC
DVD video discs.
- Access Time
- The time it takes to retrieve a piece of information. With hard
disks or compact discs, maximum access time is measured as the time
it takes to move from one end of the disc to the other, find a piece
of information, and transfer that information to RAM.
- Active Movie
- Released by Microsoft in 1996, Active Movie, is the replacement
for Video for Windows and Media Control Interface. The 32-bi architecture,
enhanced video playback capabilities (higher frame rates) should
enhance MPEG-2 video.
- Adapter cards
- Used in computers to attach peripheral devices to the PC. The cards
installed into spare slots on the motherboard.
- Adaptive Differential Pulse Code Modulation is a compression algorithm
which take half the space of PCM. Works by recording the predicted
value of the signal instead of the absolute value of original waveform.
- The chemical symbol for aluminum. Aluminum is is used for the reflective
layer on CD and DVD discs.
- Image distortion caused by a signal sampling at low resolutions.
Diagonal lines appear stepped - like staircase.
- Amaray Case
- The plastic case for DVD disc.
- Amiga CD32
- The Commodore multimedia based CD-ROM console.
- Physical variable such as voltage and current represented by numerical
values. These devices generally have dials and sliding mechanisms.
- Analogue Video
- A signal that represents video. There are infinite smooth gradations
between given video levels. Digital video has a finite set of levels.
- Analog Signal
- A signal that is constant rather than discrete nature or pulsed.
The analog signal is used to reflect the variation in a physical
phenomena - light, heat, position, pressure or sound. Note: To be
used in computers the analog signal must first be converted into
a digital signal.
- Analog to Digital Converter (A/D)
- A device that samples an analog signal at regular intervals and
quantizes each sample, that is, represents each sample's value with
a binary number of some predetermined length. Analog-to-Digital conversion
samples analog signals to produce a digital signal that describes
the original analog signal.
- The method of fitting a wide-screen format into a traditional 4:3
aspect ratio (TV).
- The ability to view a single screen from multiple camera angles.
This is a DVD feature.
- A tape recorded with a file structure and tape label system which
defines the Volume name and file header for the information contained
in the tape, according to ANSI (American National Standards Institute)
specification X3.27-19778. Most disc manufacturers prefer ANSI-labeled
- A tape recorded with a file structure, but without the ANSI tape
Advanced SCSI Programmer's Interface. Set of software
primitives and data structures which allow software using the ASPI
interface to be SCSI host adapter-independent.
- A method of providing smooth transition from pixels. A form of
interpolation is used.
- Application Program Interface: allows a program application to
communicate with the operator.
- In terms of computers, application refers to software designed
to perform a specific task on a computer.
- Analogue Protection System: A copy protection for DVD that distorts
the output to video so that it can not be recorded and played back
on VHS. Developed by Macrovision.
- A visual distortion in an video image that is unwanted.
- The American Standard Code for Interchange of Information is a
character set consisting of 128 text characters (abc...) ASCII (askey)
was implemented as the standard for communications, and mini and
- Advanced SCSI Programmer's Interface. It defines
a set of software primitives (command) and data structures or an
application to use when communicating with SCSI host
adapters to be SCSI host adapter-independent. This
is essentially a driver.
- Aspect Ratio
- An image's width to height ratio. Example would be 16:9 - wide
screen format or 4:3 regular T.V. format. On computers this is a
relationship between width and height of pixels in an image.
- The IDE/ATAPI is a data interface that often is provided by PC
manufacturers and, is generally included when you purchase a new
computer. Usually, the computer motherboard comes with a primary
and a secondary IDE bus. Up to two IDE/ATAPI devices, a master and
a slave, can be connected to each bus. Because this interface is
less sophisticated than the SCSI one, ATAPI devices
are usually more affordable. Note, however, that often IDE/ATAPI
devices are slower and, particularly in case of CD-Readers, less
accurate. If you are considering using DiscJuggler with multiple
recorders, SCSI is the preferred bus.
- Audio signals were recorded and reproduced using analog signals
- LP records, tape etc. Computers convert all analog signals into
digital code. The quality of the sound is determined by the bit-rate
(or the sampling rate.) The higher the rate the large digital code
- The directory name for audio files in a DVD volume using
the Universal Disk Format.
- The creation of courseware (application) which combines graphics,
audio, video, and/or text. When you have finished creating your application
with an authoring software, you can use CD recording software such
as Nero Burning ROM to write it to CD.
- Auto Insert Notification
- A file on a disk that tells Windows how to treat the CD. The AIN
is most often used to auto launch a program on a CD.
- CD Audio
- Standard CD format for storing audio soundtracks. For example,
music and songs.
- Average Access Time
- The amount of time it takes a CD-ROM/CR-R/CD-RW to find a random
piece of information. This is generally used measure the performance
of a CD Drive; however, many factors need to be considered when looking
at the performance of CD Drive.
- In terms of computers this indicates the amount of information/traffic
per unit of time. Generally expressed in megabytes per second.
- A set of bars in the inner ring of a CD used to identify the CD.
- Bidirectional Prediction
- The Codec (coder-decoder) tracks what has been processed while
reading ahead to prepare appropriate actions. This enables efficient
processing of burst in data transfer rates. Bidirectional prediction
is implemented in compression and the decompression procedures.
- Binary Code
- A code where the elements can assume either one of two possible
states. Computers use 0s and 1s to form the code into bytes. Storage
devices mediums are coded with binary files. CDs, for example use
pits to represent the binary code. The CD ROM will read the pits
and convert them into 0s and 1s and eventually into music or data.
Double refraction of light in a crystal: the splitting of incident
light into two rays with polarisations at right angles to each
other and causing two images to appear, e.g. in calcite
For Optical devices, CDS/DVDs, it means double refractive ability.
This is generally caused by improper cooling of the substrate material
(glass). This is an unwanted effect as it will cause errors in
reading of the CD.
- A compressed form of 'binary digit.'
- BLER stands for Block Error Rate - the "raw" digital
error rate before any error correction, which in turn is a determining
factor in the quality and readability of a given disc.
- A unit of 252 bytes as defined in the Yellow Book.
- Blue Book
- The CD Extra standards book.
- Memory that holds momentarily information/data which is directly
available to the CPU. Buffers are a solution to speed differences,
interface delays, and other variations between a device and CPU.
- Buffer Underrun
- An uninterrupted stream of data is required by the CD Recorder
during a recording session. If the stream becomes insufficient
or is interrupted during the session and the buffer is unable to
provide the pick-up the shortfall the recording will stop and report
a buffer underrun.. See also "About Buffer Underruns."
- Burst Error
- Errors detected in consecutive data bits on compact discs often
caused by scratches, fingerprints, or other physical defects on a
disc. Error correction codes are designed to compensate for the anticipated
frequency and duration of burst errors.
- A portion of RAM used for temporary storage of data which must
be accessed very quickly. In applications which run from CD-ROMs,
the cache is typically used to store directory files.
- The loading device for CD players/Recorders..
- PCA or Program Calibration Area. Space at the beginning of the
CD for calibrating the laser to read or write to the CD.
- CDs - The capacity of a CD depends on many factors. Capacity is
generally measured in Mbytes or minutes. CDs hold from 63 to 80 minutes
of data (music) or 650 Mbytes.
DVD - Capacity of a DVD ranges from 4.76 GB (single side - single
layer) to 17.0 GB (double-side - double layer)
- CD Bridge
- Specifying a way to record CD-I information on a CD-ROM XA. This
is used for Photo CD and Video CD.
- CD+Graphics. Audio, text and graphics used in the same application.
This type of disc is usually used for Karaoke machines.
Compact Disc-Digital Audio. A CD-DA disc contains tracks with
Audio sectors only.
In 1982 Philips and Sony introduced the necessary technology for
storing digital audio signals on a Compact-Disc, and introduced
the CD-Digital Audio.
- CD Extra/CD Plus
- In track 1 data and/or graphics are included. This addresses problems
of Mixed-mode disc. This is a format that uses the
- A compact disc format designed to allow interactive multimedia
applications to be played through a computer/disc player attached
to a television. Especially good for real-time animation, video,
and sound. The CD-I standard is called the Green Book.
- CD-R [disc]
- An acronym for compact disc-recordable which is a type of media
that allows you to record information using a CD Recorder.
- Compact Disc-Read Only Memory. A standard for compact disc to be
used as a digital memory medium for personal computers. The specifications
for CD-ROM were first defined in the Yellow Book.
- CD-ROM disc
- A CD-ROM disc contains only data sectors as defined
in the Yellow Book.
- CD-ROM Drive
- A peripheral device attached to a computer which allows it to read/play
a CD-ROM disc. All CD-ROM players can also play back audio CDs, but
you need external headphones or speakers to hear them.
- CD-ROM XA (CD-XA)
- "XA" stands for Extended Architecture. CD-ROM XA is an
extension of the Yellow Book standard, generally consistent
with the ISO 9660 logical format but designed to add
better audio and video capabilities (taken from the CD-I standard)
so that CD-ROM can more easily be used for multimedia applications.
CD-ROM XA is also the physical format for Photo CD discs.
- Compact disc-rewritable. The most recent addition to the compact
disc family. It was originally called "CD-Erasable." The
official name is CD-ReWritable, and it is a media and recording system
that allows the user to erase previously recorded information and
then record new information onto the same physical location on the
disc. See "What is CD-ReWritable?" article.
- CD-Text - Philips' standard for encoding disc and track data on
audio CDs - adds text information to a conventional audio CD, enabling
music CDs to be read as well as listened to. The text displayed could
be the artist's name, album title and track title, for example. The
disc is fully compatible with the 500 million audio CD players around
the world, which will simply play the music and ignore the text
- Compact Disc-Write Once. Recordable compact disc.
- CD Bridge
- A set of specifications defining a way of recording CD-Information
on a CD-RO disc. Used for Photo CD and Video
- CD Duplication
The process of making one or more copies of a compact disc. CD
Extra or CD Plus
Enhanced CD - includes two sessions, the first containing "n" (up
to 98) audio tracks, and the second session containing
a CD-ROM XA format data track. Additional characteristics are defined
in the Blue Book standard.
- CD Image File
- A file containing an exact representation of the data that will
be placed on the CD-ROM. CD Image files are often written as the
first step in the pre-mastering process when the complexity of the
disc makes "On-the-fly" recording impossible. In these
cases the CD Image file is created from the source data on the hard
disk then transferred to the CD Recorder.
- Cross-Interleaved Reed-Solomon Code. The basic level of error correction
provided for Audio CD with one uncorrectable bit out of every 109.
CD-ROM provides additional protection for data (ECC/EDC), reducing
the error rate to one bit in 1013.
- Close disc
- To "close" a recordable disc so that no further data
can be written to it. This is done when the last session's
lead-in is written - the next writeable address is not recorded in
that lead-in, so the CD recorder in subsequent attempts to write
has no way of knowing where to begin writing. It is NOT necessary
to close a disc in order to read it in a normal CD-ROM drive.
- Close Session
- When a session is closed, information about its contents
is written into the disc's Table of Contents, and a
lead-in and lead-out are written to prepare the disc for a subsequent
- Compact Disc
- CD stands for compact disc which is a general term for all formats
of CD media. CD formats available on the market now include CD Audio,
CD-ROM, CD-ROMXA, VideoCD, CD-I and others.
- Compact Disc Formats
During the last two decades several Compact Disc formats were
developed to serve different purposes and uses. Starting with the
CD-DA format in 1980, as a way to distribute high quality music
in a compact and convenient format, the first compact disc standard
was formulated. Then, the idea of storing computer data on the
same media, more than 10 years ago, lead to a new format: the CD-ROM
(along with CD-DA the most important ever invented). In the last
few years, the desire to store a whole new generation of multimedia
contents (audio, video, games, pictures etc.) demanded new formats:
CD-I, CD-XA, Photo-CD, Video-CD, CD+ etc. were invented.
Compact Disc Recording & Data Throughput
Because a CD-Writer is a real-time device, it places special demands
on a computer and its peripherals. For a CD Recorder to successfully
create a compact disc, it must receive an uninterrupted flow of
data that must be transferred at a speed equal to or greater than
the recording speed of the CD Recorder. For CD Recorders operating
in single-speed (1x) mode, data must be transferred at a continuous
rate of 150 KB per second for data, and ~172 KB per second for
audio. For CD Recorders operating in double-speed (2x) mode, data
must be transferred at a continuous rate of 300 KB per second for
data, and ~344 KB per second for audio. For CD Recorders operating
in quadruple-speed (4x) mode, data must be transferred at a continuous
rate of 600 KB per second for data, and ~689 KB per second for
audio. Data transfer rates in the range of 150 to 600 KB per second
are well below the data transfer rates claimed by hard disk manufacturers.
However, slow CPU or SCSI bus performance and sub-optimal
hard disk performance may combine to reduce the actual sustained
data transfer rate below the transfer rate requirement of double-speed
or quadruple-speed CD Recorders.
- A process that entails blocking user data and adding information
identifying each block. Formatting information includes
the data address and synchronization information and may include
error correction check sums and data and data type specification.
- Cue Sheet
- In Easy-CD Pro for Windows 3.1, a list of tracks which will be
written one after the other in the same session without
user intervention. Generally used to create multi-track audio or mixed-mode discs.
- A character set used in ISO 9660 filenames, if the standard is
strictly adhered to. Consists of capital A to Z, digits 0 to 9, and
the underscore symbol ( _ ).
- See Digital to Analog Converter.
- See Disc-at-Once.
- Data Area
- In ISO 9660, the space on a CD-ROM where the user data is written.
It begins at the address 00:02:16.
- Data Formats
- Three different types of data can be recorded on CD. They all share
the same physical block size (2352 bytes). However,
they have different user block sizes (bytes effectively available
to the user) depending on the level of error correction adopted:
the lower the read accuracy required, the smaller the error correction
code required, the bigger the user data block is. The following is
a list of CD compatible data formats:
- Audio: No extra error correction is required to read and play
back audio. The user block size matches the "physical" block
size and is 2352 bytes.
- Mode 1/Form 1: Mode 1 and Mode 2/Form 1 formats are used to
store digital data therefore the highest read accuracy is required.
The user block size is 2048 bytes (2KB). The remaining bytes
are used to store sync patterns, block headers and error correction
and detection codes (ECC/EDC).
- Mode 2/Form 2: This format is used almost exclusively to store
digital video data, thus requiring only moderate read accuracy.
The user blocks size is 2324 bytes. The remaining bytes are used
to store sync patterns, block headers and error detection codes
- Digital Audio Extraction (DAE)
- The process of copying CD-DA audio tracks digitally from your CD-Writer
or another CD-ROM drive, to hard disk or to recordable CD. Not all
CD-ROM drives support this!
- Digital to Analog Converter (D/A)
- A device (DAC) that converts digital numbers to an analog signal.
In a CD Audio player the DAC takes the stream of numbers read off
of the disc and produces an analog audio signal.
- Disc-at-Once (DAO)
- A method of writing in which one or more tracks are written in
a single operation. The laser will not stop until the whole disc
recording is finished and the disc is closed -- hence no Run blocks
and no clicks between audio tracks. (See also Track-at-Once.) Disc-at-Once
has only been added/available with the recent generation of CD recorders
and recent firmware upgrades. For more information, read "disc-at-Once,
Track-at-Once and Packet Writing".
- See UPC.
- Error Correction Code. A system of scrambling data and recording
redundant data onto disc as it is premastered. On playback,
this redundant information helps to detect and correct errors that
may arise during data transmission.
- Error Detection Code. 32 bits in each sector which
are used to detect errors in the sector data.
- Extended Architecture
- See CD-XA.
- File System
- A data structure that translates the physical (sector)
view of a disc into a logical (files, directories) structure, which
the application and user can more easily use to locate files. See
also Logical Format.
- Gold Disc
- The recordable disc used in recordable CD systems. The blank disc
is made of a bottom layer of polycarbonate with a preformed track
spiral which the recording laser follows when inscribing information
onto the disc. This type of disc is therefore also called pre-grooved.
A translucent layer of recordable material is laid on top of the
polycarbonate, then a reflective layer of gold. On top there are
thin layers of lacquer and label.
- Header Field
- Four bytes recorded at the beginning of each sector which
tell the address of the sector (expressed as a Logical Block Number)
and the mode in which the sector is recorded.
- The file system used by the Macintosh operating system to organize
data on hard and floppy disks. Can also be used for CD-ROMs.
- High Sierra Format
- The standard logical format for CD-ROM originally
proposed by the High Sierra Group, on which the ISO 9660 standard
is based; essentially identical to ISO 9660. High Sierra is no longer
- Under the Orange Book standard for recordable CD,
hybrid means a recordable disc on which one or more sessions
are already recorded, but the disc is not closed, leaving space open
for future recording. However, in popular use, the term "hybrid" often
refers to a disc containing both DOS/Windows and Macintosh software,
which on a DOS/Windows platform is seen as a normal ISO 9660 disc,
while on a Mac it appears as an HFS disc.
- ISO 9660 Format
- An internationally accepted standard specifying the logical
format for files and directories on a CD-ROM. The standard
allows different computers with different operating systems to
access the same data format.
- ISO 9660 Image
- Or CD-ROM image, image, disc image. A single large file which is
an exact representation of the whole set of data and programs as
it will appear on a CD, in terms of both content and logical format.
- ISO 9660 Interchange Levels
These are three methods of recording and naming files on disc
under the ISO 9660 standard. There are three nested, downward-compatible
In Level 1 (the most restrictive):
- Each file must be written on disc as a single, continuous stream
of bytes -- files may not be fragmented or interleaved.
- A filename may not contain more than eight d-characters.
- A Filename Extension may not contain more than three d-characters.
- A directory name may not contain more than eight d-characters.
In Level 2, again, each file must be written on disc as a single,
continuous stream of bytes.
In Level 3 there are no restrictions.
- International Standard Recording Code. Some recorders allow the
ISRC to be recorded for each audio track on a disc. The code is made
up of: Country Code (2 ASCII characters), Owner Code (3 ASCII characters),
Year of Recording (2 digits), Serial Number (5 digits).
- Incremental Multisession
- Incremental Multisession uses pointers in each session
to link all the sessions together. These links enable you to access
the latest information, starting from the last session on a disc.
- One of the possible causes of disc recording error, jitter is actually
defined as a "timing problem." Simply, jitter is the result
of pits on a disc being or appearing to be too short or too long,
based on a certain clock cycle. For example, pits on a disc can range
from what is called a "3T" pit to an "11T" pit.
If a pit that was intended to be written as 3T varies or is perceived
to vary from the length of a 3T pit beyond a certain time period,
it can be interpreted incorrectly, resulting in a possible disc error.
This deviation is known as "jitter." The same is true for
- Joliet is an extension of the ISO 9660 standard, developed by Microsoft
to allow CDs to be recorded using long filenames, and using the Unicode
international character set. Joliet allows you to use filenames up
to 64 characters in length, including spaces. Joliet also records
the associated DOS-standard name for each file so that the disc may
be read on DOS systems or earlier versions of Windows. The number
of characters allowed in a long file name is up to 64, and the number
of characters in the long file name plus its file path cannot exceed
- Land Jitter
- See Jitter
- An area at the beginning of each session on a recordable
compact disc which is left blank for the session's Table of
Contents (track numbers and start-and-stop points) and other
miscellaneous information about the disc and about the recorded tracks.
The lead-in is written when a session is closed, and takes up 4500 sectors
on disc (1 minute, or roughly 9 megabytes). The lead-in also indicates
whether the disc is multisession and, if the disc is
not closed, which is the next recordable address on the disc.
- An area at the end of a session which indicates that
the end of the data has been reached; there is no actual data written
in the lead-out. The first lead-out on a disc is 6750 sectors
(1.5 minutes, about 13 megabytes) long; any subsequent lead-outs
are 2250 sectors (.5 minute, about 4 megabytes).
- Link Area or Link Blocks
- See Run-in/Run-out Blocks below.
- Linked Multisession
- A disc containing more than one session, in which
all of the data in the various sessions on disc can be seen as if
it had all been recorded in one single, large session. To link sessions
in Easy-CD Pro 95, you must check a box in the Load Contents tab.
In Easy-CD Pro for Windows 3.1, use Load Contents.
- Logical Block
- The smallest addressable space on a disc. Each logical block is
identified by a unique Logical Block Number (LBN), assigned in order
starting from 0 at the beginning of the disc. Under the ISO 9660
standard, all data on a CD is addressed in terms of Logical Block
Numbers. At present, CD recording is supported at one Logical Block
per logical sector.
- Logical Format/Logical Structure
- A logical file format such as ISO 9660 translates the sector-by-sector view
of a compact disc into a virtual "tree" of directories
and files, which makes it easier for both humans and computers to
use the information on the disc.
- Technically, refers to the process of creating a glass master from
which compact discs will be reproduced in quantity. In desktop recordable
CD systems, mastering is done together with premastering by
the desktop CD recorder, and the term is generally used to mean "recording."
- Motion Picture Experts Group, whose name has been applied to the
standard promulgated by the group for compression of full-motion
- Microsoft DOS extensions for CD-ROM. Allows the DOS operating system
to recognize a CD-ROM as a DOS volume.
- Mixed-Mode disc
- A compact disc including both computer data (CDROM tracks) and
audio (CD-DA) tracks. The data is all contained in Track 1, and the
audio in one or more of the following tracks.
- To install a compact disc so that the computer recognizes its presence
and can read data from it.
- MultiRead is an OSTA specification that recognizes the importance
of having future CD readers capable of reading a wide variety of
CD-based media compared to older generations of CD readers. MultiRead
CD-ROM drives, for instance, will be able to read newer CD-RW media
as well as CD-R and CD-ROM.
- Multisession disc
- If a disc contains more than one session, then the
disc is called a Multisession disc. It is a compact disc to which
data is added incrementally in more than one recording session. If
data is linked between sessions, all data on a multisession disc,
when read on a multisession CD-ROM drive, may be seen as part of
a single logical structure.
- Multi-volume is used to organize multiple sessions as completely
separate volumes, each with its own directory of information.
- On the Fly
- To write on-the-fly means to write to CD data referenced in a virtual
CD image without first writing a real ISO 9660 image.
- Optimum Power Calibration (OPC)
- OPC is found in the newer 8X CD-R drives. 4X drives, for example,
calibrate the laser at the beginning of the CD and then use the fixed
laser power across the entire CD surface. The OPC circuit allows
the laser outp8ut power to continuously adjust to the CD surface
throughout burning. CD-Rs produced with OPC show the lowest BLER rates
ever - less than 5 on most CDs.
- Optimum Power Calibration Area
- (OPC Area) The optimum calibration area is a special area near
the center of the recordable disc. Before writing a track on a disc,
the CD recorder must adjust the amount of power applied to the writing
laser for the optimum level for the mounted disc. The optimum calibration
area is reserved for this purpose.
- Orange Book
- The Philips/Sony specification for compact disc Magneto-Optical
(CD-MO) and Write-Once (CD-WO) systems - in other words, the standard
by which recordable CDs are recorded.
- P-Q Editing
- Subchannels that can be manipulated, when recording in disc-at-once
mode, which give the user control over the P through Q subchannels
for optimal glass mastering.
- Packet Writing
- A method of writing data on a CD in small increments, as opposed
to writing large blocks of information as required by the Track-at-Once
and disc-at-Once methods. Packet writing (also "packet resourcing")
allows small packets or pieces of data to be written one packet at
a time, lessening the chance of buffer underrun. Packet writing is
good only for data tracks.
- Path Table
- The Path Table contains the addresses for the Directory Files so
that they can be used to directly access the data files.
- (Power Calibration Area). A space reserved at the beginning of
the disc for calibrating the laser power needed to record to that
- Photo CD
- A compact disc format based on the CD-ROM XA and Orange Book Hybrid
disc specifications, used to store photographic images for display
- Pit Jitter
- See Jitter
- (Program Memory Area) On a recordable disc, an area which "temporarily" contains
the information about the recordings on the disc -- track numbers
and their starting and stopping points when tracks are written in
a session which is not yet closed. When you do not
close the current session, to keep track of all data recorded, a
kind of pre-TOC is written to the disc in an area that is only accessible
by the CD recorder. When the session is closed, this same TOC information
is written in the session lead-in.
- A space dividing tracks, recorded within the track data area at
its end. The post-gap is 150 sectors (2 seconds) long
and is required 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 sectors
if they do not find one, Easy-CD Pro Software records a post-gap
after every track. See also "About Gaps Between Tracks".
- A space dividing tracks, recorded before the track data area. The
length of the pre-gap varies with the CD recorder and the types of
tracks. Where successive tracks are both of data, one track is separated
from another by a track pre-gap of 150 sectors (2 seconds).
Where successive tracks are of different types, the pre-gap is usually
of 225 sectors (or three seconds). If two successive
tracks are audio, there may be no pre-gap at all. See also "About
Gaps Between Tracks".
- The process of preparing data to be recorded onto a compact disc.
This includes breaking the data into sectors and recording
those sectors with the appropriate header (address) and error correction
information. In the case of recordable CD systems, premastering and mastering are
done in one operation, resulting in a ready-to-read compact disc.
- Primary Volume Descriptor
- The PVC or Primary Volume Descriptor, can always be found at the
16th sector of each data session. It
is the hook of the file system to the medium. It refers to the Path
Table and to the Root Directory.
- Real CD Image
- A Real CD Image can also be called a Physical ISO Image. This refers
to a file that exactly duplicates how data will appear on the CD
in ISO 9660 format. Since a Real CD Image contains the actual contents
of the source, it requires the same amount of disc space as the CD-ROM
disc to be created.
- Red Book
- The Philips/Sony specification for audio (CD-DA) compact discs.
- Windows-95 long file names only -- up to 128 characters. Also a
file naming option in Easy-CD 95 Software and Easy-CD Pro 95 Software
which allows you to write files to disc with names up to 128 characters
long, including spaces. This is not part of the Joliet standard,
the Unicode character set is not supported, and there is no provision
for associated DOS filenames. Romeo filenames can be read on Windows
95 and NT systems. Romeo discs can be read on Macintosh systems if
the filenames are not longer than 31 characters. Do not use Romeo
if your disc must be read in other conditions.
- Root Directory
- The Root Directory is a special Directory File in that no other
Directory File refers to it.
- Run-In/Run-Out Blocks
- When the recording laser is turned off after writing, two run-out
blocks are written. When it is turned back on again, five run-in
blocks are written. These seven blocks are also known as link blocks.
- Small Computer System Interface (pronounced "scuzzy").
A standard for high-speed data transfer between computers and their
peripheral devices. A SCSI interface allows up to eight different
peripheral devices to be connected to a single controller.
- The smallest recordable unit on a CD. A disc can contain [(75 sectors
per second) x (60 seconds per minute) x (number of minutes on disc)]
sectors. The amount of data contained in the sector depends on what
physical format and mode it is recorded in; for "regular" CD-ROM
(Mode 1) data, you can fit 2048 bytes (2 kilobytes) of data into
- As defined in the Orange Book, a Session is an area
on the disc consisting of a Lead-In Area, a Program Area and a Lead-Out
Area; a recorded segment of a compact disc which may contain one
or more tracks of any type (data or audio).
- Table of Contents (disc)
- Shows the number of tracks, their starting locations, and the total
length of the data area of the disc.
The Table of Contents (TOC) contains information
about the disc and tracks. When you close the current session,
the Table of Contents will be written in the Lead-In Area. With
an unfinished (unclosed) recording of the disc, however, the TOC
cannot be written to the disc.
Every time you write to CD, you will create at least one track,
which is preceded by a pre-gap and followed by a post-gap.
Any session may contain one or more tracks, and the
tracks within a session may be of the same or of different types
(for example, a mixed-mode disc contains data and
With Track-at-Once writing mode, a CD-Recorder will record one
track at a time. In between every two tracks (unless you are only
recording a single track). The CD-Recorder laser will stop while
the hard disc prepared for the contents of the next track.
Each time the laser is stopped, it writes Run-Out blocks. When
starting again, it writes Run-In blocks (a total
of 7 blocks). These are ignored by CD-ROM readers and so do not
disturb data transmission, but in some audio players you might
hear a click between tracks. This is why disc-at-Once recording
is preferable for audio discs.
- Universal Product Code. With some CD recorders, you may define
a thirteen-digit UPC catalog number for the entire disc, which will
be written in the disc's Table of Contents. Also known
- Video CD
A VideoCD disc may include video clips converted from MPEG files
and still images converted from BMP, GIF, JPEG, PCX, TIFF or TGA
files. The video clips must conform to the MPEG for
VideoCD specification defined in the White Book.
VideoCD is a reproduction system to present full motion pictures
with associated audio by using the compact disc format. The video
and sound are compressed together using the MPEG 1
standard and recorded onto a CD Bridge disc.
A Video CD disc contains one data track recorded in CD-ROM XA
Mode 2 Form 2. It is always the first track on the disc (Track
1). The ISO 9660 file structure and a CD-I application program
are recorded in this track, as well as the Video CD Information
Area which gives general information about the Video CD disc.
After the data track, video is written in one or more subsequent
tracks within the same session. These tracks are also recorded
in Mode 2 Form 2. The session is closed after all tracks have been
- Virtual CD Image
- A Virtual CD Image is an ISO-formatted directory database that
indicates how files will be arranged on your CD. The image contains
pointers to where those to-be-recorded files actually reside on your
drives, while the actual contents of the files or directories are
still on the original storage media.
It also refers to a database of files to be written to CD with
Easy-CD Pro for Windows 3.1, created by dragging & dropping
files into the main window. It can be used to write directly to
CD on-the-fly or to record a real ISO 9660 image to hard disk.
- Under the ISO 9660 standard, a single CD-ROM disc.
- Volume Descriptors
- In ISO 9660, a set of information on the disc containing vital
information about the CD and how the computer should read it.
- Yellow Book
- The book which sets out the standard developed by Philips and Sony
for the physical format of compact discs to be used for information
- A Wave file (.WAV) is a type of sound file which stores digitized