Can I just copy files onto a CD-R like I would to a floppy?
The process of writing to a CD-R can be a bit more involved than
copying files to a floppy. Burning a CD-R requires CD-R burning
software. Some CD-R writer comes with bundled CD-R burning software
(such as the PrimoCD Plus). With "packet
writing" software, and a writer that supports it, you can
treat a CD-R disc like a floppy. For CD-R, you can only write
to each part of the disc once, and you cannot reclaim the space
used. There are other limitations in writing to a CD-R as well.
With common software, it usually ends up writing everything to
the disc all at once, if you want good compatibility. Also, when
the writing is in progress, you cannot interrupt the drive, otherwise
it will be un-readable. If you want to write your files in smaller
bunches, a fair bit of space will be lost every time you stop
and start again.
What are the methods of writing to a CD-R?
There are three basic methods for writing to a compact disc: Track-at-Once
(TAO), Disc-at-Once (DAO),
and Packet Writing.
In Track-at-Once recording, the recording laser is turned off
after each track is finished, and on again when a new track must
be written, even if several tracks are being written in a single
recording operation. Tracks recorded in Track-at-Once mode are
divided by gaps. If a data track is followed by an audio track,
the gap is 2 or 3 seconds. The gap between audio tracks is usually
2 seconds. There is nothing that can be done by the software to
suppress or reduce the gap, unless both recorder and software
support variable-gap Track-at-Once. All current CD recorders support
Track-at-Once Some newer recorders allow you to set the size
of the gap between tracks in Track-at-Once mode. For example,
Toast uses variable-gap Track-at-Once to allow the setting of
the size of the gap, from near-zero (2 sectors, or 2/75 of a sec)
to 8 seconds, before each audio track on an audio disc.
Opposite to Track-at-Once (TAO) that allows writes to be made
in multiple passes one track at a time, Disc-at-Once (DAO) writes
the entire disc in one pass. The entire writing must completed
with out interruptions. In Track-at-Once mode, there is additional
overhead due to the area required for laser stops and starts.
In Disc-at-Once recording, one or more tracks are recorded without
ever turning off the recording laser, and the disc is closed.
Disc-at-Once recording requires a blank disc, and cannot be used
for multisession. Not all CD recorders are designed to support
Disc-at-Once recording, and some which are supposed to support
it need firmware upgrades. For example, the CD Copier included
with Easy CD Creator does not currently support Disc-at-Once.
Toast 3.x does not support Disc-at-Once; Toast 4 and Jam do. Disc-at-Once
is primarily needed to record audio discs with a variable (or
no) gap between tracks.
Session-at-Once is used primarily for CD Extra. In Session-at-Once
recording, a first session containing multiple audio tracks is
recorded in a single pass, then the laser is turned off, but the
disc is not closed. Then a second (data) session is written and
Writing Packet writing is a method of writing data on
a CD in small increments. Not all CD recorders support packet
writing. Not all current CD-ROM drives can read packet-written
discs. Packet writing is a feature which must be built into the
and Variable-Length Packets There are two kinds of packets:
fixed-length and variable-length. Fixed-length packets are more
suitable for CD-RW in order to support random erase, because it
would be daunting (and slow) to keep track of a large, constantly-changing
file system if the packets were not written in fixed locations.
The down side is that these packets, with a length of 32 KB (UDF
standard), take up a great deal of overhead space on the disc.
The normal data capacity of a CD-RW disc formatted for writing
in fixed-length packets is about 500 MB. Variable-length packets
save space, because the size of the packet can vary with the size
of the data being written. This is more useful when writing to
a standard CD-R disc, because these are write-once media, and
it is not necessary to track and allocate free space when files
are made invisible.
What is a multisession disc?
A. A session
is a recorded portion of a disc and it's TOC (Table Of Contents).
A multisession CD is made by adding an additional session to a
CD which already has a session on it. You can burn multisession
CDs with linking to previous sessions so that all sessions can
be accessed. If the sessions are not linked, the disc allows only
the last session to be read.
What is incremental writing?
writing is making a disc in multiple writing sessions but the
disc is not closed after each session and cannot be accessed.
The disc is closed when writing to it the last time, at which
point the TOC (Table Of Contents) are written.
What is disc fixation?
A. Disc fixation
is the process of writing the TOC (Table Of Contents).
What are subcodes?
A. There are
eight subcode channels (P, Q, R, S, T, U, V, W). Each channel
can hold 4MB of data. Channel P does not have many applications.
Channel Q includes ISRC (International Standard Recording Code),
position information, and media catalog numbers. Channels R-W
are used for text and graphics. The other channels are generally
How long does it take to record a CD-R and CD-RW disc?
A. The amount
of information being recorded will affect the time required. 650MB
of data takes 74 min at 1x (150KB/sec), 37 min at 2x (300KB/sec),
19 min at 4x (600KB/sec), 13 min at 6x (900KB/sec) and 9.3 min
at 8x (1200KB/sec). Total time needed should include additional
time for writing the TOC (Table Of Contents) which is typically
between 1 to 5 min.
What is the difference between physical and virtual image?
A. The physical
image is an exact copy of the data on the hard drive, the virtual
image is a software pointer to the data. The physical image requires
more HDD space but is more reliable as a rule because of the time
saved when gathering the information during the recording process.
I burned an audio CD but have some pops and problems with it.
What is the cause?
The quality of the audio copies is usually affected by the way
in which the master is read in. First you should make sure you
have a good quality master, a Disk-at-Once recorded master that
has been final fixated is the best way to go. Next be sure to
read in the audio disc at a slower speed than data discs are read
in, usually 2x or 4x at the most, to insure a good quality read.
I have a problem when trying to verify audio CD and video CD?
Because of the way Audio and Video CDs are recorded, CDs containing
Audio or Video tracks cannot be verified.
Can I download MP3s from the Internet and make an audio CD?
Yes. You can download MP3s, write them to a CD. Many popular CD
recording programs will also decode MP3s. It's also possible to
take songs from a CD and convert them to MP3s for use in an MP3
player. See PlayWrite MP3 Pro.
What is the difference between cynanine and phthalocyanine CD-R
dye is the de facto standard. The Orange Book was written based
on the original cyanine dye discs from Taiyo Yuden. Most CD writers
are optimized for cyanine dye. As a result, cyanine discs are
compatible with a wider range of laser powers. Phthalocyanine
dye has performed better than cyanine dye in accelerated age testing,
and may work better in situations that requires higher laser powers,
e.g. higher speed recording. In most situations, the two types
of discs perform essentially the same.
What is BurnProof?
is a Sanyo trademark. It comes the phrase "Buffer Under RuN-Proof."
Recorders using the BurnProof technology can record data past
the end of a recorded point where the recording was stopped due
to the underrun. When used with the
recording software, Sanyo's chipsets that support BurnProof, monitors
the CD-R drive buffer. When it anticipates a buffer underrun,
it puts the recorder into suspend mode, waits for more data from
the source to fill the buffer. Since the address where recording
was suspended is known, the controller can find that exact spot
on the disc when restart. Once found, the recorder will then position
the head on that spot and start recording again. Starting and
stopping in response to a potential buffer underrun results in
a data gap of 40 to 45 milliseconds. This is well within the Orange
Book specification that states that the data gap cannot be more
than 100 milliseconds. During reading, CD error correction will
deal with the data gap, and the user will not notice the existence
of the gap. More testing will tell if this technology is proof
against all forms of buffer underrun.
How do I prepare data for making a CD?
must conform to specific standards that make it possible for a
computer to read them. These standards include the CD-ROM volume
label and the file system standard.
Label This is for the identification of the disc. It is
the equivalent of a book title and is electronically stored on
the CD. The label can anything you wish to identify the CD . The
volume label is limited to eleven characters, using A-Z (upper
case letters only), the numbers 0-9, and the _ (under score).
System Standards You should considered what file system
to use before planning to make a CD. Use a ISO 9660 standard for
CD's that play on all platforms.
If you are
planning to use your CD on both DOS and Mac platforms, your data
must meet ISO 9660 (level 1) requirements. File names meeting
the ISO 9660 (level 1) standard are restricted to the characters
A-Z, 0-9, and the _ (underscore). If you use any other character
or space, it would be converted into an underscore. File names,
(including extensions) may contain 11 characters, the eight dot
three, convention. In the hierarchy of folders or directories,
they cannot go more than eight levels deep.
If you need
long file names, you may create an ISO 9660 (level 3) an ISO 9660
(Joliet Standard) CD-ROM: