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A CD writer burns little holes in an aluminum disk (between 2 plastic plates).
This causes little bumps to appear on the disc.
A CD drive can read the data back out using a laser that reflects on that surface.
in a bump the laser will reflect in a different angle then when there isn't a bump.
the CD drive detects this and reads a '1' if the laser is not reflected (no bump) and a '0' if the laser is reflected (hits a bump).
This method of storing data contains a lot of errors, bumps that are read wrong.
That's why a CD contains 2/3 fault checks on the actual data.
This means that on a CD you can actually write 2.1 GB of data, but only 700mb is the data you store because 1.4gb is used to repair the mistakes in reading.
Wiki User
∙ 13y ago
Wiki User
∙ 14y ago"Here's how the CD-ROM works, in a nutshell (I'm not going to go into the gory details of how the laser beams are manipulated within the drive because that can get complicated--there are in fact several slightly different ways that the internals work): A beam of light energy is emitted from an infrared laser diode and aimed toward a reflecting mirror. The mirror is part of the head assembly, which moves linearly along the surface of the disk. The light reflects off the mirror and through a focusing lens, and shines onto a specific point on the disk. A certain amount of light is reflected back from the disk. The amount of light reflected depends on which part of the disk the beam strikes: each position on the disk is encoded as a one or a zero based on the presence or absence of "pits" in the surface of the disk. This is discussed in more detail in the section on CD-ROM media. A series of collectors, mirrors and lenses accumulates and focuses the reflected light from the surface of the disk and sends it toward a photodetector. The photodetector transforms the light energy into electrical energy. The strength of the signal is dependent on how much light was reflected from the disk. Most of these components are fixed in place; only the head assembly containing the mirror and read lens moves. This makes for a relatively simplified design. CD-ROMs are of course single-sided media, and the drive therefore has only one "head" to go with this single data surface." Source(s): http://www.pcguide.com/ref/cd/const.htm
Wiki User
∙ 14y agoCD data is stored as a series of tiny indentations known as "pits", encoded in a spiral track molded into the top of the polycarbonate layer.
Wiki User
∙ 15y agoBumps and holes are etched onto a compact disk, with the bumps meaning binary digit "0" and the holes meaning "1."
Wiki User
∙ 12y agoin the "holes" that are so small you can't see them.
Wiki User
∙ 14y ago700 Mbytes.
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How do cds work?
Compact discs (CD) are read from the inside out ... About an inch of the The inner radius of a compact discs is used for clamping and is used to identify the manufacturer ... These parts of the compact discs can not be copied with out side data and can not be damage with the exception of snapping the whole compact discs in half ... A compact disc that constants music has the inner band of data which is called the lead-in hold the table of contents for the compact disc ... The table of content lets the compact discs know how to navigate around the disc ... Music on a compact disc start just outside the lead-in ... The larger the music track the grater the width is on the compact disc ... A compact disc can hold upwards to 80 minutes of music ... You can tell where the music is on a compact disc by the barker shades on the compact disc ... when the compact disc is not full you can tell by the lightness on the compact disc ... To tell where the tracks are on a music compact disc there are very thin faint circles that separate the ... Unlike a vinyl record which is read by a needle which lies within the grooves a compact disc is read by a laser which allows it to be read with only the laser beam "touching" the data ... The laser beam enters the compact disc on the play side and travels through the compact discs clear plastic layer which picks up information from the data layer then bounces off the reflective coating on the back side of the data layer ... The reflected laser beam then travels back through the clear plastic layer out of the compact disc and into the compact disc player's detector ... The detector then helps the compact disc player convert the information carried by the laser into sound ...
What do the letters inCD-ROM stand for?
Compact Disc-Read Only Memory
What is the full form of CDS?
The full form of CDS is the Compact Disc - Read-Only Memory or Compact Disc - Digital Audio. It is a digital optical disc data storage format.
What does the abbreviation CD ROM stand for?
Compact Disc CD is Compact Disc. ROM is Read-Only Memory. This is a manufactured CD that can only be read, not written.
What is the use of the CD-R?
CD-R stands for Compact Disc-Recordable is a variation of the Compact Disc. It is generally used as just like a Compact Disc is used. It is a Write Once Read Memory (WORM), as once written, cannot be erased after the writing of data.
What is the uses of CD-R?
CD-R stands for Compact Disc-Recordable is a variation of the Compact Disc. It is generally used as just like a Compact Disc is used. It is a Write Once Read Memory (WORM), as once written, cannot be erased after the writing of data.
What does CD-RW stand for?
Compact Disc Re-WritableIt describes a Compact Disc that contain materials within it capable not only of recording data burned onto it by a laser but also (with the application of a stronger laser) having that information erased so that the disc can be rewritten. CD-RW discs can usually only be used properly in optical drives that specify that they can read (and usually write) that type of disc.
What are some similarties between floppy disks and compact disks?
They both hold data They are both disc shaped A drive is used to read or write to them The primary difference is the way they hold data. The data on a floppy disc is carried and read magnetically. The data on a CD is recorded and read optically with a laser.
What does CD ROM mean?
CD ROM Means compact disc read-only memory Compact Disc
How do CD-ROMs read information?
Compact Disc-Read Only Memory (CD-ROM) drives use laser beams to read information on a rotating synthetic disk.
How do CD players work?
c.d players have three major components. The laser reads the bumps on a c.d from the inner part to the outer part. The disk motor drive spins the disk between 200-500 r.p.m While the c.d is spinning, the tracking motor moves back and forth across the c.d from the edge to the inside.
What does the compact disc do?
A compact disc, first marketed in 1983, is a sound carrier that is played by a laser beam that reads the code in the disc. A compact disc player is a machine that spins the disc, shines a laser on it, and sends the resulting electrical signal to an amplifer, which sends it to speakers.
