How does a CD ROM drive read information from the disk surface?
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How does a CD ROM drive read information from the disk surface?
The CD drive shines a laser at the surface of the CD and can detect the reflective areas and the bumps by the amount of laser light they reflect. The drive converts the reflections into 1s and 0s to read digital data from the disc.
How are CDS manufactured?
It involves creation of a glass master that is placed onto a stamper which is then injected into a mold (shape of a disc) made from polycarbonate substrates. Data is then permanently stamped or “pressed” onto the CD or DVD and the end result is a fully manufactured disc that is playable across multiple platforms.
How do you tell if a CD is a CD-R?
So, a way to tell a CDR vs. a CD is to look at the side that plays. A CDR will have a demarcation line where the laser finished its writing. A real CD will not have this line since it is stamped from a glass-master.
Can you rewrite CD-R discs?
Compact Disc Recordable (CD-R) is a write-once technology. Once an area of the disc has been written to, it cannot be erased. Compact Disc Rewriteable (CD-RW) is a fully rewriteable media, meaning that any spot on a CD-RW disc can be rewritten up to 1,000 times (based on the current standard).
How is information stored in a CD?
Data is stored on the disc as a series of microscopic indentations called “pits”, with the non-indented spaces between them called “lands”. A laser is shone onto the reflective surface of the disc to read the pattern of pits and lands.
What does a CD manufacturer do?
Compact disc manufacturing is the process by which commercial compact discs (CDs) are replicated in mass quantities using a master version created from a source recording. This may be either in audio form (CD-Audio) or data form (CD-ROM). This process is used in the mastering of read-only compact discs.
What material are CDs made of?
polycarbonate plastic
A standard CD is 120 mm (4.75 inch) in diameter and 1.2 mm (0.05 inch) thick. It is composed of a clear polycarbonate plastic substrate, a reflective metallic layer, and a clear protective coating of acrylic plastic.
How can you tell if CDs are fake?
How to tell if a CD or DVD is fake
- Look at the bottom of the disc. One of the most common and easiest ways is to look at the bottom of the disc.
- Look at the label.
- What the CD or DVD case looks like.
- Software marked as OEM or NFR.
- Price too good to be true.
Can you reuse a CD-R?
No, you cannot erase anything on a CD-R. Whatever you put on one it’s on there permanently. For erasing, you can use CD-RW disks.