The advent of the CD technology has a resulted in a drastic fall in the use of floppy disks. This is because a floppy disk can hold only 1.44 MB of data while a single CD can hold about 650 MB of data which is equivalent to approximately 25,000 of text pages. Also the cost incurred to make a CD is less then a dollar. Most of the software today is available on a CD-ROM.
A CD-ROM (Compact Disc Read-Only Memory) drive is a device that reads information from a CD-ROM. The CD-ROM drive makes use of a laser to read data or information from the CD-ROM. Earlier CD-ROM drives used a caddy. The disc had to be inserted into the caddy, and the caddy inserted into the drive. Today, CD-ROM drives do not have any caddy. The disc is placed into a tray. Digital data are carved into the CD-ROM as pits and lands. The pits are known as low spots while lands are called as high spots. As the laser shines into the moving pits and lands, a sensor detects a change in reflection when it encounters a transition from pit to land or land to pit. Each transition is a 1. The lack of transitions is 0s. There is only one laser in a drive. Most of the PCs available in the market today have a CD-ROM drive.
This buying guide focuses on the following aspects of CD-ROM drives:
Types of CD-ROM drives
Key features in a CD-ROM drive
1) Types of CD-ROM drives
A CD-ROM drive could be internal or external.
a) Internal CD-ROM drive
Internal CD-ROM drives are those CD-ROM drives that are fitted in a bay just below the diskette drive. Internal CD-ROM drives make use of the computer's power supply instead of their own. Internal CD-ROM drives have an Integrated Device Electronics (IDE) interface instead of the Small Computer System Interface (SCSI) because of which they are cost-effective. A major disadvantage of internal CD-ROM drives is that they cannot be shifted from one PC to another as a result of which two computers cannot share the same drive. ASUS CD S520B and MSI C52 are examples of internal hard drives. Click here to select from a wide array of other internal CD-ROM drives. .
