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Unformatted text preview: cing patterns of on and off
reflections that are converted into electronic signals of binary Is and Os by a sensor.
Magneto-optical disks are today available in various sizes and storage capacities. The
ones having 5'/4-inch and 3/2-inch diameter have storage capacities in excess of 1 GB.
However, the access speed of magneto-optical disk drives is slower than hard-disk drives.
The access time for magneto-optical disk drives is about 30 milliseconds which is almost
as fast as the access speed of slower hard-disk drives. Moreover, magneto-optical disk
drives are more expensive and less feliable than magnetic disk drives. Due to these
reasons, magneto-optical disks are not yet as popular as magnetic disks or optical disks.
But as magneto-optical disk technology matures to offer reliable and cost-effective
rewritable storage media, it eventually may dominate the secondary storage market in the
Magneto-optical disks are ideal for multimedia applications that require large storage
capacity. They are also used for applications that require large volumes of storage with
relatively little update activity, and for applications that require a reusable, portable and
durable secondary storage device.
MASS STORAGE DEVICES
Mass storage devices are storage systems that have storage capacity of several trillions of
bytes of data. Researchers are constantly trying to improve the secondary storage media discussed
above by increasing their capacity, performance, and reliability. However, any physical
storage media has a limit to its capacity and performance. When it gets harder to make
further improvements in the physical storage media and its drive, researchers normally
look for other methods for improvement. Mass storage devices are a result of such
improvements which researchers have resorted to for larger capacity secondary storage
devices. The idea is to use multiple units of the storage media being used (such as
multiple disks, multiple tapes, multiple CD-ROMs, etc.) as a single secondary storage
device. Based on this idea, the three types of commonly used mass storage devices are:
1. Disk array, which uses a set of magnetic...
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- Spring '14