STORAGE DISKS
Magnetic Disk
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Description:
Magnetic disk uses different patterns of magnetization in a magnetizable material to store data and is a form of non-volatile memory. The information is accessed using one or more read/write heads.
Examples:
Hard disk, digital tape, floppy disk
Advantages:
-High storage capacity
-Reliable
-Gives direct access to data
Optical Disk
Images:
Magnetic disk uses different patterns of magnetization in a magnetizable material to store data and is a form of non-volatile memory. The information is accessed using one or more read/write heads.
Examples:
Hard disk, digital tape, floppy disk
Advantages:
-High storage capacity
-Reliable
-Gives direct access to data
Optical Disk
Images:
Description:
Optical disk is a flat, circular disc (usually polycarbonate) wherein data are stored in the pits (or bumps) in its flat surface; sequentially on the continuous, spiral track extending from the innermost track to the outermost track, covering the entire disc surface. The data are accessed in the disc when a special material (often aluminium) is illuminated with a laser diode. The pits distort the reflected laser light. So most optical disks characteristically have an iridescent appearance created by the grooves of the reflective layer.
Examples:
Compact disk(CD), DVD, blue-ray disk.
Advantages:
-Much sturdier than tape or a floppy disk.
-Physically harder to break or melt or warp.
-Not sensitive to being touched, though it can get too dirty or scratched to be read. It can be cleaned.
-Entirely unaffected by magnetic fields.
-Hold much more data than floppy disk.
Flash Memory
Images:
Optical disk is a flat, circular disc (usually polycarbonate) wherein data are stored in the pits (or bumps) in its flat surface; sequentially on the continuous, spiral track extending from the innermost track to the outermost track, covering the entire disc surface. The data are accessed in the disc when a special material (often aluminium) is illuminated with a laser diode. The pits distort the reflected laser light. So most optical disks characteristically have an iridescent appearance created by the grooves of the reflective layer.
Examples:
Compact disk(CD), DVD, blue-ray disk.
Advantages:
-Much sturdier than tape or a floppy disk.
-Physically harder to break or melt or warp.
-Not sensitive to being touched, though it can get too dirty or scratched to be read. It can be cleaned.
-Entirely unaffected by magnetic fields.
-Hold much more data than floppy disk.
Flash Memory
Images:
Description:
Flash memory is non-volatile computer memory that can be electrically erased and reprogrammed. It is a technology that is primarily used in memory cards and USB flash drives for general storage and transfer of data between computers and other digital products. It is a specific type of EEPROM (Electrically Erasable Programmable Read-Only Memory) that is erased and programmed in large blocks; in early flash the entire chip had to be erased at once.
Examples:
Memory stick(MS), smart media(SM), compact flash(CF), security digital(SD).
Advantages:
-Does not have the mechanical limitations and latencies of hard drives.
-Low power consumption
-No moving parts
-Nearly instantaneous access times
Magneto-optical Disk
Images:
Description:
Magneto-optical disks are a hybrid storage medium. In reading, spots with different directions of magnetization give different polarization in the reflected light of a low-power laser beam. Magneto-optical disks need lasers to write data to the discs and magnetic heads to read data from the discs.
Examples:
six LMR1300 5.25" Magneto Optical disks, HP Magneto-Optical Disk Write-once 2.6 GB 92290F, Sony 5.2GB Magneto-Optical MO Disk Unit RMO-S551
Advantages:
-Data authenticity and integrity
-Long-term data retention
-High capacity and scalability
-Rapid information access.
Magneto-optical disks are a hybrid storage medium. In reading, spots with different directions of magnetization give different polarization in the reflected light of a low-power laser beam. Magneto-optical disks need lasers to write data to the discs and magnetic heads to read data from the discs.
Examples:
six LMR1300 5.25" Magneto Optical disks, HP Magneto-Optical Disk Write-once 2.6 GB 92290F, Sony 5.2GB Magneto-Optical MO Disk Unit RMO-S551
Advantages:
-Data authenticity and integrity
-Long-term data retention
-High capacity and scalability
-Rapid information access.
