Find an image, description, examples and advantages for each of the following:
1. Magnetic Disk
2. Optical Disk
3. Flash Memory
4. Magneto-optical Disk
Magnetic disk
Magnetic disc use magnetic particles that coated the surface to store items, data, instruction, and information. Like tape, it is magnetically recorded and can be re-recorded over and over. Disks are rotating platters with a mechanical arm that moves a read/write head between the outer and inner edges of the platter's surface. It can take as long as one second to find a location on a floppy disk to as little as a couple of milliseconds on a fast hard disk.Example:
Fixed hard disk
Zip removable disk
Floppy disk
Pocketzip
Advantage:
1. The advantages magnetic disk include the ability to write/record and read data very rapidly. 2. Data that is no longer needed can be erased to make space available for new data.
3. The number of images that can be stored on a magnetic disk depends on the numerical size of the images and the disk capacity.
4. The capacity (Megabytes) of a specific disk size is determined by how small the individual bit areas can be made.
Optical disk
An optical disk is a type of storage media that consist a flat, round, portable disk made of metal, plastic, and laquer that is written and read by laser. It is primarily store software, data, digital photo, movies, and music. Some of it are read only, and read and write. The optical disk includes a stiffening layer having two spaced-apart surfaces, the stiffening layer having a specific stiffness selected to be greater than 1*108 inches and being positioned at the center of the thickness of the optical disk. The optical disk further includes first and second recording layers, each recording layer being formed over opposite surfaces of the stiffening layer, and first and second substrates being formed over the first and second recording layers, respectively.
Example
CD-ROM
DVD-R/CD-RW.
Advantage:
1. Reliable for long term storage.
2. The high capacity and low cost per unit of data stored make optical media an effective storage solution.
Flash memory
Flash memory card are a type of solid-state media that means they consist entirely of electronic components and contain no moving parts. Flash memory is non-volatile memory computer that can be electrically erased and reprogrammed. It is a technology that is primarily used in memory card and USB flash drives for general storage and transfer of data between computers and other digital products.
Example
USB Flash Drive
Memory Card
Advantage
1. Flash memory has no moving parts and can be more durable.
2. It can use less power.
Magneto optical disk
A type of disk that combines magnetic disk technologies and CD-ROM technologies. A magneto-optical drive is a kind of optical disc drive capable of writing and rewriting data upon a magneto-optical disc. These drives use a hybrid of magnetic and optical technologies, employing laser to read data on the disk, while additionally needing magnetic field to write data. An MO disk drive is so designed that an inserted disk will be exposed to a magnet on the label side and to the light (laser beam) on the opposite side. The disks, which come in 3.5in and 5.25in formats, have a special alloy layer that has the property of reflecting laser light at slightly different angles depending on which way it's magnetized, and data can be stored on it as north and south magnetic spots, just like on a hard disk.
Example
WORM
Advantage
1. Induced super resolution' (MSR), heat distribution and magnetism within the laser beam enable MO drives to read data that is smaller than the beam spot size, enhancing storage density
2. Magneto-optical disks, such as the rewritable optical disk and the recordable disk used with the Mini Disc player, have a special layer, as of barium ferrite, that can be magnetically polarized by a recording head when heated with a laser. Data or sound may be recorded to and erased from any portion of a magneto-optical disk multiple times.
