Magnetic Disk
Image:
Description:On magnetic disks, data is encoded as microscopic magnetized needles on the disk's surface.
You can record and erase data on a magnetic disk any number of times, just as you can with a cassette tape.
On magnetic disks, data is encoded as microscopic magnetized needles on the disk's surface.
You can record and erase data on a magnetic disk any number of times, just as you can with a cassette tape.
You can record and erase data on a magnetic disk any number of times, just as you can with a cassette tape.
Examples:
Magnetic disks come in a number of different forms:
Floppy disk :
A typical 5¼-inch floppy disk can hold 360K or 1.2MB (megabytes). 3½-inch floppies normally store 720K, 1.2MB or 1.44MB of data.
Hard disk :
Hard disks can store anywhere from 20MB to more than 200GB. Hard disks are also from 10 to 100 times faster than floppy disks.
Removable cartridge :
Removable cartridges are hard disks encased in a metal or plastic cartridge , so you can remove them just like a floppy disk. Removable cartridges are very fast, though usually not as fast as fixed hard disks.
Magnetic disks come in a number of different forms:
Floppy disk :
A typical 5¼-inch floppy disk can hold 360K or 1.2MB (megabytes). 3½-inch floppies normally store 720K, 1.2MB or 1.44MB of data.
Hard disk :
Hard disks can store anywhere from 20MB to more than 200GB. Hard disks are also from 10 to 100 times faster than floppy disks.
Removable cartridge :
Removable cartridges are hard disks encased in a metal or plastic cartridge , so you can remove them just like a floppy disk. Removable cartridges are very fast, though usually not as fast as fixed hard disks.
Advantages:
It has a high storage capacity. It is very reliable. It gives direct access to data.
A drive spins the disk very quickly underneath a read/write head, which does what its name says. It reads data from a disk and writes data to a disk.
Optical Disk
Image:
Image:
Description:
Optical disks record data by burning microscopic holes in the surface of the disk with a laser.
To read the disk, another laser beam shines on the disk and detects the holes by changes in the reflection pattern.
Examples:
Optical disks come in three basic forms:
CD-ROM :
Most optical disks are read-only. When you purchase them, they are already filled with data. You can read the data from a CD-ROM, but you cannot modify, delete, or write new data.
WORM :
Stands for write-once, read-many. WORM disks can be written on once and then read any number of times; however, you need a special WORM disk drive to write data onto a WORM disk.
Erasable optical (EO ):
EO disks can be read to, written to, and erased just like magnetic disks.
Optical disks record data by burning microscopic holes in the surface of the disk with a laser.
To read the disk, another laser beam shines on the disk and detects the holes by changes in the reflection pattern.
Examples:
Optical disks come in three basic forms:
CD-ROM :
Most optical disks are read-only. When you purchase them, they are already filled with data. You can read the data from a CD-ROM, but you cannot modify, delete, or write new data.
WORM :
Stands for write-once, read-many. WORM disks can be written on once and then read any number of times; however, you need a special WORM disk drive to write data onto a WORM disk.
Erasable optical (EO ):
EO disks can be read to, written to, and erased just like magnetic disks.
Advantages:
Physical:
An optical disk is much sturdier than tape or a floppy disk. It is physically harder to break or melt or warp.
Delicacy:
It is not sensitive to being touched, though it can get too dirty or scratched to be read. It can be cleaned!
Magnetic:
It is entirely unaffected by magnetic fields.
Capacity:
Optical disks hold much more data than floppy disks.
Others:
The non-data side of the disk can have a pretty label.
For software providers, an optical disk is a great way to store the software and data that they want to distribute or sell.
Flash Memory
Image:
Image:
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. Flash memory costs far less than byte-programmable EEPROM and therefore has become the dominant technology wherever a significant amount of non-volatile, solid-state storage is needed. Example applications include It has also gained popularity in the game console market, where it is often used instead of EEPROMs or battery-powered SRAM for game save data.
Examples:
Flash memory is very useful in a variety of applications including:
Computer BIOS
PDAs (personal digital assistants)
laptop computers
digital audio players
digital cameras
mobile phones
Memory sticks
PCMCIA memory cards
MP3 players
Modems
Video game cards
Digital cellular phones
Digital cameras
Advantages:
Flash memory can erase its data in entire blocks, making it a preferable technology for applications that require frequent updating of large amounts of data as in the case of a memory stick.
Flash memory costs far less than byte-programmable EEPROM
It is non-volatile, no power is required to maintain the information stored in the chip.
It offers fast read access and better kinetic shock resistance than hard disk.
In memory, it is enormously durable, than can withstand extreme of temperature,intense pressure and immersion in water.
Magneto-optical Disk
Image:
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. Flash memory costs far less than byte-programmable EEPROM and therefore has become the dominant technology wherever a significant amount of non-volatile, solid-state storage is needed. Example applications include It has also gained popularity in the game console market, where it is often used instead of EEPROMs or battery-powered SRAM for game save data.
Examples:
Flash memory is very useful in a variety of applications including:
Computer BIOS
PDAs (personal digital assistants)
laptop computers
digital audio players
digital cameras
mobile phones
Memory sticks
PCMCIA memory cards
MP3 players
Modems
Video game cards
Digital cellular phones
Digital cameras
Advantages:
Flash memory can erase its data in entire blocks, making it a preferable technology for applications that require frequent updating of large amounts of data as in the case of a memory stick.
Flash memory costs far less than byte-programmable EEPROM
It is non-volatile, no power is required to maintain the information stored in the chip.
It offers fast read access and better kinetic shock resistance than hard disk.
In memory, it is enormously durable, than can withstand extreme of temperature,intense pressure and immersion in water.
Magneto-optical Disk
Image:
Description:
A magneto-optical drive is a kind of optical disc drive capable of writing and rewriting data upon a magneto-optical disc.
Both 130 mm and 90 mm form factors exist.
The technology was introduced at the end of the 1980s.
Although optical, they appear as hard disk drives to the operating system and do not require a special filesystem (they can be formatted as FAT, HPFS, NTFS, etc.).
A magneto-optical drive is a kind of optical disc drive capable of writing and rewriting data upon a magneto-optical disc.
Both 130 mm and 90 mm form factors exist.
The technology was introduced at the end of the 1980s.
Although optical, they appear as hard disk drives to the operating system and do not require a special filesystem (they can be formatted as FAT, HPFS, NTFS, etc.).
Examples:
Diskette drive
Rewritable OD 230MB Data Type Cartridge
Advantages:
CD-MO is read by a laser beam, which makes it more reliable than a hard disk or a floppy disk.
However, a strong magnetic field can corrupt the stored data.
Although optical, they appear as hard disk drives to the operating system but need no special filesystem.
1 comment:
I like the feature of DVD-Ram which includes in a high storage capacity, reliable and its gives us access of data. It reads data from a disk and writes data to a disk.
===================================
Ritika
look4ward
Post a Comment