STORAGE AND MEMORY DEVICES
Made by: Muhammad Hassaan Arif
STORAGE DEVICES
A data storage device is a device for recording (storing) information (data).
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Made by: Muhammad Hassaan Arif
MAGNETIC TAPE
MAGNETIC DISK
Made by: Muhammad Hassaan Arif
A plastic tape coated with iron oxide for use in magnetic recording.
Magnetic tape is a serial access medium, similar to an audio cassette, and so data cannot be quickly located.
However large amounts of information can be stored within magnetic tape. This characteristic has prompted its use in the regular backing up of hard disks.
MAGNETIC TAPE
Made by: Muhammad Hassaan Arif
The primary computer storage device. 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.
MAGNETIC DISK
Made by: Muhammad Hassaan Arif
Common types are:– Hard disks– Floppy disks– Zip disks
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.
MAGNETIC DISK
Made by: Muhammad Hassaan Arif
MEMORY VS STORAGE
HARD DRIVE- STORAGERAM- MEMORY(RANDOM ACCESS MEMORY)
Made by: Muhammad Hassaan Arif
RAM- MEMORY(RANDOM ACCESS MEMORY)
Memory is a temporary workplace where the computer transfers the contents of a file while it is being used.
Random Access Memory (RAM) is a computer storage location that allows information to be stored and accessed quickly from random locations.
Made by: Muhammad Hassaan Arif
Storage, also known as mass media, refers to the various media on which computer system can store data.
Hard drive is one of them. There are some features such as:
High capacity disk. Most common media of storage. Use one or more metal magnetic disks.
HARD DRIVE - STORAGE
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CATEGORIES
The type of operations they perform.
The method they use to access the information.
The technology they use. Their capacity and speed.
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SEQUENTIALACCESS STORAGE
VS
RANDOM ACCESS STORAGE
Made by: Muhammad Hassaan Arif
SEQUENTIAL ACCESS STORAGE
Storage devices that read and write data in a serial fashion.
Made by: Muhammad Hassaan Arif
RANDOM ACCESS STORAGE
Storage devices that read and write data without going through a sequence of locations.
Made by: Muhammad Hassaan Arif
STORAGE TECHNOLOGIES
Made by: Muhammad Hassaan Arif
MAGNETIC STORAGE
OPTICAL STORAGE CD/DVD DRIVE
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MAGNETIC STORAGE
Storage devices use disks or tapes that are coated with magnetically sensitive material.
Made by: Muhammad Hassaan Arif
OPTICAL STORAGE CD/DVD DRIVE
Storage devices that use laser beams to read patterns etched into plastic disks.
Made by: Muhammad Hassaan Arif
MAGNETIC DISK STORAGE
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Made by: Muhammad Hassaan Arif
MAGNETIC DISK STORAGE
A disk is formatted; it is divided into tracks and sectors, and a file allocation table (FAT) is created.
Track – circular band
Sector – pie shaped section
Cluster – two or more adjacent sectors
FAT – keeps tracks of specific locations of files
Made by: Muhammad Hassaan Arif
Made by: Muhammad Hassaan Arif
STORAGE CAPACITY &
SPEED
Made by: Muhammad Hassaan Arif
STORAGE CAPACITY &
SPEED
Floppy DiskCapacity – 720 KB to 1.44 MB
Hard DriveCapacity – up to 1000 GB ( 1 TB)
CD ROM/DVDCapacity – CD ROM 650 MB – DVD 17 GB
Made by: Muhammad Hassaan Arif
FLOPPY & ZIP DISKS &DRIVES
Made by: Muhammad Hassaan Arif
3.5’’ – FLOPPY DISKS & DRIVE
High – density floppy disks that are commonly used today store 1.44MB and 2.8MB of data.
A disk or diskette is a portable storage medium.
Low capacity removable disk.
Not widely used today.Made by: Muhammad Hassaan Arif
ZIP DISKS
Zip disks store up to 750 Mb of data and are not downwardly compatible with floppy disks.
Made by: Muhammad Hassaan Arif
CD-ROM DISCS & DRIVES
CD-ROM stand for compact disc read only memory.
CD-ROM drives can not write data to disc.
They are capable of storing 650 MB of data.
They are used for operating system; large application programs.
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Made by: Muhammad Hassaan Arif
CD-R & CD-RW & RECORDERS
CD-R Discs can only
be written to “once”
CD-R drives are capable of reading and writing data.
CD-RW Discs are erasable
Discs can be written to many times
CD-RW drives are capable of reading, writing and erasing data
Made by: Muhammad Hassaan Arif
DVD stand for Digital Video Disc.
DVD technology is similar to CD-ROM technology.
DVDs are capable of storage up to 17GB of data.
DVD-R and DVD-RW drives have the ability to read and write data.
DVD-ROM DISCS & DRIVES
Made by: Muhammad Hassaan Arif
SOLID STATE STORAGE DEVICES
Solid state storage devices use nonvolatile memory chips to retain data.
They do not have moving parts.
They are small, lightweight, reliable and portable.
Made by: Muhammad Hassaan Arif
Made by: Muhammad Hassaan Arif