Storage Devices

1. STORAGE DEVICES

2. DEFINITION - WHAT DOES ‘STORAGE
DEVICE’ MEAN?
A storage device is any computing hardware that is used for storing,
porting and extracting data files and objects. It can hold and store
information both temporarily and permanently, and can be internal or
external to a computer, server or any similar computing device.
A storage device may also be known as a storage medium or storage
media.

3. EXPLANATION ‘STORAGE DEVICE’.
Storage devices are one of the core components of any computing
device. They store virtually all the data and applications on a
computer, except hardware firmware. They are available in different
form factors depending on the type of underlying device. For example,
a standard computer has multiple storage devices including RAM,
cache, a hard disk, an optical disk drive and externally connected
USB drives.

4. These usually have large
storage capacity, and they
store data permanently. They
can be both internal and
external to the computer, and
they include the hard disk,
compact disk drive and USB
storage device.
Generally smaller in size, are
designed to hold data
temporarily and are internal to
the computer. They have the
fastest data access speed,
and include RAM and cache
memory.
THERE ARE TWO DIFFERENT TYPES OF
STORAGE DEVICES:
Primary storage devices Secondary storage devices

5. THESE ARE SOME EXAMPLES OF STORAGE
DEVICES

6. PRIMARY STORAGE DEVICES

7. RANDOM ACCESS MEMORY ( RAM )

8. Random-access memory (RAM) is a form of computer data storage which stores
frequently used program instructions to increase the general speed of a system. A
random-access memory device allows data items to be read or written in almost the
same amount of time irrespective of the physical location of data inside the memory. In
contrast, with other direct-access data storage media such as hard disks, cd-rws, dvd-
rws and the older drum memory, the time required to read and write data items varies
significantly depending on their physical locations on the recording medium, due to
mechanical limitations such as media rotation speeds and arm movement.
RAM contains multiplexing and demultiplexing circuitry, to connect the data lines to the
addressed storage for reading or writing the entry. Usually more than one bit of
storage is accessed by the same address, and RAM devices often have multiple data
lines and are said to be '8-bit' or '16-bit' etc. Devices.
In today's technology, random-access memory takes the form of integrated circuits.
RAM is normally associated with volatile types of memory (such as DRAM memory
modules), where stored information is lost if power is removed, although non-volatile
RAM has also been developed.[1] other types of non-volatile memories exist that allow
random access for read operations, but either do not allow write operations or have
other kinds of limitations on them. These include most types of ROM and a type of
flash memory called nor-flash.
Integrated-circuit RAM chips came into the market in the early 1970s, with the first
commercially available DRAM chip, the intel 1103, introduced in october 1970.[2]

9. SECONDARY STORAGE DEVICES

10. HARD DISK DRIVE (HDD)

11. PARTS OF HDD
ROTATION SPEED OF PLATTER IS AROUND 7200rpm

12. A hard disk drive (HDD), hard disk, hard drive or fixed disk[b] is a data storage device that uses magnetic
storage to store and retrieve digital information using one or more rigid rapidly rotating disks (platters) coated
with magnetic material. The platters are paired with magnetic heads, usually arranged on a moving actuator
arm, which read and write data to the platter surfaces.[2] data is accessed in a random-access manner, meaning
that individual blocks of data can be stored or retrieved in any order and not only sequentially. HDDs are a type
of non-volatile storage, retaining stored data even when powered off.[3][4][5]
introduced by IBM in 1956,[6HDDs became the dominant secondary storage device for general-purpose
computers by the early 1960s. Continuously improved, hdds have maintained this position into the modern era
of servers and personal computers. More than 200 companies have produced HDDs historically, though after
extensive industry consolidation most current units are manufactured by seagate, toshiba, and western digital.
As of 2016[update], HDD production (in bytes per year) is growing, although unit shipments and sales revenues
are declining. The primary competing technology for secondary storage is flash memory in the form of solid-
state drives (SSDs), which have higher data-transfer rates, higher areal storage density, better reliability,[7] and
much lower latency and access times.[8][9][10][11] while SDDs have higher cost per bit, SSDs are replacing HDDs
where speed, power consumption, small size, and durability are important.[10][11]
the primary characteristics of an HDD are its capacity and performance. Capacity is specified in unit prefixes
corresponding to powers of 1000: a 1-terabyte (TB) drive has a capacity of 1,000 gigabytes (GB; where 1
gigabyte = 1 billion bytes). Typically, some of an HDD's capacity is unavailable to the user because it is used by
the file system and the computer operating system, and possibly inbuilt redundancy for error correction and
recovery. Performance is specified by the time required to move the heads to a track or cylinder (average
access time) plus the time it takes for the desired sector to move under the head (average latency, which is a
function of the physical rotational speed in revolutions per minute), and finally the speed at which the data is
transmitted (data rate).
The two most common form factors for modern HDDs are 3.5-inch, for desktop computers, and 2.5-inch,
primarily for laptops. HDDs are connected to systems by standard interface cables such as PATA (parallel ATA),
SATA (serial ATA), USB or SAS (serial attached SCSI) cables.

13. USB DRIVE (PEN DRIVE)

14. PEN DRIVE
Introduction
pen drive also referred as USB flash drive is a portable device which allows user to transfer data
(text, images, videos etc.) To and from computer quickly. Users can easily read and write the data
on the pen drive by plugging it into the USB port on the computer. Pen drives are quite compact
and can fit easily into the pocket; they run without battery and draw power from the USB
connection itself. Both floppy disks and CDs are now being gradually replaced by pen drive as a
preferred means of data storage. Its because latter offers mass data transfer and storage capability
and at a much faster rate.
Storage capacity of the pen drive can vary from few megabytes to over 100 GB. Nowadays even
external hard drives are available in the market with huge storage capacity, which like pen drive
can be connected to a USB port on the computer.
Architecture
pen drive consist of an electronic circuit board and a USB connector connects the drive to the
computer. Pen drive also known as a flash memory is an example of NAND style storage device. It
is a memory chip which holds the data. Data output is controlled by crystal oscillator which
produces 12 MHz clock signal in the device.
Most pen drives are covered with plastic, metal or rubber casing for insulation.
Advantages
pen drives are robust and scratch free thus ensuring maximum security for your data as compared
to other traditional means of data storage. Many available PC software suites permit the launch of
an operating system from the bootable pen drive. Moreover companies selling pen drives
nowadays also couple it with other devices like MP3 music player, lad's or Swiss knife etc.

15. COMPACT DISK ( CD )

16. Compact disc (CD) is a digital optical disc data storage format released in 1982 and co-
developed by philips and sony. The format was originally developed to store and play
only sound recordings but was later adapted for storage of data (CD-ROM). Several
other formats were further derived from these, including write-once audio and data
storage (CD-R), rewritable media (CD-RW), video compact disc (VCD), super video
compact disc (SVCD), photo CD, picture CD, cd-i, and enhanced music CD. The first
commercially available audio CD player, the sony CDP-101, was released october 1982 in
japan.
Standard cds have a diameter of 120 millimetres (4.7 in) and can hold up to about 80
minutes of uncompressed audio or about 700 MB of data. The mini CD has various
diameters ranging from 60 to 80 millimetres (2.4 to 3.1 in); they are sometimes used for
CD singles, storing up to 24 minutes of audio, or delivering device drivers.
At the time of the technology's introduction in 1982, a CD could store much more data
than a personal computer hard drive, which would typically hold 10 MB. By 2010, hard
drives commonly offered as much storage space as a thousand cds, while their prices
had plummeted to commodity level. In 2004, worldwide sales of audio cds, cd-roms and
cd-rs reached about 30 billion discs. By 2007, 200 billion cds had been sold worldwide.[1]
from the early 2010s cds were increasingly being replaced by other forms of digital
storage and distribution, with the result that audio CD sales rates in the U.S. Have
dropped about 50% from their peak; however, they remain one of the primary
distribution methods for the music industry.[2] in 2014, revenues from digital music
services matched those from physical format sales for the first time.

17. MEMORY CARD

18. A memory card or flash memory card is a solid-state electronic flash memory data storage devices used
with digital cameras, handheld and laptop computers, telephones, music players, video game consoles,
and other electronics. They offer high re-record ability, power-free storage, small form factor, and
rugged environmental specifications. There are also non-solid state memory cards that do not use flash
memory, and there are different types of flash memory.
Flash cards have been suggested as a possible replacement for the floppy disk, although USB flash
memory drives, which work on almost any computer with a USB port, have been filling this role instead.
There are many different types of memory cards and jobs they are used for. Some common places
include in digital cameras, in game consoles, in cell phones, and in industrial applications. Pc card
(pcmcia) were among first commercial memory card formats (type I cards) to come out in the 1990s, but
are now only mainly used in industrial applications and for i/o jobs (using types i/ii/iii), as a connection
standard for devices (such as a modem). Also in 1990s, a number of memory card formats smaller than
pc card came out, including CompactFlash, smart media, and miniature card. In other areas, tiny
embedded memory cards (Sid) were used in cell phones, game consoles started using proprietary
memory card formats, and things like pad's and digital music players started using removable memory
cards.
From the late 1990s into the early 2000s a host of new formats appeared, including SD/mmc, memory
stick, XD-picture card, and host of variants and smaller cards. The desire for ultra-small cards for cell-
phones, pdas, and compact digital cameras drove a trend toward smaller cards that left the previous
generation of "compact" cards looking big. In digital cameras smart media and CompactFlash had been
very successful, in 2001 SM alone captured 50% of the digital camera market and cf had a strangle hold
on professional digital cameras. By 2005 however, sd/mmc had nearly taken over smart media's spot,
though not to the same level and with stiff competition coming from memory stick variants, xd, as well
as compactflash. In industrial fields, even the venerable pc card (pcmcia) memory cards still manage to
maintain a niche, while in cell-phones and pdas, the memory card market is highly fragmented.
Nowadays, many new pcs and pdas have built-in slots for a variety of memory cards; compactflash, sd,
etc.