8th grade Unit 1 : Storage devices and data units of measurement AY 2016/2017

Pioneer Middle School of Sfax 6 Teacher: Mrs. IMEN TEKAYA BOUAZIZ

Definitions:

Alternatively referred to as digital storage, storage, storage media, or storage medium, a storage

device is any hardware capable of holding information either temporarily or

permanently.

There are two types of storage devices used with computers: a primary storage device, such

as RAM, and a secondary (auxiliary) storage device, like a hard drive. Secondary

storage can be removable, internal, or external (secondary) storage device.

Without a storage device, your computer would not be able to save any settings or

information. It is characterized by its name, type and storage capacity (that we could

measure with Multiples of byte).

Are storage devices input and output devices?

No. Although these devices do send and receive information, they are not considered an

input device or output device. It is more proper to refer to any device capable of

storing and reading information as a storage device or a drive.

Examples of computer storage

Drobo is an external storage hardware device developed

byData Robotics. It connects to a computer using USB,

FireWire, eSATA, or iSCSI, and allows a user to connect up

to four or eight SATA hard drives inside it. In the picture is

an example of a Drobo.

What makes the Drobo unique from other solutions is the ease of

connecting multiple drives into one external storage device and

having any data saved copied across the drives using RAID. Which means even if one of the drives fail

you'll still know your data is safe.

The official Drobo page is found at: http://www.drobo.com/

PIONEER MIDDLE

SCHOOL OF SFAX:

THE 8th LEVEL Lesson 1: Storage devices and

data units of measurement

8th level Unit 1 : Storage devices and data units of measurement AY 2016/2017

Pioneer Middle School of Sfax 7 Teacher: Mrs. IMEN TEKAYA BOUAZIZ

Magnetic storage devices

Today, magnetic storage is one of the most common types of storage used with

computers and is the technology that many computer hard drives use.

The hard disk is a non-volatile storage device which stores digitally encoded data on rapidly

rotating platters with magnetic surfaces.

Floppy disk

Hard drive

SuperDisk

Tape cassette

(185 TB by Sony)

Optical storage devices Another common storage is optical storage, which uses lasers and lights as its method of

reading and writing data.

Blu-Ray disc

CD-ROM disc

CD-R and CD-

RW disc

DVD-R, DVD+R,

DVD-RW,

DVD+RW disc

8th level Unit 1 : Storage devices and data units of measurement AY 2016/2017

Pioneer Middle School of Sfax 8 Teacher: Mrs. IMEN TEKAYA BOUAZIZ

a- The CD (Compact Disk)

The CD is the most common type of removable media, inexpensive but has a short life -span.

To read data from a CD, we use a CD-Drive or a CD Burner. But to save data on a CD,

we should use only a CD Burner.

There are many types of Compact Disks like: CD-R, CD-RW, CD audio, CD-ROM.

CD-R

A CD-R (Compact Disc-Recordable) is a variation of the Compact Disk invented by

Philips and Sony. CD-R is a Write Once Read Many (WORM) optical medium and

retains a high level of compatibility with standard CD readers.

CD-R has a storage capacity of 74 minutes of audio or 650 MB of data.

1 CD-RW

Compact Disc ReWritable (CD-RW) is a rewritable optical disk format. CD-RW discs are

usually produced in the most common CD-R disk capacities such as 650 and 700 MB. In

theory a CD-RW disk can be written and erased roughly 1000 times, although in practice

this number is much lower.

b. The DVD (also known as "Digital Versatile Disc" or "Digital

Video Disc")

DVD is a popular optical disc storage media format. Its main uses are

video and data storage. Most DVDs are of the same dimensions as

compact discs (CDs) but store more than six times as much data.

Variations of the term DVD often describe the way data is stored on the discs: DVD-ROM

has data which can only be read and not written, DVD-R and DVD+R can only record

data once and then function as a DVD-ROM. DVD-RW, DVD+RW and DVD-RAM can

both record and erase data multiple times.

//c. The Blu-ray Disk

8th level Unit 1 : Storage devices and data units of measurement AY 2016/2017

Pioneer Middle School of Sfax 9 Teacher: Mrs. IMEN TEKAYA BOUAZIZ

Blu-ray Disk (also known as Blu-ray or BD) is an optical disc storage media format. Its main

uses are high-definition video and data storage. The disc has the same physical

dimensions as a standard DVD or CD.

Its capacity is 25 GB. //

It could store about ………. per layer.

Capacity: Single layer: …… GB; Dual layer: …………. GB and the addition of more layers left

open as a future possibility.

The name Blu-ray Disc refers to the blue laser used to read the disc, which allows information to

be stored at a greater density than is possible with the red laser used for DVDs.

Flash memory devices

Flash memory has started to replace

magnetic media as it becomes cheaper as

it is the more efficient and reliable

solution.

Jump drive or flash drive Memory card Memory stick SSD

Network attached storage (NAS drives)

Whether you're using a laptop, tablet, or smartphone, a NAS drive lets you access your files from a

single place - it’s just like having your own personal Cloud. They're ideal for families as everyone

can have their own accounts and secure folders. You can even save and download your files from

anywhere in the world; all you need is an internet connection.

Online and cloud Storing data online and in cloud storage is becoming

popular, as people need to access their data from

more than one device.

Cloud computing : is a term used to describe services

provided over a network by a collection of remote servers.

This abstract "cloud" of computers provides massive,

distributed storage and processing power, which can be accessed by any Internet-

8th level Unit 1 : Storage devices and data units of measurement AY 2016/2017

Pioneer Middle School of Sfax 10 Teacher: Mrs. IMEN TEKAYA BOUAZIZ

connected device running a web browser. Below are some common examples of cloud

computing you have likely heard of or used.

Examples of cloud services

Amazon Web Services (AWS) and Amazon EC2 - Amazon.com provides a variety of different cloud computing services

Dashlane - Online password service to synchronize and manage passwords between all devices.

Google App Engine - A service that provides users the ability to create scalable web services that use Google's resources.

Google Calendar - A way to organize your schedule, synchronize, and share events with your friends.

Google Docs - A fantastic free solution from Google that allows you to open Microsoft Office documents as well as share them with other users with Internet access.

Microsoft OneDrive - Formerly known as SkyDrive, OneDrive is an online storage service for Windows 8 and Windows 10 users to store Windows related files, Office documents, and other files.

Online backup - There are dozens of online backup services to store your important information offsite in the cloud. For example, Mozy and Dropbox are two good examples of cloud storage and online storage backup solutions that store information in the cloud.

Windows Azure - A cloud computing solution by Microsoft that allows companies to develop and run services from their cloud.

Network media

Websites - Many popular social networking sites such as Facebook, Picasa,, YouTube and SoundCloud are also often considered parts of cloud computing.

The most common units are the bit , and the byte (or octet),

which is equivalent to eight bits.

The smallest unit of measurement of data is the bit: the shortned term for binary digits;

which can accept two possible values 0 or1 or the capacity of a system which can exist in only

two states.

8th level Unit 1 : Storage devices and data units of measurement AY 2016/2017

Pioneer Middle School of Sfax 11 Teacher: Mrs. IMEN TEKAYA BOUAZIZ

1 byte(octet) = 8 bits = 23 bits

Multiples of byte are: KB( Kilo Byte), MB( Mega Byte), GB( Giga Byte), TB( Tera Byte), etc .

1 KB= 1024 Byte (1kilo bytes= 1024 bytes=210 bytes)

1MB= 1024 KB (1Mega bytes= 1024 kilo bytes=210 kilo bytes)

1GB= 1024MB (1Giga bytes=1024Mega bytes=210 Mega bytes)

1Tera bytes = 1024 Giga bytes=210 Giga byte

1bit < 1 KB < 1MB < 1GB < 1TB

File size :A file size is the measure of space a file takes on a storage medium such

as a computer hard drive. File sizes can be measured

in bytes (B), kilobytes (KB),megabytes (MB), gigabytes (GB), terabytes (TB), and

beyond. In the picture below of files listed in Windows Explorer, the size column has

been sorted to show the largest file first. As can be seen, the first file "family-safety.jpg"

has a file size of 47 KB. The smallest file in this picture has a file size of 32 KB.

Storage device Name

size Type

Floppy disk 1.44 MB magnetic storage

device

removable and

Rewritable. Magnetic tape

(cassette/K7) 158 TB

Hard disk Up to 1TB and more

CD 650MB (up to700MB) optical storage

device

ROM : not erasable Read Only Memory

DVD 4.7 GB up to 18 GB

HD-DVD 15GB up to 30 GB RW : removable and

Rewritable. Blu-Ray 25 GB up to 50 GB

Flash disk Up to256 GB and + Flash Memory removable and

Rewritable. Memory card Up to 256GB and +

8th level Unit 1 : Storage devices and data units of measurement AY 2016/2017

Pioneer Middle School of Sfax 12 Teacher: Mrs. IMEN TEKAYA BOUAZIZ

How to find how much hard drive space is available ?

Determining the available hard drive space will vary depending upon the operating

system that is currently being used. Below is a listing of various operating systems and

the methods of determining how much space is available in that operating system.

Example : Windows 10 users

1. From the Windows Desktop, click the Start button to open the Start menu or press the

shortcut keys Windows Key + X to open the Power User Task menu.

2. In the Start menu or Power User Task menu, select File Explorer.

3. In the File Explorer window, on the left navigation pane, click on This PC.

4. After selecting This PC, you will see each drive with a small percentage bar of how much

disk space is being used, as well as a description of how much is free and the total disk

space. If you need additional information, right-click the drive and selectProperties.

Below is an example of what this may look like for the Local Disk (C:) drive.

8th level Unit 1 : Storage devices and data units of measurement AY 2016/2017

Pioneer Middle School of Sfax 13 Teacher: Mrs. IMEN TEKAYA BOUAZIZ

Things to consider before deciding what to buy :

8th level Unit 1 : Storage devices and data units of measurement AY 2016/2017

Pioneer Middle School of Sfax 14 Teacher: Mrs. IMEN TEKAYA BOUAZIZ

Activity: Try to find out the binary code of your name and then create a necklace

representing your binary coded name using two different colors only.

How many MP3's or photos can I put on my flash drive?

The number of songs or photos you can fit on a flash drive depends on several factors: Size of the flash drive or storage device.

8th level Unit 1 : Storage devices and data units of measurement AY 2016/2017

Pioneer Middle School of Sfax 15 Teacher: Mrs. IMEN TEKAYA BOUAZIZ

Length of the song or quality of the picture. Sound quality of the MP3.

Ultimately, how many songs you can fit will depend on your preference of sound quality of

the MP3's. Lower bit rate will result in lower sound quality, but more songs on the flash

drive, whereas a higher bit rate will result in higher sound quality but fewer songs on the

flash drive.

Picture (e.g. JPEG and GIF) sizes

A camera can take a picture in many different file sizes, depending on the quality of the

picture and the type of camera that is being used. Therefore, the quantity of pictures a flash

drive can store can vary depending on the size of each picture.

Generally speaking, most camera's take pictures that are around 3MB in size. A cell

phone camera will typically take a 2-3MB picture at its highest setting, and an SLR camera

taking photo's in the RAW format can be as large as 10MB.

Gigabyte (GB) : is 1,073,741,824 (230) bytes. 1,024 Megabytes, or

1,048,576 Kilobytes.

894,784 pages of plaintext (1,200 characters)

4,473 books (200 pages or 240,000 characters)

640 web pages (with 1.6MB average file size)

341 digital pictures (with 3MB average file size)

256 MP3 audio files (with 4MB average file size)

1 650MB CD

Storage devices summary

Name and photo Type Capacity Usage

Hard disk drive

……………

………………………………….

…………………………………

Floppy disk

……………

………………………………….

…………………………………

Tape

……………

………………………………….

…………………………………

8th level Unit 1 : Storage devices and data units of measurement AY 2016/2017

Pioneer Middle School of Sfax 16 Teacher: Mrs. IMEN TEKAYA BOUAZIZ

CD (Compact Disk)

……………

………………………………….

…………………………………

DVD (Digital Versatile Disk)

……………

………………………………….

…………………………………

BD (Blu-Ray Disk)

……………

………………………………….

…………………………………

HD DVD (High Definition) ……………

………………………………

Flash disk ……………

……………

………………………………….

…………………………………. Memory card

In this chapter, I learned

A storage device is a device for recording (storing) information (data)

There are many measure units of memory capacity such as Byte (B), Kilo-Byte (KB), Mega-Byte (MB), the Giga-Byte (GB) and Tera-Byte (TB)

To save data, two constraints must be taken in account: the capacity of the storage device an d the size of information