Storage Device & MediaBy Nicole Lewis

HOW DOES IT WORK?When inserted into a drive, the magnetic tape is spun around rapidly, much like a CD.While spinning, the read/write head of the disk stops at the empty track on the disk. The computer, before sending any information to the disk, quickly checks for things like system stability and whether or not the necessary space is free on the disk.

Magnetic Devices – Floppy Disk and Drives

WHAT IS IT USED FOR?

A floppy disk drive used in computers for data transfer, storage and backup of small amounts of data, as well as installation of programs and driver updates.A floppy disk drive accesses data recorded on small, removable diskettes such as floppy disks.

Magnetic Devices – Floppy Disk and Drives

Advantages DisadvantagesIt is really cheap. Easily destroyed by dust and dirt

or magnetic fields. (If you put the disk next to anything magnetic, it could wipe everything off.

The data is write protected. Write protection prevents the data from being easily destroyed.

Accessing data would be very slow.

It was easy to transfer data from one computer to the next.

Storage capacity was limited to only 1.44 MB. (Cannot have full length songs or have pictures taken on digital cameras today.

HOW DOES IT WORK?

Magnetic Devices – Hard Drives

WHAT IS IT USED FOR?

The hard drive is what a computer uses to store all of its data and programs.

Magnetic Devices – Hard Drives

Advantages DisadvantagesStores and retrieves data much faster than a floppy disk or CD-ROM.

Hard disks eventually fail which stops the computer from working.

Usually comes inside of the computer already for you.

The disk is fixed inside the computer and cannot easily be transferred to another computer.

Large storage capacity. A crash could lead to the lose of everything on that hard drive.

HOW DOES IT WORK?

Data is recorded onto a CD in a clockwise spiral from the centre. Its recorded and read in a series of lands and pits. Any land that the laser hits is reflected to the read head and is recorded as a 1 or a 0. They are counted in groups of 14 and then converted into standard 8-digit data.

Optical Drives – CD ROM

WHAT IS IT USED FOR?

It is used too store music, games, programs, installation CDs, multimedia applications, video and images.

Optical Drives – CD ROM

Advantages DisadvantagesIt is easily transportable and is compatible with any other PC or laptop .

The data can also be easily destroyed simply by breaking or cutting the CD.

The data can also be easily destroyed simply by breaking or cutting the CD.

Once created the data cannot be changed or updated.

It can be protected so that the data won't be erased by accident.

It can easily be lost or stolen.

HOW DOES IT WORK?

A CD-R disc needs to allow the drive to write data onto the disc. For a CD-R disk to work, there must be a way for a laser to create a non-reflective area on the disc. A CD-R disc therefore has an extra layer that the laser can modify.

Optical Drives – CD-R

WHAT IS IT USED FOR?

To store recorded data. Music, voice records. Etc.

Optical Drives – CD-R

Advantages DisadvantagesThey are cheap and fast. Can only record on it once.

Is suitable for applications that requires ‘burning of data’.

Can only store up to around 700mb of data.

HOW DOES IT WORK?

A clear dye layer covers the CD's mirror. A write laser heats up the dye layer enough to make it opaque. The read laser in a CD player senses the difference between clear dye and opaque dye the same way it senses bumps -- it picks up on the difference in reflectivity.

Optical Drives – CD-RW

WHAT IS IT USED FOR?

Allows data, such as music, voice records etc., to be stored on the disk over and over again.

Optical Drives – CD-RW

Advantages DisadvantagesCan read discs made by different CD-R and CD-RW devices.

CD-RW’s media can be written/erased over and over.

CD-RW’s media can be written/erased over and over.

CD-RW drives are slower than CD-R drives.

CD-RW devices can write to both CD-R and CD-RW media.

Most players don’t work with CD-RW’s.

HOW DOES IT WORK?

A laser is used to read and store data onto the disk.

Optical Drives – DVD

WHAT IS IT USED FOR?

Storing multimedia files such as MP3, digital images and video clips.

Optical Drives – DVD

Advantages DisadvantagesThey are cheap and fast. Easily destroyed/damaged.

DVD drives can read CD’s. DVD’s do not work in CD drives.

The sound and picture quality is amazing.

Cannot put data on it more than once.

HOW DOES IT WORK?

DVD-ROMs has an optical path, a drive head which holds the laser, a lens and devices called photodiodes, which read the light bouncing from the DVD's pits.

Optical Drives – DVD ROM

WHAT IS IT USED FOR?

For the distribution of movies where you can only read data off of the disk. It can also be used to read the data off of a CD.

Optical Drives – DVD ROM

Advantages DisadvantagesCannot steal because you need to right drive to read the data on the DVD ROM.

Can be easily broken.

Can hold up to 700MB of data which is 74 minutes of audio.

It cannot put data more than once.

HOW DOES IT WORK?

Optical Drives – DVD + RW

WHAT IS IT USED FOR?

To write and read data from a DVD. They are also able to be written to and not just read from.

Optical Drives – DVD + RW

Advantages DisadvantagesIt is about 4.7 GB. They can be expensive.

It is rewritable. Many players can not read DVD RW’s.

N/A Because they are rewritable, the data can easily be deleted.

HOW DOES IT WORK?

A plastic film tape is coated with an iron oxide coating. That tape is passed by and in contact with a recording head, that consists of a metal core with wire windings on it.

Magnetic Tape

WHAT IS IT USED FOR?

To store the data such sound, video and recordings, on a plastic magnetic coated tape which is stored on a reel.

Magnetic Tape

Advantages DisadvantagesCan be set up to work over night or through the weekend.

Takes ages for the data to be found on the tape. Could be quite slow.

Really, really cheap. The data can be corrupted if place next to anything magnetic.

Can store large amounts. Up to 1Terabyte.

Needs a special type of equipment to record and read the data.

HOW DOES IT WORK?

A flash drive consists of a PCB that is, a printed circuit board. It is covered in a plastic or rubber casing, which makes it sturdy.Once plugged in, a flash drive enters the emulation mode which means it emulates a hard drive thereafter.

Flash/Pen Drives

WHAT IS IT USED FOR?

To store data such a photographs and music. Can be used for internal storage on tablet computers that have no room for the normal hard drive.

Flash/Pen Drives

Advantages DisadvantagesLight weight. So small it is easily misplaced or

stolen without knowing.

Has a large capacity storage. Fast access.

Can be used as a backup. Do not have a high transfer rate as magnetic hard disk drives.

Flash memory is non-volatile. A virus can be easily passed from one computer to the next.

HOW DOES IT WORK?

Memory Card Drives & Memory Cards

WHAT IS IT USED FOR?

Store photographs and other data, usually on digital cameras.

Memory Card Drives & Memory Cards

Advantages DisadvantagesMany computers and printers have drives that will read the data on different sized memory cards.

Cannot be attached or read on the computer without proper hardware.

It’s small. It can sometimes run slow.

Can be used in digital cameras, mobile phones and MP3 players.

Can be quite expensive.