storage devices by: tolga, keeshan, adam. read only memory (rom) it’s a class of storage media...

Storage Devices

By:

Tolga, Keeshan, Adam

Read Only Memory (ROM)

• It’s a class of storage media used in computers and other electronic devices.

• It’s a special kind of memory that gives instructions which the computer uses when it ‘boots up’.

• The ROM is attached to the Motherboard.

• The data is not erased when the computer is turned off.

Random Access Memory (RAM)

• RAM memory is known as ‘volatile memory’

• Is a form of computer data storage.

• RAM, usually in the computer main memory or primary storage

• Working memory

Hard Disk

• A hard disk drive is the physical medium that is used to store any and all information.

• Advantage: Stores data on a long term basis.

• Large storage capacity• Disadvantage: eventually fail which stops

the computer working• Big and bulky

Floppy Disk

• Floppy disks are one of the oldest types of portable storage devices still in use, having been around since the 1980s.

• Advantage: small and compact for its time

• Disadvantage: old and out of date.

• No built in floppy disk drives in new computers

Zip Disk

• Zip disks are pretty much obselete now. However, they were very popular as a back before CD-RW’s were cheap enough to be bought by everyone.

• Advantage: a lot of storage back in it’s time.

• Disadvantage: NOBODY uses it

Magnetic Tape

• Large organizations who need to back up their systems daily tend to use magnetic tapes to store their data.

• Advantage: cheap

• Disadvantage: serial access so can be quite slow to access data.

• Need a special piece of equipment to record and read the data on the tape.

Compact Disks (CD)• CD-ROM - CD Read Only Memory. This means that when you buy

the disk, it already has the data or program stored on it. You can read it, but can't save to it. An example would be a music CD that you buy from a shop.

• CD-WORM - CD Write Once Read Many. This means that you are able to save to this disk one time, so you can store your data or an application on it of your choice. However, once you have saved onto the disk once, you can access the data many times but can't save onto it again.

• CD-RW - CD Read Write. This means that you can save data to your disk over and over again, just like you can with a floppy disk.

• Advantage: Small and portable.• Cheap• Disadvantage: Fairly fragile easy to scratch and snap.• Slower access than hard disk.

DVDs

• DVDs are amongst the most common methods of copying and backing up data at home.

• A DVD is similar to a CD in that it is an optical device and that a laser is used to store the data and read the data.

• Advantage: large storage capacity• Disadvantage: DVDs don’t work in CD

drives.

Flash Memory

• Flash memory storage devices are typically small, lightweight, removable and rewritable.

• They consist of a small printed circuit board which is encased in plastic or metal casing.

• Advantage: They are more compact and portable than floppy disks or CDs/DVDs.

• Disadvantage: At the moment, the cost per megabyte of storage is more expensive than floppy disks, CDs or DVDs.

QUIZ

Which of the following is the smallest unit of data which can be stored?

1. Megabyte

2. Bit

3. Kilobyte

4. Big byte

Wawawiwa

• You got it wrong HIGH FIVE!

Bit

• CORRECT! I like !

Next Question

Kilobyte

• Wrong again…

Megabyte

• Try again faillllureeee

The word Bit is made from Binary Digit?

• True

• False

True

• Correct

Next Question

False

• wrong

Correct size of a kilobyte?

• 1024 bytes

• 1024 megabytes

• 1000 bytes

• 1000 megabytes

1024 bytes is correct …

Next question

Wrong..

• wrong

Wrong again

Wrong again

ROM is volatile memory?

• False

• True

CORRRRRRRRRRRREEECT

Next question

My suit is black not

this answer is right pause not.

The hard disk stores the application that you regularly use on your

computer

• True

• False

Correct

Wrong…