Storage devices and media

Question 1

Storage medium

Answer 1

Part of storage device that stores data

Question 2

Storage device

Answer 2

Peripheral devices to main computer system and are used to hold data whether it is on or off. These machines let us store data on the medium and read from it

Question 3

Three types of storage device

Answer 3

Magnetic storage media, optical storage media, solid state storage

Question 4

Magnetic storage media

Answer 4

Hold data magnetically. Surface of device is magnetic. Data is written on it by changing local magnetic polarity to 1 or 0. magnetic device can extract data by reading magnetic state of disk

Question 5

Optical storage media

Answer 5

Store data thanks to pits on surface burnt by laser, they present 0s or 1s. Laser can be shone onto these differences more gently and where it hits the pits, reflection is more different than it would be coming from a flat surface, differences used to store digital data

Question 6

Solid state storage

Answer 6

Different from magnetic and optical as it has no moving parts and fits directly into computer. Device and medium are the same thing. Uses only electronic circuits and flash memory

Question 7

Read/write head

Answer 7

device on each type of disk that can store data on and we can read data from it.

Question 8

Advantages of fixed hard disk

Answer 8

Fixed hard disks can

• can store v large amounts of data
• access to data is fast
• no limit for number of times medium can be resued (data deleted or rewritten)

Question 9

Disadvantages of fixed hard disk

Answer 9

Fixed hard disks can be fragile, so data stored on them should be backed up for safety because they’re stored inside computer’s case

Question 10

What type of data do fixed hard disks store?

Answer 10

• Operating system of computer
• User’s applications
• User’s data including any work user has done on computer and any files like music or videos that have been downloaded

Question 11

Where are three types of storage data stored and sent

Answer 11

Stored on hard disk and sent to computer’s RAM

Question 12

Why is storage data stored/organized on disk

Answer 12

So that direct access to it is possible.

Question 13

Fixed hard disk

Answer 13

Main storage on most personal computers, stored on one or more disks, hard disk fixed in its drive in computer so it refers to both hard disk and hard drive at the same time

Question 14

What is direct access to data

Answer 14

Every disk has index on its surface. User sends instruction to read particular file of data, read/write head looks for it in index and goes straight to that part of disk.

Question 15

Portable/ removable hard disks

Answer 15

Not connected inside computer case and can be moved around. Usually have dif interface type to computer for ex. USB, need to be more protective than fixed drive as they’re likely to get knocked as they are moved about

Question 16

Portable/removable hard disk advantages

Answer 16

• does not require external power source, unlike fixed hard drive, so you can connect it to USB and start using immediately
• small enough to carry around
• can be used easily by multiple PCs for file sharing, esp. large files
• allows scheduled automatic backup of files that is easy to set up, doesn’t matter if you forget backup
• allows quick data archiving

Question 17

Portable/removable hard disk disadvantage

Answer 17

Not recommended to switch between PCs and Macs once disk is formatted

Question 18

Magnetic tapes

Answer 18

Tapes that store data similarly to magnetic disks, except data is stored in a long line on the tape rather than scattered over surface of disk.

Question 19

Magnetic tape drive

Answer 19

Device that drives tape around read/write heads. In this device heads stay still and tape moves past it. In magnetic storage media head moves.

Question 20

Serial storage

Answer 20

In magnetic tape, read/write head will take a long time to reach far end because all other data will have to be read first.
** DATA IS STORED ONE PIECE AFTER THE OTHER **

Question 21

Sequential storage

Answer 21

Faster than serial storage, data arranged in certain order ex. alphabetical, however still very slow compared to direct access to data on hard disks

Question 22

When and why is tape storage used

Answer 22

When large amounts of data needs to be stored but speed of access isn’t important, ex storing backups where a lot of data needs to be stored.
Tape storage is cheaper and less likely to be corrupted

Question 23

When is sequential storage useful?

Answer 23

• Payroll for an entire company; not one employee will be missed, everyone’s data HAS to be read. processed once a month
• Utility bills; need to be sent to every customer on particular dates

Question 24

Optical storage media

Answer 24

CD (compact disk) DVD (digital versatile stick), both use laser to read data, however DVD uses a more precise laser which helps data be closer together and squeezed onto the surface

Question 25

Storage media

Answer 25

Something onto which data is written for safekeeping, like a tape or a disk

Question 26

It’s vital to distinguish between disks we can write to and those we can read, what are the main types?

Answer 26

ROM- read only memory, can’t be written to, only read from
R- recordable, can be written to just once and then only read from
RW- re-writable, can be written to multiple times

Question 27

CD ROMs and DVD ROMs Advantages

Answer 27

• If contents need to be protected from being corrupted it can’t be changed, used often for music or movie sale
• Software companies use them to distribute software and data files, publishers to distribute reference material like encyclopedias
• large amount of data can be stored without being easy to damage
• fairly inexpensive

Question 28

CD Rs and DVD Rs Advantages

Answer 28

• used for copy files, an archive etc..

- you can write what you want on them then material is protected

Question 29

CD ROMs and DVD ROMs disadvantage

Answer 29

also a disadvantage that data cannot be changed, if someone is bored of a movie for ex, they cannot access anything new

Question 30

CD Rs and DVD Rs Disadvantages

Answer 30

• Less useful for making regular backups

- As they can be written to only once, not all CD/DVD devices can play them

Question 31

CD RWs and DVD RWs Advantages

Answer 31

• ideal for moving files from one computer to another, ex taking work to school you did at home
• not easy to damage
• store large amounts of data
• can be reused over and over again
• • ideal for taking backups

Question 32

CD RWs and DVD RWs Disadvantages

Answer 32

• since it stores a lot of data and this data can be rewritten, data is easier to steal

Question 33

DVD RAM Advantage

Answer 33

surface can be written on more often than RW

• access to data is faster
• can read and write at the same time
• greater capacity

Question 34

DVD RAM disadvantage

Answer 34

• cant be used in ordinary DVD player

- more expensive than other optical storage media

Question 35

Blu-Ray disks

Answer 35

• can preform high speed transfers and have much larger storage capacities than other optical storage media
• can record and play back video in very HD

Question 36

Blu- Ray disk disadvantage

Answer 36

• very expensive

Question 37

Solid state storage devices

Answer 37

• have no moving parts
• similar tech to RAM and ROM but don’t need electricity
• small and portable, can store a lot of data
• straightfoward to use as many are designed to directly fit computer port

Question 38

Memory stick and pen drive

Answer 38

two names for same thing

they are used for backups and transport of info from one device to another

Question 39

Flash memory cards

Answer 39

• portable memory
• fits in usb port
• flat and looks like a card
• can be CF (computer flash) or SD (secure digital)
• used in small electronic devs
• store media.. movies, photos, etc