Storage

Question 1

Secondary storage non volatile- what does this mean

Answer 1

It means that data wont be lost in this type of storage if the system suddenly gets switched off

Question 2

Give three uses of secondary storage-

Answer 2

Store a document for future use
Store an application, ready to be loaded to the ram when the user opens the application
virtual memory

Question 3

Define virtual memory-

Answer 3

It is a storage space in a computer
which stores programs and instructions until they are needed or being used

Question 4

Define a motherboard

Answer 4

It is a circuit in the computer with connectors through which other components connect.

Question 5

What are internal and external storage devices

Answer 5

Internal storage devices are storage devices that are directly connected to a computers motherboard.
External storage devices are storage devices that connect to the the device via interfaces such as ports or adapters on the computers exterior

Question 6

What are storage devices

Answer 6

Storage devices are used to store data and software which are used in a computer systems.

Question 7

What is a hard disk drive?

Answer 7

A hard disk drive contains hard disk media and they can provide connection to a devices motherboard either directly or by a wireless adapter such as WIFI or wired connection such as a USB cable

Question 8

What is a solid state drive

Answer 8

a solid state drive commonly referred to as a flash drive contains flash media. Other wise it is identical to a hard disk drive

Question 9

Describe how connection can be provided to these drives via wireless adapters such as wifi-

Answer 9

A type of secondary storage known as network attached storage, which contains multiple Hard disk drives and solid state drives, is directly connected to a router via a SATA/IDE cable. A device can wirelessly communicate with that router and access the data and software stored on the NAS so that it can be used by the computer system.

Question 10

Define optical drives

Answer 10

Optical disk drives contain optical disk media.

Question 11

define backwards compatibility with an example

Answer 11

The ability to be used with older technology without needing to be specifically adapted. For example a blue ray drive adapted to read blue ray disks can jolly well read DVDs and CDs

Question 11

define backwards compatibility with an example

Answer 11

The ability to be used with older technology without needing to be specifically adapted. For example a blue ray drive adapted to read blue ray disks can jolly well read DVDs and CDs

Question 12

Describe hard disk media

Answer 12

Hard disks are made up of many concentric platters. These platters make up a cylinder which spins on a central spindle. It also has an/multiple actuators depending on the type of hard disk which read and write heads are mounted on.

Question 13

What affects the amount of time taken by the read and write heads to access the data on the disk

Answer 13

the speed at which the disks spin around the spindle

the speed at which the read and write heads are moved across the tracks by the actuator arm.

Question 14

How do the read and write heads read and write data on the platters

Answer 14

when reading, the R/W heads are able to convert the magnetic field into electric charge and when writing converts the electric charge into a magnetic field.

Question 15

What is seek time and what is it typically measured in?

Answer 15

Seek time refers to the amount of time taken by the read and write head to locate the area on the disk in which the data to be read is stored.
4 -15 miliseconds

Question 16

What are spin speeds measured in and their typical values

Answer 16

5400 to 7200 revolutions per minute

Question 17

Optical media
Describe CDs, DVDs and Blue Ray Disks
Hint: You keep on forgetting one crucial detail about Blue ray disks.

Answer 17

CD disks- Can store up to 700MB worth of data.
Data is written on the CD disks via laser which writes data on the plastic layer of the disk beneath other layers of aluminum and acrylic.
DVD disks- These disks use a red light laser which has a shorter wavelength than the laser used by CDs to write data on the disks and therefore can store more data.
Single sided single layered DVD disks can store up to 4.7 GB and double layered double sided disks can store up to 20 GB worth of data.
Blue ray disks use violet light lasers to write data on the disk which have an even shorter length and can store data at a much higher density than DVDs. 25 GB on single side and 50 GB on double side.
It uses sophisticated scratch protection coating which makes it less susceptible to damages like CDS or DVDS.

Question 18

What makes flash media more energy efficient and portable than HD media?

Answer 18

Unlike HD media, Flash media doesn’t contain moving parts

Question 19

What was magnetic tape initially used for and what is it used for now?

Answer 19

It was initially used for recording sounds but can now record data

Question 20

define data access speed

Answer 20

how quickly data can be read from or written to media

Question 21

define bits

Answer 21

a single unit of information which holds two value- 1 or 0.

Question 22

Arrange all the media we just discussed in a table in terms of data access speed, maximum storage capacity, uses, cost per gb, portability.

Question 22

Arrange all the media we just discussed in a table in terms of data access speed, maximum storage capacity, uses, cost per gb, portability.

Question 23

How does each type of media interpret 1s and 0s

Answer 23

Hard disks can change the the magnetic charge of a platter to positive or negative depending on the value being a 1 or 0.
optical media uses tiny bumps on the surface of the disk to represent 1s and 0s.
Magnetic tapes can change the magnetic charge on the tape to positive or negative depending on the value being 1 or 0.
Flash media uses different levels of electric charge held in tiny individual cells to represent 1s and 0s.

Question 24

Read and write heads

Answer 24

the part of the disk drive that passes across the platters on a very thin layer of gas above the platters

Question 25

seek time

Answer 25

the time it takes to locate the area on the disk where the data to be read is stored

Question 26

capacity

Answer 26

the amount of data that can be stored on data