Components of a Computer System

Question 1

What is a computer?

Answer 1

A computer is a machine that processes data

Question 2

Define hardware.

Answer 2

The physical stuff that makes up your computer system

Question 3

Define software.

Answer 3

The programs that a computer system runs

Question 4

Give some examples of system software.

Answer 4

1) operating systems

2) utilities

Question 5

Give some examples of application software.

Answer 5

1) word processors
2) web browsers
3) email clients
4) games

Question 6

What is an embedded system.

Answer 6

Embedded systems are computers built into other devices

Question 7

Explain the role of the control unit in the CPU.

Answer 7

1) to execute program instructions by following the fetch-decode-execute cycle
2) controls the flow of data inside the CPU (to registers, ALU, cache) and outside the CPU (to main memory and input/output devices)

Question 8

What does ALU stand for?

Answer 8

Arithmetic Logic Unit

Question 9

What does the ALU do?

Answer 9

1) completes simple addition and subtraction
2) compares the size of numbers
3) can do multiplications and divisions using repeated addition and subtractions
4) performs logic operations such as AND, OR and NOT
5) performs binary shifts

Question 10

What is cache?

Answer 10

Very fast memory in the CPU

Question 11

What is cache used for?

Answer 11

To store regularly used data so that the CPU can access it quickly the next time it’s needed

Question 12

Describe the function of the clock.

Answer 12

Used to synchronise when instructions will be carried out (like a metronome)

Question 13

What is a bus?

Answer 13

A collection of wires that are used to transmit data between components of the CPU and other parts of the computer system

Question 14

Describe what happens at each stage of the CPU fetch-decode-execute cycle.

Answer 14

1) fetch - the control unit reads the memory address of the next CPU instruction. The instruction stored in that address is copied from memory to one of the registers. The memory address in the control unit is incremented to point to the address of the next instruction, ready for the next cycle
2) decode - the instruction that was copied from memory is decoded by the control unit. The control unit prepares for the next step
3) execute - the instruction is performed

Question 15

What is volatile memory?

Answer 15

Temporary memory that requires power to retain its data

Question 16

What is non-volatile memory?

Answer 16

Permanent memory that keeps its contents even when it has no power

Question 17

What does RAM stand for?

Answer 17

Random Access Memory

Question 18

Describe how RAM is used in a computer system.

Answer 18

To store all data, files and programs when they’re being used

Question 19

Explain why ROM is required by a computer system.

Answer 19

It contains all the instructions a computer needs to properly boot up. These instructions are called the BIOS (Basic Input Output System)

Question 20

Which usually has more RAM: an embedded system or a non-embedded system?

Answer 20

Non-embedded systems

Question 21

What characteristics of a processor may affect its performance?

Answer 21

1) clock speed
2) CPU cores
3) cache size
4) cache type

Question 22

Define primary storage.

Answer 22

The memory areas that the CPU can access directly

Question 23

Define secondary storage.

Answer 23

Non-volatile storage that isn’t directly accessible by the CPU

Question 24

Give some examples of primary storage.

Answer 24

1) CPU registers
2) cache
3) ROM
4) RAM

Question 25

Give some examples of secondary storage.

Answer 25

1) magnetic hard disk drives
2) solid state drives
3) CDs
4) SD cards

Question 26

What are the advantages of a HDD compared to a SSD?

Answer 26

1) HDDs are cheaper
2) both are high capacity, but HDDs are higher
3) HDDs have a longer read/write life than SSDs - SSDs can only be written a certain number of times before they begin to deteriorate

Question 27

What are the advantages of a SSD compared to a HDD?

Answer 27

1) SSDs are faster
2) SSDs don’t need defragmenting
3) SSDs are more shock-proof than HDDs
4) HDDs make some noise, SSDs are silent

Question 28

Why might someone choose magnetic tape as a form of storage?

Answer 28

It has a very high capacity and an extremely low cost per GB

Question 29

List some uses of flash memory.

Answer 29

1) cameras
2) smartphones
3) tablets

Question 30

What are the pros of optical discs?

Answer 30

1) they’re very cheap per GB
2) portable
3) won’t be damaged by water or shocks

Question 31

What are the cons of optical discs?

Answer 31

1) they are easily scratched
2) modern devices don’t have optical drives
3) they can’t compete with flash storage devices due to their low capacity per disc, very slow read/write speeds and poor reliability of RW discs

Question 32

What are the pros of cloud storage?

Answer 32

1) users can access files from any connected device
2) files can be shared with others or made public
3) easy to increase how much storage is available
4) no need to buy expensive hardware to store data
5) no need to pay IT staff to manage the hardware
6) cloud host provides security and backups for you
7) can be cheap/free if not much storage is required

Question 33

What are the cons of cloud storage?

Answer 33

1) need connection to the Internet to access files
2) upload/download speed depends on bandwidth
3) dependent on host for security and backups
4) stored data can be vulnerable to hackers
5) unclear who has ownership over cloud data
6) subscription fees for using cloud storage may be expensive in the long term

Question 34

What are the functions of an operating system?

Answer 34

1) to communicate with input and output devices via device drivers
2) provide a platform for applications to run on, and a user interface
3) control memory management and allocation
4) organise the CPU and its processing tasks
5) deal with file management and disk management
6) manage system security and user accounts

Question 35

Explain how device drivers are used in a computer system.

Answer 35

Device drivers acts a ‘translator’ for the signals between the OS and the device

Question 36

Describe how the OS manages applications.

Answer 36

1) provides a platform for applications to run on and multitasks
2) allows applications to access hardware, peripheral devices, RAM and secondary storage
3) provides a user interface that applications are accessed through

Question 37

Describe how the OS manages memory.

Answer 37

1) decides if applications or features have been used recently - if not, they may be removed from memory
2) manages how much RAM a program has access to
3) when running multiple applications at once, will make sure that they don’t overwrite or interfere with each other by allocating certain applications certain memory addresses, keeping their processes in separate locations

Question 38

Describe how the OS manages the CPU.

Answer 38

1) scheduling to determine the most efficient order for the CPU to execute instructions
2) interrupts the current CPU process if a higher-priority process becomes available

Question 39

Describe how the OS manages files and disk space.

Answer 39

1) manages the hard disk - splits the physical disk into storage sectors, decides which sector to write data to, and keeps track of free space on the disk
2) organises and maintains the hard disk with utility software like defragmentation software

Question 40

Give ways in which an OS might keep your files secure.

Answer 40

1) user account control
2) anti-theft measures
3) passwords
4) pins
5) fingerprint scanners
6) retina scanners

Question 41

List some types of utility software and explain what they do.

Answer 41

1) defragmentation - puts the files back into one block and collects the free space together
2) disk health - scans the drive for problems and fixes issues where possible
3) compression - reduces the size of files so they take up less disk space
4) encryption - scrambles (encrypts) data to stop third-parties from accessing it
5) backup - copies the computer system’s files and settings and stores them externally so that they can be restored in the event of data loss
6) virus scanners - inspects each file on your computer, looking for virus
7) system cleanup - go through and get rid of temporary files left on your hard drive which can end up taking up lots of space unnecessarily