Paper 1 Flashcards

(54 cards)

1
Q

What is the purpose of the CPU?

A
  • Process data and instructions
  • To control the rest of the computer system
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2
Q

What are the components of the CPU and what does each one do?

A

Control Unit – Does the FDE cycle, moves data around the system
Arithmetic Logic Unit – Performs arithmetical and logical decisions, acts as a gateway between primary memory and secondary storage
Cache – A small amount of high-speed RAM built directly in the CPU
Clock – sends out regular pulses to keep the components coordinated, this is measured in hz
Buses – High speed internal connectors for data transfer between components:
Address Bus – Carries the memory address from the processor to the primary memory in input / output devices
Control Bus – Carries the clocks signals, carries signals from the CU to other components
Data Bus – carries actual data

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3
Q
  1. What are the Von Neumann Registers and what is the role of each one? / FDE Cycles
A

Program Counter – Holds the address of the next function to be fetched from the primary memory
Memory Address Register – holds the address of the current instruction that is to be fetched from the memory
Memory Data Register – Holds the contents found in the address held in the MAR
Current Instruction Register – Holds the instruction that is currently being executed
Control Unit – Receives the data and sends a signal to update the program counter
Accumulator – Data is processed here
ALU – Holds the data being processed and the result of it

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4
Q

Give three ways that the performance of a CPU can be improved

A

Faster clock speed
Bigger cache size
More cores

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5
Q

What is Clock Speed measured in and how does it affect the performance of a CPU?

A

HZ, the higher the clock speed the more signals are sent

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6
Q

What is Cache size measured in and how does it affect the performance of a CPU?

A

MHz, the higher the hertz the faster the speed

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7
Q

How does number of cores affect the performance of a CPU?

A

The more cores there are, the more tasks it can multitask and more instructions it can complete

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8
Q

Give three examples of embedded systems / general purpose computers

A

Watches, fitness trackers, GPS

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9
Q

Why do computers need primary memory?

A

They need it to hold instructions that are currently in use

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10
Q

What are the differences between RAM and ROM?

A

RAM is volatile while ROM is non-volatile. RAM stores instructions that are currently in use while ROM stores data long-term

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11
Q

What is stored in ROM?

A

Instructions and data that is needed for the computer to turn on

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12
Q
  1. What is stored in RAM?
A

Data, programs and instructions that are currently in use

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13
Q

What is virtual memory?

A

The use of secondary storage as temporary primary memory, it exchanges data between primary and secondary depending on what’s being used in a process called “swapping”. Because of this process and the fact that secondary storage takes much longer to access, this slows down the computer’s performance.

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14
Q

. What is secondary storage?

A

Non-volatile, long-term storage

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15
Q

What are the types of storage? Give two benefits and two negatives of each

A

Magnetic / Hard Disk Drives:
+ Cheap
+ High in capacity
- Can be damaged in dropped
- Vulnerable to magnetic fields
Optical Devices (Blu Ray Disk):
+ Nonvolatile Storage

+ Easily Transportable
- R media can only be written to once
- ROM media can not be written to at all
Solid State Devices (Electrical Storage):
+ Portable
+ High-speed
- Expensive
- Vulnerable to power loss

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16
Q

What characteristics should you consider when comparing types of storage?

A

Durability, storage capacity, speed, price, utility

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17
Q

List the units of data storage in size order from Bit to Petabyte
Bit

A

Bit
Byte (x8 of previous)
Megabyte (x1000 of previous)
Kilobyte (x1000 of previous)
Gigabyte (x1000 of previous)
Terabyte (x1000 of previous)
Kilobyte (x1000 of previous)

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18
Q

Why do computers store data as binary?

A

It is the simplest way for computers to understand and store data, easiest for the computer to process

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19
Q

How is the size of a sound file calculated?

A

Sample rate x bit depth x duration

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20
Q

How is the size of an image file calculated?

A

Image height x image width x colour depth

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21
Q

What is the most significant bit?

A

The left-most number

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22
Q

What is the least significant bit?

A

The right-most number

23
Q

What is an overflow error?

A

When the calculation requires more bits than it can store

24
Q

What is a character set? – give two examples.

25
How are images represented using binary?
A binary number of correlates to a colour. The more bits in one pixel the greater the colour depth.
26
What is metadata?
Data about the file itself including the author, data created, file type, name
27
How is sound represented using binary?
Audio is recorded and a binary-to-digital converter coverts each sample (slice of audio) into a binary number, many of these samples are stringed together to form the intended audio. Bit depth is how many bits are used to record each sample, the usual is 16 but sometimes 24. Sample rate is the number of files recorded at a given time.
28
What are the two benefits of file compression?
The data is smaller so there is more room in storage for other things, it also means it will be able to be transferred faster.
29
Describe the two types of compression
Lossy: This is when the quality of the data is reduced in order to reduce the size For example: - Reducing the colour depth - Reducing the bit depth - MP3 and JPEG files are forms of lossy compression for audio and video respectively Lossless: This is when files are reduced without a less of data
30
What is the difference between a LAN and a WAN? Give an example of each
LAN is a local area network for example a school computer network, WAN is a wide area network for example the internet
31
What factors will affect the performance of a network
Number of devices connected to the network Amount of traffic Bit-rate Network latency Number of transmission errors
32
Describe the differences between client server and peer to peer networks
Client to server networks is data transfer is done through a server, which acts as a medium between people for communication Peer to peer is when data transfer is done directly through data exchange between two computers, peers store their own files which can be accessed by others in the peer-to-peer network
33
Describe five pieces of hardware used when setting up a LAN
Each computer must have a Network Interface Card or a Wireless Network Interface Controller A transmission medium (Ethernet, WiFi) A point to connect to (Hub, router, switch)
34
Give two benefits and two negatives of cloud storage
+ Files can be accessed from any device + Storage is in theory limitless - No guarantee of backups - Information may get in to the wrong hands without a means of prevention
35
Explain the role of a DNS when loading a webpage.
A user enters a URL on a browser, this is forwarded to a DNS which retrieves the IP that is linked to that URL, the IP is sent to the browser, which is used to locate the desired server and access it.
36
What is a network topology
The arrangement in which nods in a network are connected
37
What are the advantages / disadvantages of star and mesh topologies?
Star: + Failure of a node will never affect any other nodes + Easy to connect new nodes - If the switch fails then the whole networks fails - Requires a lot of cable which is hard to set up and can be expensive in large areas Mesh: + Messages should always get through as they have many routes to travel + Messages can be quick if the route to the intended recipient is short - Full-mesh networks are hard to set-up as they require many connections - Many connections require a lot of maintenance
38
What are the benefits / negatives of Wi-Fi and of Ethernet?
+ New nodes can easily be added + Users can operate anywhere and be connected - Wi-Fi signals can be intercepted by unauthorized users - Wi-fi signals have a limited range
39
What is encryption?
The process of encoding data so that it can only be accessed by authorised users
40
What is the difference between IP addresses and MAC addresses?
A unique number given to a device when connected to a network so that other nodes can identify which node to send messages to. If a node has a static IP address it will always have the same number, if a node has a dynamic IP address its number will change depending on what Ips are available at a given time. A MAC address is a unique serial number assigned to every Network Interface Card which allows a network to uniquely identify any device whether it has a dynamic IP address or not
41
What are network standards?
Rules that allow devices to communicate with each other
42
What is a network protocol?
Rules that govern communication
43
List seven network protocols and explain when they are used
TCP enables communication over the internet HTTP governs communication between a webserver and client, HTTPS includes secure encryption FTP governs the transmission of files over the internet SMTP governs sending Emails POP and IMAP govern receiving Emails
44
What are network layers and why are they used?
Breaking up sending messages into separate components and activities
45
List and explain six threats to a network
Malware: Malicious software designed to hack a system Phishing: Pretending to be someone you are not in order to trick someone into sending personal information Brute Force: A system that tries different passwords over and over in order to try to log in Denial of Service: Bombarding a server with requests to overload it and stop it from doing its task SQL Injection: Inputting SQL as data to confuse a data system
46
List and explain seven ways to prevent threats to a network
Penetration Testing: Authorised users probe the network for potential weaknesses to try to identify and fix them Network Forensics: Data is gathered and analysed to identify potential unauthorized access User access levels: Admins control what information users of a network can access Network Polices: Policies that govern how a network should be used and how to keep your computer safe. Examples: Use strong password, users cannot connect unauthorized USB devices
47
What is the purpose of operating systems?
A suite of programs that manages or controls a computer system
48
List and describe 5 functions of an operating system
Providing a user interface Managing files Managing peripherals Managing Users Managing computers memory
49
What is utility software? (Give three examples)
Software that helps maintain the computer system: Encryption Software Backup Software Defragmentation software Encryption software
50
What is disk defragmentation?
Software that takes fragmented stored on a hard disk and places them together so that they can run continually
51
List (with dates) the legislation taught at GCSE Computer Science:
Data Protection Act 1998/2018: Personal data must be handled ethically Computer Misuse Act 1990: Illegal to make changes to data stored on a computer unless the owner permits you to, illegal to access information on a computer for the purpose of blackmail, illegal to access information on a computer unless the owner permits you to Copyrights, Designs and Patents Act 1988: Protects someones right to own something you created online Creative Commons Licensing: Helps copyright owners share work while keeping the content, it makes it so people can use content as long as they do not make money off it and credit the author Freedom Of Information Act 2000: The public has the right to access any information from public sector organisations
52
What is the difference between Open Source and Proprietary software?
Open Source: Free of copyright and available to anyone Proprietary: Copyrighted often have to pay to access
53
Define e-waste, e-commerce and digital divide:
Digital Divide is the divide is the divide between those who are comfortable using technology and those who are not EWaste is the left over technology that is left behind at landfill because of the new technology that has come out Ecommerce is businesses operating online
54
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