IGCSE Computer Science 0478 Paper 13, May/June 2024

8

2048

nibble

16 bits used to represent each colour in the image

The file size will decrease

1010

0010

1111

2607

1

9

B

411

It is easier/quicker to read/understand/debug // It is a shorter representation of binary // It takes up less screen space

HTML colour codes // URL // Memory dump // IP address // MAC address // Assembly language // Error codes/messages // ASCII/Unicode

HTML colour codes // URL // Memory dump // IP address // MAC address // Assembly language // Error codes/messages // ASCII/Unicode

Correct working (e.g. flip and add)

11100111

optical: Pits and lands are created on a reflective surface.

solid-state: NAND or NOR technology is used.

magnetic: Platters are spun that are divided into tracks and sectors.

magnetic: Electromagnets are used to read and write data.

solid-state: Transistors are used as control gates and floating gates.

optical: A red or blue laser is used to read and write data.

C

It is directly accessible by the CPU

touch screen

microphone

keyboard

Data can be collected without human intervention // Gathers data faster than a human // It will be accurate at taking readings // It can take readings continuously (24/7) // It can take readings in dangerous environments

Data can be collected without human intervention // Gathers data faster than a human // It will be accurate at taking readings // It can take readings continuously (24/7) // It can take readings in dangerous environments

Temperature: Checking whether the water in a kettle is boiling // Monitoring the temperature in a room that is climate controlled

Humidity: Checking whether the air is dry enough in a spray-painting garage // Checking whether the air is moist enough in a greenhouse

Infra-red: Detecting motion in a room for a security system // Detecting whether a person is approaching automatic doors

Magnetic field: Counting vehicles that cross a bridge // Monitoring vehicles that enter a car park

Bits beings sent one at a time

Bits being sent over a single wire

Data can be sent to and from the web server/network component/computers …

… not at the same time

Bits will not be skewed // Bits are sent in order // Less chance of error // Less crosstalk/interference // Data can be sent over a long distance (if needed) // It is possible to download and upload data to the web server // Higher bandwidth than full duplex

Bits will not be skewed // Bits are sent in order // Less chance of error // Less crosstalk/interference // Data can be sent over a long distance (if needed) // It is possible to download and upload data to the web server // Higher bandwidth than full duplex

The transmission of data may be relatively slow // Data cannot be sent and received at the same time // May be more data collisions

DDoS // DoS // Hacking // Malware // by example // Brute-force attack

DDoS // DoS // Hacking // Malware // by example // Brute-force attack

DDoS // DoS // Hacking // Malware // by example // Brute-force attack

Can limit the number of requests sent to the web server at a time // Can process common requests that will not need to enter the network // Act as a firewall // Examine incoming data to the webserver/network // Can have set rules/criteria for data to meet // Can have a blacklist/whitelist/list of IP addresses to block // Blocks traffic that doesn’t meet criteria // Closing certain ports

Can limit the number of requests sent to the web server at a time // Can process common requests that will not need to enter the network // Act as a firewall // Examine incoming data to the webserver/network // Can have set rules/criteria for data to meet // Can have a blacklist/whitelist/list of IP addresses to block // Blocks traffic that doesn’t meet criteria // Closing certain ports

The users type the URL into the address bar/web browser

The web browser sends the URL to the DNS

The DNS searches for the matching IP address

The DNS returns the IP address to the web browser

If the DNS cannot find the IP address it sends the URL to the next DNS

The web browser sends a request to the IP address/web server

To process instructions/data

To run the fetch–decode–execute cycle

To temporarily store data/instruction/address // To allow immediate access to data during the FDE cycle

Memory address register // MAR

Memory data register // MDR

Accumulator // ACC

To execute instructions // To perform calculations // by example // To perform logical operations // by example // To store interim results of calculations // Stores/reads/writes data to/from the accumulator

To execute instructions // To perform calculations // by example // To perform logical operations // by example // To store interim results of calculations // Stores/reads/writes data to/from the accumulator

To execute instructions // To perform calculations // by example // To perform logical operations // by example // To store interim results of calculations // Stores/reads/writes data to/from the accumulator

It could have more cores

… increasing the number of FDE cycles/instructions it can perform at the same time

It could have a higher clock speed

… increasing the number of FDE cycles/instructions per second it can perform

printer

computer

priority level

fetch–decode–execute cycle

interrupt queue

higher

interrupt service routine (ISR)

Memory management

Multitasking