IGCSE Computer Science (0478)

Number systems

• 1.1 — Why Computers Use Binary to Represent Data
• 1.2 — The Denary Number System and Place Value
• 1.3 — The Binary Number System and Place Value
• 1.4 — Converting Positive Denary Integers to Binary
• 1.5 — Converting Positive Binary Integers to Denary
• 1.6 — Hexadecimal Digits and Place Value
• 1.7 — Converting Positive Denary Integers to Hexadecimal
• 1.8 — Converting Positive Hexadecimal Integers to Denary
• 1.9 — Converting Positive Binary Integers to Hexadecimal
• 1.10 — Converting Positive Hexadecimal Integers to Binary
• 1.11 — Why Hexadecimal Is Used in Computing
• 1.12 — Adding Two Positive 8-bit Binary Integers and Identifying Overflow
• 1.13 — Performing Logical Left and Right Shifts
• 1.14 — Representing Positive 8-bit Integers in Two's Complement
• 1.15 — Representing and Converting Negative 8-bit Values Using Two's Complement

Text, sound and images

• 2.1 — Why Computers Represent Text Using Binary
• 2.2 — Character Sets and ASCII
• 2.3 — Unicode Compared with ASCII
• 2.4 — How Sound Is Sampled and Represented in Binary
• 2.5 — How Sample Rate Affects Sound Quality and File Size
• 2.6 — How Sample Resolution Affects Sound Quality and File Size
• 2.7 — Pixels, Image Resolution and Digital Image Representation
• 2.8 — Colour Depth and Its Effect on Image Quality and File Size

Data storage and compression

• 3.1 — Bits, Nibbles, Bytes and Larger Storage Units
• 3.2 — Converting Storage Units Using 1024
• 3.3 — Calculating Image File Size from Resolution and Colour Depth
• 3.4 — Calculating Sound File Size from Sample Rate, Sample Resolution and Duration
• 3.5 — Why Data Compression Is Needed
• 3.6 — Lossy and Lossless Compression Compared
• 3.7 — How Run-length Encoding (RLE) Compresses Data

Types and methods of data transmission

• 4.1 — Packet Structure and Packet Switching: Header, Payload, Trailer, Addresses, Packet Numbers and Reassembly
• 4.2 — Serial and Parallel Transmission: Operation and Suitability
• 4.3 — Simplex, Half-duplex and Full-duplex Transmission
• 4.4 — The USB Interface: How It Transmits Data, Benefits and Drawbacks
• 4.5 — Selecting a Suitable Transmission Method for a Scenario

Methods of error detection

• 5.1 — Why Data Is Checked After Transmission: Data Loss, Gain and Change
• 5.2 — Odd and Even Parity Checks
• 5.3 — Parity Byte and Parity Block Checks
• 5.4 — How Checksums Detect Transmission Errors
• 5.5 — How Echo Checking Detects Transmission Errors
• 5.6 — Check Digits in Bar Codes and ISBNs
• 5.7 — Automatic Repeat Query (ARQ): Acknowledgements, Timeout and Retransmission

Encryption

• 6.1 — Why Encryption Is Needed: Plaintext, Ciphertext, Encryption and Decryption
• 6.2 — Symmetric Encryption and the Shared Secret Key
• 6.3 — Asymmetric Encryption: Public and Private Keys, Encryption and Decryption

Computer architecture

• 7.1 — The Role of the Central Processing Unit (CPU) and Microprocessors
• 7.2 — CPU Units and System Buses: ALU, Control Unit, Address, Data and Control Buses
• 7.3 — CPU Registers: PC, MAR, MDR, CIR and ACC
• 7.4 — The Fetch–Decode–Execute (FDE) Cycle
• 7.5 — CPU Performance: Cores, Cache and Clock Speed
• 7.6 — The Purpose and Use of a CPU Instruction Set
• 7.7 — Embedded Systems: Purpose, Characteristics and Examples

Input and output devices

• 8.1 — Input Devices: Keyboards, Optical Mice, Digital Cameras and Microphones
• 8.2 — Optical Readers and Scanners: Bar Codes, QR Codes, 2D Scanners and 3D Scanners
• 8.3 — Touch Screens: Resistive, Capacitive and Infra-red
• 8.4 — Output Devices: Inkjet and Laser Printers, LED/LCD Screens, and LCD/DLP Projectors
• 8.5 — Speakers, 3D Printers and Actuators as Output Devices
• 8.6 — What Sensors Do and Why They Are Used
• 8.7 — Sensors: Acoustic, Accelerometer, Flow, Gas and Humidity
• 8.8 — Sensors: Infra-red, Level, Light, Magnetic Field and Moisture
• 8.9 — Sensors: pH, Pressure, Proximity and Temperature
• 8.10 — Selecting Suitable Input, Output Devices and Sensors for a Scenario

Data storage

• 9.1 — Primary Storage: RAM and ROM and Their Uses
• 9.2 — Secondary Storage and Why It Is Needed
• 9.3 — Magnetic Storage: Platters, Tracks and Sectors
• 9.4 — Optical Storage: Pits, Lands and Lasers
• 9.5 — Solid-state Storage: NAND/NOR Technology and Floating-gate Transistors
• 9.6 — Virtual Memory: Purpose and Operation
• 9.7 — Cloud Storage Compared with Local Storage

Network hardware

• 10.1 — Network Interface Cards (NICs) and MAC Addresses
• 10.2 — MAC Address Structure: Manufacturer Codes, Serial Codes and Hexadecimal
• 10.3 — IP Addresses and Static versus Dynamic Allocation
• 10.4 — IPv4 and IPv6 Compared
• 10.5 — The Role of a Router: Forwarding Data, Assigning IP Addresses and Connecting to the Internet

Types of software and interrupts

• 11.1 — System Software, Utility Software and Application Software
• 11.2 — Operating System Functions: Interface, Files, User Accounts and Application Platform
• 11.3 — Operating System Functions: Memory, Multitasking, Peripherals, Drivers and Security
• 11.4 — Hardware, Firmware, the Bootloader, Operating System and Applications
• 11.5 — Hardware and Software Interrupts: Generation and Examples
• 11.6 — Interrupt Service Routines (ISRs): Handling Interrupts and Their Results

Types of programming language, translators and integrated development environments (IDEs)

• 12.1 — High-level and Low-level Languages: Characteristics, Advantages and Disadvantages
• 12.2 — Assembly Language, Mnemonics and the Assembler
• 12.3 — How a Compiler Translates Code and Reports Errors
• 12.4 — How an Interpreter Translates and Executes Code and Reports Errors
• 12.5 — Comparing Compilers and Interpreters: Uses, Advantages and Disadvantages
• 12.6 — IDE Functions: Code Editor, Runtime Environment and Translator
• 12.7 — IDE Assistance: Diagnostics, Auto-completion, Auto-correction and Prettyprint

The internet and the World Wide Web

• 13.1 — The Internet and the World Wide Web Compared
• 13.2 — URLs and Their Components
• 13.3 — HTTP and HTTPS: Purpose and Differences
• 13.4 — Web Browser Functions and How Browsers Display Retrieved Pages
• 13.5 — Finding and Retrieving a Web Page: DNS, IP Addresses, Web Servers and HTML
• 13.6 — Session and Persistent Cookies

Digital currency

• 14.1 — What Digital Currency Is and How It Is Used
• 14.2 — Blockchain as a Time-stamped Digital Ledger
• 14.3 — How Blockchain Records Track Digital Currency Transactions

Cyber security

• 15.1 — Brute-force Attacks and the Purpose of Cybersecurity
• 15.2 — Malware: Viruses, Worms and Trojan Horses
• 15.3 — Malware: Spyware, Adware and Ransomware
• 15.4 — Data Interception, Hacking and Distributed Denial of Service (DDoS)
• 15.5 — Social Engineering: Phishing and Pharming
• 15.6 — Access Levels and Authentication: Passwords, Biometrics and Two-step Verification
• 15.7 — Anti-malware, Automated Updates, Firewalls and Proxy Servers
• 15.8 — Communication Safety, URL Checking, Privacy Settings and SSL Security Protocol

Automated systems

• 16.1 — The Roles of Sensors, Microprocessors and Actuators
• 16.2 — How an Automated System Processes Input and Produces Output
• 16.3 — Automated Systems in Industry, Transport, Agriculture, Weather, Gaming, Lighting and Science
• 16.4 — Advantages and Disadvantages of Automated Systems in a Given Scenario

Robotics

• 17.1 — What Robotics Is and the Characteristics of a Robot
• 17.2 — Robot Structures, Sensors, Microprocessors, Actuators and Programmability
• 17.3 — Uses of Robots in Industry, Transport, Agriculture, Medicine, Domestic Settings and Entertainment
• 17.4 — Advantages and Disadvantages of Robots in a Given Scenario

Artificial intelligence

• 18.1 — What Artificial Intelligence (AI) Is
• 18.2 — Data and Rules in AI Systems
• 18.3 — Reasoning, Learning and Adaptation in AI Systems
• 18.4 — The Basic Operation and Components of AI Systems
• 18.5 — Expert Systems: Knowledge Base, Rule Base, Inference Engine and Interface
• 18.6 — Machine Learning: Programs Adapting Their Own Processes or Data

Algorithm design and problem-solving

• 19.1 — The Program Development Life Cycle: Analysis, Design, Coding and Testing
• 19.2 — Analysis: Identifying Problem Requirements and Abstraction
• 19.3 — Decomposition: Breaking Problems into Smaller Parts and Sub-systems
• 19.4 — Structure Diagrams for Representing a Solution
• 19.5 — Standard Flowchart Symbols and Representing Input, Process, Output and Storage
• 19.6 — Reading and Constructing Flowcharts for Given Problems
• 19.7 — Reading and Writing Cambridge-style Pseudocode
• 19.8 — Explaining the Purpose and Processes of an Algorithm
• 19.9 — Standard Solution Methods: Totalling and Counting
• 19.10 — Finding Maximum and Minimum Values and Calculating an Average
• 19.11 — The Linear Search Algorithm
• 19.12 — The Bubble Sort Algorithm
• 19.13 — Input Validation: Purpose, Range, Length, Type and Presence Checks
• 19.14 — Input Validation: Format and Check-digit Checks
• 19.15 — Verification Checks and Writing Algorithms to Implement Visual and Double-entry Verification
• 19.16 — Normal, Abnormal, Extreme and Boundary Test Data
• 19.17 — Completing Trace Tables to Dry-run Algorithms
• 19.18 — Identifying and Correcting Errors in Algorithms
• 19.19 — Writing and Amending Algorithms for Given Problems and Scenarios

Programming concepts

• 20.1 — Declaring and Using Variables and Constants
• 20.2 — Basic Data Types: Integer, Real, Char, String and Boolean
• 20.3 — Input and Output in Programs
• 20.4 — Arithmetic Operators, Including MOD and DIV
• 20.5 — Relational and Logical Operators
• 20.6 — Sequence and the Order of Program Statements
• 20.7 — Selection Using IF Statements
• 20.8 — Selection Using CASE Statements
• 20.9 — Count-controlled Iteration Using FOR Loops
• 20.10 — Pre-condition WHILE Loops and Post-condition REPEAT Loops
• 20.11 — Nested Selection and Iteration up to Three Levels
• 20.12 — Totalling and Counting in Programs
• 20.13 — String Handling: LENGTH, SUBSTRING, UCASE and LCASE
• 20.14 — Procedures with and without Parameters
• 20.15 — Functions, Parameters and Return Values
• 20.16 — Local and Global Variables
• 20.17 — Library Routines: ROUND and RANDOM
• 20.18 — Maintainable Programs: Meaningful Identifiers, Comments and Modularity

Arrays

• 21.1 — Array Indexes and Bounds: Starting at Zero or One
• 21.2 — Declaring, Accessing and Updating One-dimensional (1D) Arrays
• 21.3 — Traversing 1D Arrays Using Iteration
• 21.4 — Declaring and Accessing Two-dimensional (2D) Arrays
• 21.5 — Using Nested Iteration with 2D Arrays

File handling

• 22.1 — Why Programs Use Files and How to Open and Close Them
• 22.2 — Reading and Writing Single Items of Data in a File
• 22.3 — Reading and Writing a Line of Text in a File

Databases

• 23.1 — Tables, Records and Fields
• 23.2 — Defining a Single-table Database from Given Requirements
• 23.3 — Database Data Types: Date/time, Text/Alphanumeric, Character, Boolean, Integer and Real
• 23.4 — Validating Data in a Database Table
• 23.5 — Primary Keys and Uniquely Identifying Records
• 23.6 — SQL SELECT and FROM: Choosing Fields
• 23.7 — SQL WHERE with AND and OR: Filtering Records
• 23.8 — SQL ORDER BY: Sorting Ascending and Descending
• 23.9 — SQL SUM and COUNT
• 23.10 — Predicting the Output of SQL Queries for a Given Table

Logic Gate Symbols and Functions

• 24.1 — The NOT Gate — Symbol, Function and Truth Table
• 24.2 — AND and OR Gates — Symbols, Functions and Truth Tables
• 24.3 — NAND and NOR Gates — Symbols, Functions and Truth Tables
• 24.4 — XOR (EOR) Gate — Function, Truth Table and Comparison with OR

Truth Tables: Input Combinations and Output Calculation

• 25.1 — Listing Binary Input Combinations and Setting Up Truth Tables
• 25.2 — Completing Truth Tables from Logic Expressions
• 25.3 — Completing Truth Tables from Logic Circuits
• 25.4 — Completing Truth Tables from Problem Statements

Writing Logic Expressions

• 26.1 — Writing Logic Expressions from Logic Circuits
• 26.2 — Writing Logic Expressions from Truth Tables
• 26.3 — Translating Problem Statements into Logic Expressions

Designing and Checking Logic Circuits

• 27.1 — Drawing Logic Circuits from Logic Expressions
• 27.2 — Drawing Logic Circuits from Truth Tables
• 27.3 — Drawing Logic Circuits from Problem Statements
• 27.4 — Checking a Logic Solution Against Its Truth Table and Requirements

Paper 2 Scenario Practice

• 25.1 — Paper 2 Practice: Planning, Writing and Checking the 15-mark Unseen Scenario Solution