IGCSE Computer Science

Binary, denary and hexadecimal, and how text, sound and images are stored.

• Binary, denary and hexadecimal conversion
• Binary addition and overflow
• Logical binary shifts
• Two's complement
• Text: ASCII and Unicode
• Sound and images: sample rate, resolution and colour depth
• Data storage and file size calculations
• Lossy and lossless compression

• Binary Numbers and Bitwise Operators

How data is sent, checked and protected.

• Packets and packet switching
• Serial and parallel transmission, simplex, half-duplex and full-duplex
• USB
• Error detection: parity check, checksum, echo check and check digit
• Automatic repeat query (ARQ)
• Symmetric and asymmetric encryption

Covered in 1:1 mentoring sessions

The CPU and the devices around it.

• The CPU and the fetch-decode-execute cycle
• Core, cache and clock speed
• Instruction sets and embedded systems
• Input and output devices
• Sensors
• Primary and secondary storage, including virtual memory and cloud storage
• Network interface cards, MAC addresses and IP addresses

Covered in 1:1 mentoring sessions

Operating systems, languages and translators.

• System software and application software
• Operating system functions
• Interrupts
• High-level and low-level languages
• Compilers and interpreters
• Integrated development environments (IDEs)

Covered in 1:1 mentoring sessions

The web, protocols and cyber security.

• The internet and the World Wide Web
• URLs, web servers, DNS and web browsers
• HTTP and HTTPS
• Cookies
• Digital currency and blockchain
• Cyber security threats: malware, phishing and brute force
• Prevention: firewalls, anti-malware, passwords and two-step verification

• HTTP vs HTTPS, ports and common protocols

Robotics, automated systems and artificial intelligence.

• Automated systems and their sensors
• Robotics
• Artificial intelligence and machine learning
• Benefits and risks of emerging technologies
• Ethical issues

Covered in 1:1 mentoring sessions

The program development life cycle, flowcharts, pseudocode, trace tables and testing.

• Program development life cycle
• Computer systems, sub-systems and decomposition
• Structure diagrams, flowcharts and pseudocode
• Standard methods: linear search, bubble sort, totalling, counting, maximum, minimum and average
• Validation and verification
• Test data: normal, abnormal, extreme and boundary
• Trace tables
• Identifying errors and suggesting corrections

• Working Examples by Hand and Finding Edge Cases
• Tracing code by hand and with print
• Bubble, Selection and Insertion Sort

Variables, selection, iteration, procedures, functions, arrays and files.

• Variables, constants and basic data types
• Input and output
• IF and CASE statements
• Count-controlled, pre-condition and post-condition loops
• String handling
• Arithmetic, logical and Boolean operators
• Procedures, functions and parameters
• Local and global variables
• One-dimensional and two-dimensional arrays
• Reading from and writing to text files

• The if and if-else Statements
• The for Loop and range()
• Defining and Calling Functions
• Nested Lists and Matrices

Single-table databases, primary keys and SQL.

• Fields, records and data types
• Primary keys
• SQL: SELECT, FROM, WHERE and ORDER BY
• SQL functions: SUM and COUNT
• Reading and writing queries on a table

• Primary keys
• ORDER BY and LIMIT
• COUNT, SUM, AVG, MIN and MAX

Logic gates, truth tables, logic circuits and expressions.

• NOT, AND, OR, NAND, NOR and XOR gates
• Truth tables
• Logic circuits from expressions
• Logic circuits from scenarios
• Writing logic expressions from circuits

• Logical and Membership Operators

Both papers, command words and a revision plan.

• Structure of Paper 1 and Paper 2
• Command words: state, describe and explain
• Cambridge pseudocode layout and keywords
• Planning the scenario question
• Past-paper style practice
• A revision calendar

Covered in 1:1 mentoring sessions