Data representation
Number systems, binary & hexadecimal, two's complement, character/sound/image encoding, units of storage and data compression.
Number Systems & Binary
Why computers use binary, and converting binary ↔ denary.
IG-L1-02Denary → Binary & Hexadecimal
Converting both ways; nibbles and the uses of hex.
IG-L1-03Binary Addition, Shifts & Two's Complement
8-bit addition & overflow, logical shifts, negative numbers.
Character Sets, Sound & Images
ASCII/Unicode; sampling; resolution & colour depth.
IG-L1-05Storage Units & File-Size Calculations
KiB/MiB/GiB and image & sound file sizes.
IG-L1-06Data Compression — Lossy, Lossless & RLE
Why we compress, and run-length encoding worked through.
Data transmission
Packets & packet switching, serial/parallel & duplex modes, error detection (parity, checksum, check digits, ARQ) and encryption.
Data Packets & Packet Switching
Packet structure (header/payload/trailer) and how routers route them.
IG-L2-02Serial, Parallel & Duplex Transmission
Serial vs parallel, simplex/half/full-duplex, and USB.
Error Detection — Parity & Checksum
Parity checks, parity blocks, checksum and echo check.
IG-L2-04Check Digits & ARQ
ISBN-13 check digits and Automatic Repeat reQuests.
IG-L2-05Encryption — Symmetric & Asymmetric
Plaintext/ciphertext, shared keys and public/private key pairs.
Hardware
The CPU and fetch–decode–execute cycle, performance and embedded systems, every input and output device and sensor, primary/secondary/virtual/cloud storage, and network hardware.
The CPU & Von Neumann Architecture
CU, ALU, registers, buses; reading and writing memory with the MAR and MDR.
IG-L3-02The Fetch–Decode–Execute Cycle
Register-by-register trace of the cycle; instruction sets, opcodes and operands.
IG-L3-03CPU Performance & Embedded Systems
Clock, cache, cores, overclocking; microcontrollers, SoCs and embedded devices.
Input & Output Devices
The device map; barcodes, the checkout, stock control and QR codes.
IG-L3-07Digital Cameras, Keyboards, Microphones & Mice
CCD + ADC, key presses to ASCII, microphones and optical mice.
IG-L3-082D & 3D Scanners and Touch Screens
Flatbed scanning, OCR, CT slices; capacitive, infrared and resistive screens.
IG-L3-09Actuators, Projectors & Printers
Solenoids, DLP vs LCD projectors, inkjet, laser and 3D printers.
IG-L3-10LED, LCD & OLED Screens and Loudspeakers
True LED vs LED-backlit LCD, OLED layers, DAC → amplifier → speaker.
IG-L3-11Sensors in Monitoring & Control
All 14 sensors, ADC/DAC, feedback, and monitoring vs control scenarios.
Primary & Secondary Storage
RAM/ROM, DRAM/SRAM; magnetic, solid-state and optical storage.
IG-L3-12Virtual Memory & Cloud Storage
Swap space, paging, thrashing; public, private and hybrid cloud.
IG-L3-06Network Hardware
NIC, MAC (UAA/LAA), IPv4/IPv6, static vs dynamic IP, DHCP, routers.
Software
System and application software, what the operating system does, firmware and booting, interrupts and buffers, high- and low-level languages, translators and IDEs.
System Software & Application Software
The software layers; sorting programs into system or application software, with reasons
IG-L4-02Utility Programs & Device Drivers
Anti-virus, defragmentation, back-up, security, screensavers and device drivers
IG-L4-03The Operating System: Interface, Memory & Security
The OS role; CLI vs GUI (WIMP, post-WIMP); memory management and security management
IG-L4-04The Operating System: Files, Peripherals & Multitasking
Printer queues and buffers, file management, time-sliced multitasking, user accounts
Running Applications: Hardware, Firmware & the OS
How the four layers depend on each other, BIOS firmware, booting up, CMOS settings
IG-L4-06Interrupts & Buffers
Hardware and software interrupts, how an ISR is run, buffers and interrupts when printing
High-Level & Low-Level Languages
Pros and cons of each; machine code, assembly mnemonics, assembly to binary and hex
IG-L4-08Translators: Compilers, Interpreters & Assemblers
How each translator works and reports errors; pros and cons; picking one for a scenario
IG-L4-09Integrated Development Environments (IDEs)
IDE features, and finding a logic error with breakpoints and single-stepping
The internet and its uses
How the internet and web work, how digital currency is secured, and every cyber threat and defence Cambridge examines.
The Internet, the World Wide Web, URLs & HTTP(S)
Internet vs WWW, the parts of a URL, and how HTTP and HTTPS transfer pages
IG-L5-02Web Browsers & Finding Web Pages (DNS)
Browser functions, and how the DNS, IP addresses and web servers deliver a page
IG-L5-03Cookies — Session & Persistent
What cookies store, session vs persistent, and how websites use them
Digital Currency & Blockchain
Digital vs fiat money, cryptocurrency, and how hashed blocks stop tampering
Brute Force, Data Interception, DDoS & Hacking
Password cracking, packet sniffing, wardriving, DDoS floods and hacking
IG-L5-06Malware — Six Types
Virus, worm, Trojan horse, spyware, adware and ransomware compared
IG-L5-07Phishing, Pharming & Social Engineering
Fake emails, DNS cache poisoning, and manipulation through fear, curiosity and trust
IG-L5-08Access Levels, Anti-Malware & Authentication
Access rights, anti-spyware, strong passwords, biometrics and two-step verification
IG-L5-09Updates, Checking Emails & URLs, Firewalls
Security patches, spotting scam emails and typo squatting, and what firewalls do
IG-L5-10Proxy Servers, Privacy Settings & SSL
Proxies and caching, privacy controls, and the SSL certificate process
Automated and emerging technologies
How sensors, microprocessors and actuators automate real systems, what makes a robot and where robots work, and how expert systems and machine learning simulate intelligence.
Sensors, Microprocessors & Actuators in Industry
The sensor–processor–actuator control loop in industry; pros and cons
IG-L6-02Automated Systems in Transport & Agriculture
Self-parking, adaptive cruise control, autopilot, train signals and automatic irrigation
IG-L6-03Automated Systems in Weather, Gaming, Lighting & Science
Weather stations, motion-sensing games, smart lighting, automated labs
What Is a Robot?
Robotics, the three robot characteristics, end-effectors, independent vs dependent robots
IG-L6-05Robots in Industry & Transport
Programming industrial robots; driverless cars, trains and aircraft with pros and cons
IG-L6-06Robots in Agriculture, Medicine, the Home & Entertainment
Harvesting, weeding, drones, surgery, home robots and robots in film
What Is Artificial Intelligence?
AI defined; data + rules, reasoning, learning; narrow, general and strong AI
IG-L6-08Expert Systems
Knowledge base, rules base, inference engine, interface; diagnosis; setting one up
IG-L6-09Machine Learning
Training on data; search engines, spam filters, recommendations, fraud detection
Algorithm design & problem solving
Design, write, test and correct algorithms with structure diagrams, flowcharts, pseudocode and Python, using standard methods, validation and trace tables.
The Program Development Life Cycle
Analysis, design, coding, testing; abstraction, decomposition, iterative testing
IG-L7-02Sub-systems, Decomposition & Structure Diagrams
Top-down design, inputs/processes/outputs/storage, drawing structure diagrams
IG-L7-03Flowcharts
The standard symbols, decisions for selection and loops, flowchart to pseudocode
IG-L7-04Pseudocode: Assignment & Selection
Assignment with ←, operators, IF/ELSE, nested IF and CASE OF … OTHERWISE
IG-L7-05Pseudocode: Iteration & the Purpose of an Algorithm
FOR, REPEAT and WHILE loops, input/output, explaining what an algorithm does
Totalling, Counting, Max, Min & Average
Running totals, counting up and down, two ways to find max/min, the mean
IG-L7-07Linear Search & Bubble Sort
Search with a Found flag; bubble sort passes, swaps and the no-swap stop
Validation & Verification
Range, length, type, presence, format, check digit; double entry, visual check
IG-L7-09Choosing Test Data
Normal, abnormal, extreme and boundary data with expected results; test plans
IG-L7-10Trace Tables & Correcting Errors
Dry runs, full trace tables, finding and fixing errors in algorithms
IG-L7-11Writing & Amending Algorithms
A step-by-step method, a full worked algorithm, amending and nested loops
Programming
Writing real programs in Cambridge pseudocode and Python — data types, the three constructs, subroutines, arrays and files.
Variables, Constants & Data Types
Named stores, DECLARE/CONSTANT, and choosing INTEGER, REAL, CHAR, STRING or BOOLEAN
IG-L8-02Input, Output & Sequence
Prompts, casting input, messages on output, and fixing a wrong-order algorithm
IG-L8-03Selection — IF and CASE
IF…THEN…ELSE…ENDIF and CASE OF…OTHERWISE, with Python if/elif/else
IG-L8-04Iteration — Three Types of Loop
FOR…NEXT (with STEP), WHILE…DO…ENDWHILE and REPEAT…UNTIL, traced
Totalling, Counting & String Handling
Running totals and counts; LENGTH, SUBSTRING, UCASE, LCASE vs Python
IG-L8-06Arithmetic, Logical & Boolean Operators
+ - * / ^ MOD DIV, comparison operators, and AND/OR/NOT in conditions
IG-L8-07Nested Statements
IF inside IF, loops inside loops, and tracing a nested algorithm
IG-L8-08Procedures, Functions & Parameters
PROCEDURE/CALL, FUNCTION…RETURNS…RETURN, and arguments vs parameters
IG-L8-09Scope, Library Routines & Maintainable Programs
Local vs global; MOD, DIV, ROUND, RANDOM; names, modules and comments
One- and Two-Dimensional Arrays
Declaring, indexing, and filling or reading arrays with loops and nested loops
IG-L8-11File Handling
Why files; OPENFILE, READFILE, WRITEFILE, CLOSEFILE; keeping data between runs
Databases
Single-table databases: records, fields, data types and primary keys, then SQL queries with SELECT, WHERE, ORDER BY, SUM and COUNT.
Single-Table Databases: Tables, Records & Fields
What a database is, why use one, records vs fields, and validation inside a table
IG-L9-02Data Types & Primary Keys
The six data types, choosing one per field, and picking or adding a primary key
SQL: SELECT, FROM, WHERE & ORDER BY
Build queries clause by clause; comparison operators, SELECT *, ASC/DESC sorting
IG-L9-04SQL Conditions: AND, OR, NOT, BETWEEN, LIKE & IN
Combine and pattern-match conditions, and why brackets change the result
IG-L9-05SQL: SUM & COUNT
Total a numeric field or count matching records — and tell which one a question wants
Designing a Single-Table Database
Define a table from requirements, choose its key, then read and complete SQL scripts
Boolean logic
The six logic gates, then moving between circuits, logic expressions, truth tables and written problems, as Cambridge Paper 2 asks.
Logic Gates & Truth Tables: NOT, AND, OR
What gates and truth tables are, 2ⁿ rows in counting order, and NOT, AND, OR
IG-L10-02NAND, NOR & XOR Gates
The inverted and exclusive gates, all six side by side, naming a gate from its table
Truth Tables from Logic Circuits
Junction dots, one working column per gate, and tracing a row through a circuit
IG-L10-04Logic Expressions & Circuits
Writing an expression from a circuit, and drawing a circuit from an expression
IG-L10-05From a Truth Table to an Expression & Circuit
Turning the rows where X = 1 into an expression and a circuit
IG-L10-06Logic Circuits from Problem Statements
Reading the parameter table, splitting conditions at OR, then cross-checking