OCR A-Level Computer Science Lessons

With ‘Paid Membership’ you will have access to the following lesson presentations and any accompanying activity sheets:

…try the links to see some SAMPLE material!


1.1.1 CPU Structure /Function CPU Structure and Function

CPU Performance

1.1.2 Processor Types  Processor Types
1.1.3 I/O and Storage Input and Output Devices

Primary Memory and Secondary Storage

1.2.1 System Software Operating Systems 1

Operating Systems 2 *Sample

1.2.2 Applications Application Software VS Utility Software

Compilers, Interpreters and Assemblers + Bytecode

Stages of Compilation and Linkers & Loaders

1.2.3 Software Development Comparing Development Methodologies
1.2.4 Languages Procedural Programming – Program Flow
Procedural Programming – Variables, Constants and Types
Procedural Programming – Nesting, Procedures and Functions
Procedural Programming – Arithmetic, Boolean and Assignment Operators
Procedural Programming – String Handling
Procedural Programming – File OperationsAssembly Language – Lesson 1
Assembly Language – Lesson 2Introduction to Object Orientated Programming

OOP Starter Questions
OOP Python – Instantiation and Understanding SELF

OOP Python – Inheritance
OOP Python Inheritance Challenges

OOP Python – Encapsulation and Polymorphism
Summary Exercises

1.3.1 Compression, Encryption and Hashing Compression, Encryption and Hashing
1.3.2 Databases Relational Databases


1.3.3 Networks Network Types and Network Hardware

The Internet, the WWW & Virtual Networks

Internet Communications

Internet Threats and Security

1.3.4 Web Technologies HTML




Search Engine Indexing and the Page Rank Algorithm

Server Side and Client Side Processing

1.4.1 Data Types Positive Binary and Hexadecimal Integers

Negative Binary Numbers and Subtraction *Sample

Fixed Point Binary Numbers

ASCII and Unicode

Floating Point Binary Numbers

Floating Point Binary Arithmetic

1.4.2 Data Structures Arrays (of up to 3 dimensions), records, lists, tuples

Stacks and Queues

Linked Lists


Trees and Binary Trees

Hashing and Hash Tables

1.4.3 Boolean Algebra Logic Gates, Truth Tables and Basic Boolean Algebra

Logic Gates and Karnaugh Maps

Simplifying Boolean Algebra

Adders and D-Type Flip-Flops

D-Type Flip-Flops

1.5.1 Legislation  Legislation
1.5.2 Issues Computing Issues
2.1 Computational Thinking  Computational Thinking

Thinking Abstractly

Thinking Ahead

Thinking Procedurally

Thinking Logically

2.2.1 Programming Techniques  Sequence, Selection and Iteration


Global and Local Variables and Modularity

Functions and procedures, parameter passing by value and by reference

Use of an IDE to develop and debug a program

Object Orientated Programming

2.2.3 Development Methods  Comparing Development Methodologies

Writing and Following Algorithms

Different Testing Strategies and Methods

2.2.4 Computational Methods  Computational Methods (Part 1)

Computational Methods (Part 2)

2.3 Algorithms  Algorithm Complexity & Big-O Notation

Stacks and Queues and their implementations

Linked Lists & their Algorithms

Trees and Binary Trees & their Algorithms

Graphs & their traversals

Bubble and Insertion Sort Algorithms

Merge and Quick Sort Algorithms

Linear and Binary Search Algorithms

Dijkstra’s Shortest Path Algorithm

A-Star Algorithm

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