A-Level Computer Science Revision Notes

17 free revision notes covering every main A-Level Computer Science topic. No account needed.

A-Level Computer Science is a significant step up from GCSE, and the jump is conceptual rather than merely harder. GCSE asks what a component does; A-Level asks how it works and why it was designed that way. Theory of computation, Boolean algebra and data structures have no real GCSE equivalent at all.

Programming is where the grade is usually won or lost, and it cannot be revised by reading. The non-exam assessment carries substantial weight and rewards steady work over a long period far more than a concentrated effort near the deadline.

For the written papers, the recurring demand is precision about mechanism. Knowing that a stack is last-in-first-out is a GCSE-level answer; being able to trace push and pop operations, explain how a stack frame supports recursion, and say what happens on overflow is an A-Level one.

These notes cover architecture, data structures, algorithms, networks, databases, Boolean algebra and theory of computation, with worked examples throughout.

Algorithms

Big-O Time Complexity Graph and Tree Traversals Dijkstra's Shortest Path Algorithm

Boolean Algebra

Boolean Algebra and Logic Simplification

Compilation

Translators and the Stages of Compilation

Computer Architecture

Assembly Language and the Little Man Computer

Computer Security

Encryption and Hashing

Data Representation

Floating Point Numbers

Data Structures

Stacks and Queues Trees and Graphs Hash Tables and Dictionaries

Databases

Normalisation and SQL

Networks

The TCP/IP Stack and Protocols

Programming

Recursion Object-Oriented Programming Programming Paradigms

Theory of Computation

Finite State Machines

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