Tyneside Academy · first GCSE · OCR J277

Computer Science

Lewis sits Computer Science first. Course home for OCR J277: every unit is a full open lesson with teaching, exercises, and a self-check quiz. No locks, no required order.

Lewis sits Computer Science first. This page is the course home — every official topic on the map, each one a door into a full lesson with teaching, exercises, and a self-check quiz.

Nothing is locked. There is no required order, no score gate, no “complete this to continue”. Jump to Paper 2 before Paper 1 if you want. Skip a quiz. Reveal a model answer. Sit a mock exam when you want a score — or never. Come back later.

The map follows Cambridge OCR J277 (GCSE 9–1). If the entry is a different board later, the ideas barely move; we retag the codes.

Official specification: OCR J277.

2 Written papers

11 Units

26 Spec points

16 Open lessons

J277/01 · 50% · 80 marks · 1 hour 30 minutes · no calculator

Computer systems

How computers actually work — the box, the data, the network, the rules.

1.1

Systems architecture

What the processor is, how it runs a program, and computers that live inside other things.

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1.1.1 Open lesson

Architecture of the CPU

Purpose of the CPU. Von Neumann. ALU, CU, cache, registers (PC, ACC, MAR, MDR, CIR). Fetch–execute cycle, one step at a time.

1.1.2 Open lesson

CPU performance

Clock speed, cache size, number of cores — what each one changes, and the usual trade-offs.

1.1.3 Open lesson

Embedded systems

A computer built into another device. Examples, typical characteristics, why you would (and would not) use one.

1.2

Memory and storage

Where data lives while a program runs, where it lives when the power is off, and how we measure and encode it.

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1.2.1 Open lesson

Primary storage

RAM vs ROM. Virtual memory. Why a computer needs each, and what happens when RAM runs out.

1.2.2 Open lesson

Secondary storage

Magnetic, solid state, optical. Capacity, speed, cost, portability, durability. How to choose for a given job.

1.2.3 Open lesson

Units

Bit, nibble, byte, through to petabyte. Why 1,024 not 1,000. File-size and capacity calculations — show working.

1.2.4 Open lesson

Data storage

Numbers (binary, denary, hex, addition, overflow, shifts). Characters (ASCII, Unicode). Images (pixels, colour depth, metadata). Sound (sample rate, bit depth).

1.2.5 Open lesson

Compression

Why we compress. Lossy vs lossless. When each is the right call, and what you give up.

1.3

Computer networks, connections and protocols

How machines talk — local, worldwide, wired, wireless, and the rules they agree on.

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1.3.1 Open lesson

Networks and topologies

LAN vs WAN. Hardware (NIC, switch, router, WAP). Star and mesh. Internet, DNS, hosting, the cloud, web servers vs clients.

1.3.2 Open lesson

Wired and wireless, protocols and layers

Ethernet, Wi-Fi, Bluetooth. IP vs MAC. Standards. Common protocols (TCP/IP, HTTP, HTTPS, FTP, POP, IMAP, SMTP). Layers — what a layer is for.

1.4

Network security

How systems get attacked, and what you actually do about it.

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1.4.1 Open lesson

Threats to computer systems and networks

Malware, social engineering, phishing, brute force, DoS, data interception, SQL injection. What each one is trying to do.

1.4.2 Open lesson

Identifying and preventing vulnerabilities

Penetration testing. Anti-malware, firewalls, user access levels, passwords, encryption, physical security. Match the defence to the threat.

1.5

Systems software

The software that runs the machine, and the little tools that keep it usable.

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1.5.1 Open lesson

Operating systems

User interface, memory management, multitasking, peripheral management, user management, file management. What the OS is doing while you are not looking.

1.5.2 Open lesson

Utility software

Encryption software, defragmentation, compression. Extra jobs the OS may not do on its own.

1.6

Ethical, legal, cultural and environmental impacts

Technology is not just circuits. People, law, culture, and the planet get a vote.

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1.6.1 Open lesson

Impacts of digital technology

Stakeholders, privacy, access, work, culture, environment. Legislation you must be able to name and apply — Data Protection (UK GDPR), Computer Misuse, Copyright. Open source vs proprietary licences. Extended-response practice lives here.

J277/02 · 50% · 80 marks · 1 hour 30 minutes · no calculator

Computational thinking, algorithms and programming

Thinking, designing, tracing, and writing programs — including a long programming scenario.

2.1

Algorithms

How you think a problem into steps, write those steps down, and know the famous ones.

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2.1.1 Open lesson

Computational thinking

Abstraction, decomposition, algorithmic thinking. Spot which one a question is asking for.

2.1.2 Open lesson

Designing, creating and refining algorithms

Inputs, processes, outputs. Structure diagrams. Pseudocode and flowcharts. Trace tables. Nesting. Find and fix errors. OCR Exam Reference Language.

2.1.3 Open lesson

Searching and sorting algorithms

Linear search, binary search. Bubble sort, insertion sort, merge sort. Be able to step through them, not just name them.

2.2

Programming fundamentals

The language of Paper 2 — constructs, types, and the extra techniques the exam actually uses.

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2.2.1 Open lesson

Programming fundamentals

Variables, constants, operators, inputs, outputs, assignment. Sequence, selection, iteration. Count-controlled and condition-controlled loops. Nesting the three constructs.

2.2.2 Open lesson

Data types

Integer, real, Boolean, character, string. Casting. Why the type matters when the exam tries to trip you.

2.2.3 Open lesson

Additional programming techniques

String handling. Arrays (1D and 2D) and records. Files. Functions and procedures, parameters, return values, scope. SQL. Random numbers.

2.3

Producing robust programs

Code that survives bad input, and tests that actually find the bugs.

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2.3.1 Open lesson

Defensive design

Anticipate misuse. Authentication. Input validation. Maintainable code — naming, indentation, comments.

2.3.2 Open lesson

Testing

Iterative vs final/terminal testing. Syntax errors vs logic errors. Test data — normal, boundary, invalid. A test plan that would convince a marker.

2.4

Boolean logic

AND, OR, NOT — on paper, in a truth table, and as a diagram.

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2.4.1 Open lesson

Boolean logic

Operators, truth tables, combining gates, drawing and reading logic diagrams. Same ideas as in a program, different picture.

2.5

Programming languages and IDEs

Why we do not write everything in binary, and what the editor is doing for you.

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2.5.1 Open lesson

Languages

High-level vs low-level. Translators. Compiler vs interpreter — characteristics and when each is used.

2.5.2 Open lesson

The IDE

Editors, error diagnostics, run-time environment, translators. What an IDE gives you that a plain text file does not.

Required practice · not a third paper

Practical programming

Not a third exam paper — but the spec requires real coding hours, and Paper 2 will punish anyone who has only read about it.

OCR expects programming experience (Python is the usual language). Lewis already ships games; this strand is exam-shaped Python and Exam Reference Language, not another arcade.

Open the full programming lesson →

py-core Open lesson