OCR GCSE Computer Science (J277) is a popular choice for secondary schools across England. The specification is assessed entirely through two written papers — no coursework or programming project is required. This page collects the best free revision resources for both components, with interactive tools, exam-style practice questions and tutoring support built around the J277 specification.
All tools are completely free — no account required. They work alongside your classroom teaching and are designed around the OCR GCSE specification.
These questions are in the style of OCR GCSE exam questions. Use the hint to check your approach, then visit the Question Bank for hundreds more with mark schemes.
Describe the role of the operating system in managing memory.
Hint: Award marks for: allocates memory to processes/programs [1]; keeps track of which areas of memory are in use [1]; deallocates memory when a process ends [1]; may use virtual memory to extend available RAM using storage [1]. Any 3.
A network uses a star topology. State two advantages of a star topology over a bus topology.
Hint: E.g. If one cable fails, other devices are unaffected (bus topology fails entirely) [1]. Easier to add new devices without disrupting the network [1]. Performance does not degrade as much when multiple devices communicate [1]. Any 2.
Convert the hexadecimal value B7 to denary. Show your working.
Hint: B = 11, 7 = 7. B7 = (11 × 16) + (7 × 1) = 176 + 7 = 183. Mark for correct method [1] and correct answer [1].
Write pseudocode for a bubble sort that sorts the following array into ascending order: [6, 3, 8, 2, 9].
Hint: Must show nested loop [1], comparison of adjacent elements [1], swap logic [1], and early termination condition (no swap in a pass) [1]. OCR pseudocode uses FOR/WHILE loops and array[index] notation.
Explain what is meant by "validation" and give one example of a validation rule for a date of birth field.
Hint: Validation: automated check that data is reasonable/acceptable [1], performed before data is accepted/stored [1]. Example: range check — date of birth must be between 01/01/1900 and today's date [1]. Or: format check — must be DD/MM/YYYY [1].
Want hundreds more practice questions?
The Question Bank has exam-style questions with worked mark schemes — all free.
Gareth is an experienced Computer Science teacher and tutor specialising in OCR GCSE and A Level. Sessions cover the topics you find most difficult — from understanding the FDE cycle to debugging your NEA code. Lessons are online via video call with a shared digital workspace.
OCR J277 does not mandate a specific programming language. Python is the most popular choice, but OCR's pseudocode reference language is used in the question papers. Answers in any high-level language are accepted in Component 02 written questions.
Component 01 (Computer Systems) and Component 02 (Computational Thinking, Algorithms and Programming) are each 1 hour 30 minutes and worth 80 marks, totalling 100% of the GCSE. There is no coursework component in J277.
The content is very similar — both cover computer systems, networks, algorithms and programming. Key differences: OCR J277 uses its own pseudocode style (slightly different syntax to AQA's), and OCR's question style tends to include more scenario-based questions. OCR also removed the programming project from J277 — it is entirely written exam.
Frequently tested: the von Neumann architecture and FDE cycle, primary and secondary memory, network topologies (star, mesh, bus), network protocols (TCP/IP, HTTP, FTP), types of malware and defences, and the role of the operating system.
Common topics: writing and tracing pseudocode and Python, sorting algorithms (bubble, merge, insertion) with trace tables, binary search, computational thinking concepts (abstraction, decomposition), Boolean logic truth tables, and data validation/verification.
No. The OCR J277 specification (introduced 2020) is 100% examined — there is no programming project or coursework component. This differs from the older OCR J276 specification which did include a programming project.