OCR GCSE Computer Science Past Papers & Mark Schemes

Programming questions account for around 40% of Paper 2. The single highest-yield habit is to write 100 lines of OCR-pseudocode programs per week from the start of Year 11. The pseudocode looks Python-like but has subtle differences (uppercase keywords, explicit variable casts, USERINPUT). Examiner reports show that candidates who use Python syntax in pseudocode answers lose marks. For algorithm questions, learn three sorting algorithms (bubble, merge, insertion) and two search algorithms (linear, binary). For each, you must be able to: trace the algorithm on a given list, identify the time complexity, and describe in one sentence when each algorithm is appropriate. Boolean logic and truth tables appear on every paper. Practise drawing logic gate circuits from Boolean expressions and vice versa. AND, OR, NOT, XOR are core; some questions chain three gates. Network-protocol questions reward precise terminology. Know the OSI/TCP-IP layer mappings (HTTP/HTTPS at the application layer, TCP/UDP at the transport, IP at the network), the difference between a switch and a router, and the role of DNS and DHCP. For data representation, drill binary-to-hex-to-decimal conversion until it is automatic. Understand the floor of binary addition (carry-1) and overflow.