OCR J277 Computer Science Notes

Paper 1: Computer Systems

• 1.1 Systems Architecture
• CPU Components: ALU, Control Unit (CU), Registers
• Fetch-Decode-Execute Cycle
• Von Neumann Architecture: MAR, MDR, Program Counter, Accumulator
• Embedded Systems: Purpose-built computers for a specific task
• 1.2 Memory and Storage
• Primary Storage: RAM (volatile), ROM (non-volatile)
• Secondary Storage: HDD, SSD, Optical Media
• Units of Storage: Bit, Byte, KB, MB, GB, TB
• Volatility and speed differences between storage types
• 1.3 Computer Networks, Connections, and Protocols
• Network Types: LAN, WAN
• Network Topologies: Star, Bus, Ring
• Network Hardware: Routers, Switches, Hubs, NICs
• Protocols: TCP/IP, HTTP, HTTPS, FTP, SMTP, POP3
• 1.4 Network Security
• Threats: Malware (virus, worm, Trojan), Phishing, Social Engineering
• Prevention: Firewalls, Encryption, Anti-virus software, Strong passwords
• Ethical & Legal considerations: Data Protection Act, Computer Misuse Act
• 1.5 Systems Software
• Operating Systems: Functions, types, managing hardware/software
• Utility Software: Backup, Compression, Defragmentation, Anti-virus
• 1.6 Ethical, Legal, Cultural, and Environmental Impacts
• Data Protection, Intellectual Property, Privacy
• Environmental impact of electronic waste and energy usage

Paper 2: Computational Thinking, Algorithms, and Programming

• 2.1 Algorithms
• Computational Thinking: Decomposition, Abstraction, Pattern Recognition, Algorithm Design
• Searching Algorithms: Linear, Binary
• Sorting Algorithms: Bubble, Merge, Insertion
• Pseudocode and Flowcharts
• 2.2 Programming Fundamentals
• Data Types: Integer, Boolean, String, Float
• Variables, Constants
• Operators: Arithmetic, Relational, Logical
• Control Structures: IF, ELSE, SWITCH, Loops (FOR, WHILE)
• 2.3 Producing Robust Programs
• Defensive Design: Input Validation, Error Handling
• Testing: Unit Testing, Integration Testing
• Purpose of Comments and Readable Code
• 2.4 Boolean Logic
• Logic Gates: AND, OR, NOT, NAND, NOR, XOR
• Truth Tables
• Combining Logic Gates
• 2.5 Programming Languages and IDEs
• High-level vs Low-level Languages
• Compilers, Interpreters, Assemblers
• Integrated Development Environments (IDEs): Features, Debugging Tools