A Level Computer Science 9618 lectures
27 short lectures, one for each part of the syllabus, in the order it is taught. Each one teaches a topic on the board in a few minutes. The teaching part is free to watch; a free account opens the rest of every lecture: worked examples, practice questions and real past-paper questions answered.
Chapter 1 Information representation
- Binary, denary, hexadecimal, BCD and prefixesA light switch is on or off.6 min
- Binary addition, subtraction, overflow and two’s complementYou add denary numbers in columns, carrying when a column passes nine.7 min
- Character sets, run-length encoding and compressionWhen you press the letter A on a keyboard, the computer does not store a letter.6 min
- Bitmap images, vector graphics and soundA photo is a grid of tiny coloured dots.6 min
Chapter 2 Communication
- Bit streaming, client-server, peer-to-peer and cloud computingWhen you watch a live video call, the picture appears long before the whole call has been sent.6 min
- Ethernet, CSMA/CD, LAN hardware and IP addressesA room of people all talking at once is noise.7 min
- LAN, WAN, topologies and wired and wireless networksA network joining the computers in one room is small and private.7 min
Chapter 3 Hardware
Chapter 4 Processor fundamentals
- The processor, registers, buses and the fetch-execute cycleEvery program you have ever run is, to the processor, a long list of instructions.6 min
- Binary shifts and bit manipulationIn denary, to multiply by ten you add a zero: slide every digit one place left.6 min
- Instruction groups, addressing modes, the two-pass assembler, tracing, CPU performance and portsMachine code is just binary.7 min
Chapter 5 System software
Chapter 6 Security, privacy and data integrity
Chapter 7 Ethics and ownership
Chapter 8 Databases
Chapter 9 Algorithm design and problem-solving
Chapter 10 Data types and structures
Chapter 11 Programming
- Pseudocode constructs: IF, CASE, records and arraysEvery algorithm in Paper 2 is built from three ideas.6 min
- Choosing data types and loops, evaluating expressions, and decompositionA postcode, a price, a yes or no.5 min
- Finding errors in statements, following algorithms, good practice and identifier tablesA computer does exactly what the code says, not what you meant.6 min
Chapter 12 Software development
Also for A Level Computer Science 9618
Which topics come up most in A Level Computer Science 9618 past papers, counted from every paper since 2004: Paper 1 topic frequency, Paper 2 topic frequency.