AS Computer Science
Taught in this order — Computer-Science-Syllabus-short.tex — Syllabus Overview in Teaching Order (2026–2027)
1Information representation weeks 1–2 Start unit ›
1.1 Data Representation all covered 11/11 sheet questions Start ›
- Binary, denary and hexadecimal Start ›
- Binary addition, overflow and negative numbers Start ›
- Prefixes and character sets Start ›
- Working through the long questions Start ›
Syllabus for this subtopic 8 points
- Binary magnitudes; binary prefixes (kibi, mebi, gibi, tebi) and decimal prefixes (kilo, mega, giga, tera)
- Number systems: binary, denary, hexadecimal and Binary Coded Decimal (BCD)
- One's complement and two's complement representation
- Conversion of an integer between number bases and representations
- Binary addition and subtraction using positive and negative integers
- How overflow can occur
- Practical applications of BCD and hexadecimal
- Character sets: ASCII, extended ASCII and Unicode
1.2 Multimedia all covered 9/9 sheet questions Start ›
Syllabus for this subtopic 6 points
- Bitmap images: pixel, file header, image resolution, colour depth
- Estimating the file size of a bitmap image
- Effects of changing the resolution and the colour depth
- Vector graphics: drawing object, property, drawing list
- Justifying the use of a bitmap image or a vector graphic
- Representation of sound: sampling, sampling rate, sampling resolution
1.3 Compression all covered 10/10 sheet questions Start ›
Syllabus for this subtopic 3 points
- The need for compression
- Lossy and lossless compression
- Compressing a text file, a bitmap image and a sound file; run-length encoding
3Hardware weeks 5–6 Start unit ›
3.1 Computers and their components all covered 12/12 sheet questions Start ›
- Components, devices and buffers Start ›
- RAM, ROM and the memory types Start ›
- Embedded systems, sensors and control Start ›
Syllabus for this subtopic 6 points
- The need for input, output, primary and secondary storage
- Embedded systems, and their benefits and drawbacks
- Principal operations of a range of hardware devices
- The use of buffers
- RAM and ROM; SRAM and DRAM; PROM, EPROM and EEPROM
- Sensors, and monitoring and control systems
3.2 Logic Gates and Logic Circuits all covered 12/12 sheet questions Start ›
Syllabus for this subtopic 3 points
- Symbols and functions of the NOT, AND, OR, NAND, NOR and XOR gates
- Truth tables for each gate
- Construction of logic circuits, truth tables and logic expressions
2Communication weeks 13–14 Start unit ›
2.1 Networks including the internet all covered 12/12 sheet questions Start ›
- Networks, LAN and WAN, and who is in charge Start ›
- Topologies, hardware and Ethernet Start ›
- The internet, IP addressing and DNS Start ›
Syllabus for this subtopic 3 points
- Networks, including the internet: LAN, WAN, client–server and peer-to-peer
- Hardware a network needs, and the media that carry it
- The internet, IP addressing and the domain name service