← Computer Science syllabus

SingaporeComputer Science

Computer Systems and Architecture

4 dot points across 4 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

What is the difference between hardware and software, and between system and application software?

Distinguish hardware from software, and system software (operating system) from application software, with examples
A focused answer to the O-Level Computing point on hardware and software. The difference between physical hardware and programs, the role of the operating system as system software, and how it differs from application software.
6 min answer →

What are input, output and storage devices, and how do they fit the input-process-output model?

Classify peripherals as input, output or storage devices, and explain the input-process-output model of a computer system
A focused answer to the O-Level Computing point on peripherals. Classifying devices as input, output or storage, the input-process-output model with feedback, and choosing suitable devices for a task.
6 min answer →

What is the difference between RAM, ROM and secondary storage, and why does a computer need each?

Distinguish RAM, ROM and secondary storage, explaining volatility and the purpose of each in a computer
A focused answer to the O-Level Computing point on memory and storage. The difference between RAM and ROM, what volatile means, the role of secondary storage, and why a computer needs all three.
6 min answer →

What does the CPU do, and how does the fetch-execute cycle run a program?

Describe the role and main parts of the CPU, the fetch-execute cycle, and how clock speed and cores affect performance
A focused answer to the O-Level Computing point on the CPU. The role of the processor, its main parts, the fetch-execute cycle that runs every instruction, and how clock speed and the number of cores affect performance.
6 min answer →