Computer components, storage and embedded systems

Learning objectives

Identify the main hardware components of a computer system — processor, main memory, secondary storage, input devices, output devices and the buses that link them — and state the function of each

Compare RAM with ROM on volatility, whether they can be written to and what they typically hold, and distinguish DRAM from SRAM and PROM from EPROM and EEPROM

Describe how a magnetic hard disk, a solid-state drive and an optical disc each store data, and compare them on capacity, access speed, durability and cost per gigabyte

(A Level) Explain the purpose of virtual memory, describe how pages move between main memory and backing store, and explain what causes disk thrashing and how it shows itself to the user

Describe an embedded system as a computer built into a larger device to carry out one dedicated task, give examples such as domestic appliances and vehicle control units, and state its advantages and limitations

Select suitable input and output devices for a stated application and justify each choice against the requirements of the task

Outline how a laser printer, a 3D printer, a microphone, a speaker, a touchscreen and a virtual reality headset each work

Explain why a buffer is needed when data passes between devices that work at different speeds, such as a processor and a printer

Distinguish a monitoring system from a control system, and explain the parts played by sensors, actuators and feedback