Computer Fundamentals and Hardware Organization
What the exam tests
Computer Fundamentals and Hardware Organization tests the stored-program model, CPU organisation, memory hierarchy, motherboard and buses, and common peripherals. Vocational items often ask you to identify a component, select a device for a task, or calculate memory capacity.
Core rules
- A von Neumann machine keeps instructions and data in the same memory; the CPU fetches, decodes and executes.
- CPU = ALU (arithmetic/logic), control unit (timing/control) and registers (fastest storage). The program counter holds the address of the next instruction.
- Buses: address bus carries a location, data bus carries contents, control bus carries read/write and timing signals.
- Memory hierarchy: registers, cache, RAM, secondary storage. RAM is volatile; ROM/firmware is non-volatile. HDD/SSD are secondary storage.
- 1 byte = 8 bits; 1 KiB = 1024 bytes; 1 MiB = 1024 KiB.
- The motherboard connects CPU socket, RAM slots, chipset, storage ports, expansion slots and I/O ports such as USB, HDMI and Ethernet.
- An SMPS converts AC mains to regulated DC; a UPS provides backup power.
Worked example
A CPU has a 20-bit address bus and each addressable unit is 1 byte. Number of locations = 2^20 = 1,048,576. In KiB: 1,048,576 ÷ 1024 = 1024 KiB = 1 MiB. If each location were 2 bytes, capacity would be 2 MiB. The data bus width affects how many bits move per transfer, not the number of addresses.
Traps
Do not confuse KB (1024 bytes) with kb (kilobits). Cache is faster and smaller than RAM, not a replacement. Address bus width sets addressable locations. RAM loses contents on power-off; ROM does not. HDMI carries digital audio/video, not storage.