Computer Fundamentals
The Computer Fundamentals domain tests the building blocks of a computer: CPU, memory, storage, motherboard, ports and number systems. Questions often ask you to distinguish volatile from non-volatile memory or convert between binary, decimal and hexadecimal.
Core rules and concepts
- Von Neumann architecture: CPU (ALU, control unit, registers), memory and I/O share a bus; the fetch–decode–execute cycle repeats.
- RAM is volatile working memory; ROM is non-volatile firmware storage. Cache (L1/L2/L3) is fast SRAM close to the CPU; SSD storage is non-volatile flash and much faster than a mechanical HDD.
- A bit is one binary digit; 8 bits = 1 byte. Decimal uses base 10, binary base 2, hexadecimal base 16. 1 KB is often 1024 bytes in memory contexts, while storage makers may use 1000.
- Ports and interfaces: USB, HDMI, DisplayPort, Ethernet RJ-45, audio jacks. Match connector and version.
- Motherboard chipsets determine CPU support, RAM type, expansion slots and onboard I/O.
Worked example
Convert binary 1011 0110 to decimal and hex. Split into nibbles: 1011 = 8 + 0 + 2 + 1 = 11 (B); 0110 = 0 + 4 + 2 + 0 = 6. Hex = B6. Decimal = 11 × 16 + 6 = 176 + 6 = 182. Check: 128 + 32 + 16 + 4 + 2 = 182.
Traps that cost marks
Confusing bits and bytes; treating RAM as permanent storage; assuming a higher GHz CPU is always faster; mixing decimal and binary units; ignoring socket/chipset compatibility; calling ROM volatile.