Computer Fundamentals
Computer Fundamentals
This domain tests how a computer represents, stores and moves data: hardware blocks, memory units, software types and number-system conversion. CCC+ questions often ask you to classify a component or convert a value, so learn definitions precisely.
Core rules
- A von Neumann machine stores program and data in the same memory. The CPU has the ALU for arithmetic/logic, the control unit for sequencing, and registers for temporary data; cache sits between CPU and RAM.
- Memory is volatile (RAM) or non-volatile (ROM, flash, disk). Secondary storage keeps data without power; RAM loses it.
- Binary units: 1 byte = 8 bits, 1 KB = 1024 bytes, 1 MB = 1024 KB. A nibble is 4 bits. Storage marketing may use decimal units, but exam arithmetic normally uses 1024.
- System software includes operating systems, device drivers and utilities; application software performs user tasks. Firmware is stored in ROM/flash and starts hardware.
Worked example
Convert binary 1101 to decimal and hexadecimal. Place values from left: 8,4,2,1. 1101 = 8 + 4 + 0 + 1 = 13. Group the same bits as 1101 = D in hex, because D equals 13. Reasoning: binary to decimal uses powers of 2; decimal to hex uses groups of 4 bits from the right.
Traps
Do not confuse bit and byte: a 64-bit address is not 64 bytes. RAM is fast and volatile; ROM is non-volatile but not the same as disk. A spreadsheet is application software, not system software. When converting, pad binary groups with leading zeros for hex, not trailing zeros.