Computer Fundamentals
What this domain tests
Definitions, the block diagram of a computer, the stored-program idea, hardware categories, memory hierarchy, number systems and software types - the vocabulary every later unit assumes.
Core concepts
- Block diagram: input unit → CPU (ALU + control unit + registers) → output unit, with memory holding both data and instructions.
- Memory: registers are fastest and smallest; cache, RAM, then secondary storage (HDD/SSD, pen drive) get larger and slower. RAM is volatile, ROM is non-volatile.
- Binary is base 2; 1 byte = 8 bits; 1 KB = 1024 bytes (do not write 1000 in this syllabus).
- Software: system software (operating system, utilities, device drivers) vs application software (word processor, spreadsheet, browser).
- Generations: valves → transistors → integrated circuits → microprocessors; each change reduced size, cost and heat.
Worked example
Convert binary 1101 to decimal. Reasoning: write place values 8, 4, 2, 1, multiply each by the bit and add: 1×8 + 1×4 + 0×2 + 1×1 = 13. To go the other way, divide by 2 repeatedly and read the remainders bottom-up, so 13 gives 1101.
Traps that cost marks
- Saying RAM stores data permanently, or that ROM is erased on shutdown.
- Confusing bit (single binary digit) with byte (8 bits) in storage-capacity questions.
- Calling Windows or Linux application software - they are system software.
- Writing 1 KB = 1000 bytes; the exam expects 1024.
- Describing the ALU as doing comparison only - it does arithmetic and logical operations.