Computer Fundamentals
What is asked
Generations of computers, hardware and peripherals, memory hierarchy and units, number systems, logic gates, software categories and basic terminology.
Core facts
- Generations: first - vacuum tubes; second - transistors; third - integrated circuits; fourth - microprocessors; fifth - artificial intelligence and ULSI.
- Memory: 1 byte = 8 bits; 1 KB = 1024 bytes, and MB, GB and TB follow the same 1024 step.
- RAM is volatile; ROM is non-volatile. Cache is fastest, then RAM, then secondary storage.
- Input devices: keyboard, mouse, scanner, OMR, MICR, barcode reader. Output: monitor, printer, plotter.
- Number systems: binary base 2, octal base 8, decimal base 10, hexadecimal base 16.
Worked example
“Convert binary 1011 to decimal.” Expand by place value: 1×2³ + 0×2² + 1×2¹ + 1×2⁰ = 8 + 0 + 2 + 1 = 11. Shortcut check: 1011 groups to B in hexadecimal, and B equals 11, which confirms the answer.
Traps that cost marks
- Saying 1 KB = 1000 bytes; the exam convention is 1024.
- Calling ROM volatile, or calling cache secondary storage.
- Confusing input with output when a device does both, as a touchscreen does.
- Mixing hardware with firmware and software in classification questions.
- Forgetting that the first generation used machine language, not high-level languages.