Explain the basic operations of a computer with the help of a diagram.
How to lay out the answer. Follow the frame, then write it in your own words.
1 · Open in two lines. A computer is an electronic device that accepts data, processes it under a stored program, gives out information and stores it for later use.
2 · Draw the cycle. [Diagram: Input → Processing (CPU) → Output, with Storage linked to all three]
3 · Input. Data enters through input devices such as the keyboard, mouse, scanner and barcode reader, and is changed into a form the computer can read.
4 · Processing.
The CPU does the work: the control unit directs, the ALU calculates and compares, registers hold the item in use.
It repeats the machine cycle: fetch, decode, execute, store.
5 · Output. Results are given as soft copy (screen, sound) or hard copy (printouts).
6 · Storage.
Primary memory: RAM (temporary) and ROM (permanent).
Secondary storage: hard disk, SSD, pen drive, keeps data after power is off.
7 · Sri Lankan business example. A supermarket till: scanner (input), CPU adds the bill (process), receipt (output), sale saved for stock reports (storage).
8 · Close in one line. These four operations turn raw data into information for decisions, but only if the input is correct (GIGO).
Scoring tip: The diagram and the CPU parts carry most marks. Give one example for each operation.
