ICSE · Grade 3
Ch. 1: Computer System
What is a computer system? Hardware vs software, IPO cycle, CPU (MU, CU, ALU), input and output devices — with a fun interactive lab.
Define computer system
Hardware vs software
CPU parts
Input and output devices
IPO cycle
💻 Grade 3 · Computer
Computer System Lab
Hardware you can touch · Software you cannot · Watch the IPO cycle work!
Computers everywhere
🚀
Space research
🏢
Offices
🏥
Hospitals
🛡️
Defence
✈️
Airport
🎬
Animation
🏦
Banks
🎨
Designing
A computer is a useful machine — play games, write, draw, listen to music, store information and solve sums… very fast!
Hardware
Physical parts you can touch: keyboard, mouse, monitor, CPU cabinet, motherboard, hard drive, RAM…
Software
Programs and instructions you cannot touch. They tell hardware what to do. Without software, hardware is useless!
IPO cycle — how a computer works
Input
Data in
→
Process
CPU works
→
Output
Result out
Example: type 2 + 2 → CPU calculates → monitor shows 4
CPU — brain of the computer
MUMemory Unit — stores data & instructions
CUControl Unit — traffic policeman of the computer
ALUArithmetic Logic Unit — does maths & decisions
Monitor = Visual Display Unit (VDU). Soft copy = what you see on screen.
Input devices
- Keyboard
- Mouse
- Scanner
- Microphone
- Webcam
Output devices
- Monitor
- Printer
- Speaker
- Headphones
- Projector
# Summary
1. Computer = useful fast machine.
2. Hardware = touchable parts.
3. Software = programs.
4. IPO = Input Process Output.
5. CPU = MU + CU + ALU.
6. Input: keyboard/mouse. Output: monitor/printer.
Topics in this chapter
-
What is a computer?
Useful machine used almost everywhere — games, writing, music, sums.…
-
Hardware
Physical parts you can touch — keyboard, mouse, monitor, CPU cabinet.…
-
Software
Programs and instructions — cannot touch; needed for hardware to work.…
-
CPU
Brain of computer: Memory Unit, Control Unit, ALU.…
-
IPO cycle
Input → Process → Output.…
Philosophy check
- What is this civilization?
- Why was it advanced?
- How did cities work?
- Where do we still see these ideas?
- Exams — what will be asked?