Computer Architecture
How Computers Work
Lesson 1: Introduction to Computer Science
Understanding the building blocks of computing
What We'll Learn Today
- 🖥️ What's inside a computer?
- 🧠 How does a computer "think"?
- 💾 Where does information live?
- 🔢 How computers understand numbers
- ⚡ Why this matters for programming
What is a Computer?
A computer is a machine that:
- Takes INPUT (keyboard, mouse, microphone)
- PROCESSES information (calculations, decisions)
- STORES data (memory, hard drive)
- Gives OUTPUT (screen, speakers, printer)
Think of it as a very fast calculator that can remember things!
Computer Architecture Overview
This is how all the components work together to process information!
The CPU - The Brain
- Executes instructions one at a time, very fast
- Performs calculations (add, subtract, compare)
- Makes decisions (if this, then that)
- Coordinates all other components
Modern CPUs can execute billions of instructions per second!
Your phone's CPU is more powerful than room-sized computers from the 1960s
RAM - Short-term Memory
- Stores data the CPU is currently working with
- Very fast to read and write
- Temporary - loses data when power is off
- Limited space - usually 8-32 GB
Think of RAM like your desk when doing homework - you keep papers you're actively using close at hand
Storage - Long-term Memory
- Stores data permanently (files, programs, photos)
- Slower than RAM but much larger capacity
- Keeps data even when computer is off
- Types: Hard drives (HDD) and Solid State Drives (SSD)
Like a filing cabinet - lots of space for long-term storage, but takes time to find what you need
Data Units: From Tiny to Huge
Understanding how computers measure and organize information:
📱 Bit
Smallest unit: 1 or 0
Like a single light switch
📦 Byte
8 bits together
Can store 1 character (A-Z, 0-9)
🏠 Word
CPU's natural data size
32-bit or 64-bit chunks
🏢 Double Word
2 words together
For bigger numbers/addresses
🎯 Memory Address Game
Click to see how your computer finds data:
Memory Address 1000: 01001000 (Letter 'H')
Memory Address 1001: 01100101 (Letter 'e')
Memory Address 1002: 01101100 (Letter 'l')
Memory Address 1003: 01101100 (Letter 'l')
Memory Address 1004: 01101111 (Letter 'o')
Each byte has its own address, like houses on a street!
How Computers Think: Binary
Computers only understand two states:
ON (1) or OFF (0)
Like a light switch: 💡 or ⚫
Everything is made from combinations of 1s and 0s:
Letter 'A' = 01000001
Number 5 = 00000101
Your favorite emoji = lots of 1s and 0s!
🎯 Let's Explore Your Computer!
Open your computer's system information:
- Windows: Right-click "This PC" → Properties
- Mac: Apple menu → About This Mac
Find and write down:
- CPU/Processor name and speed
- Amount of RAM/Memory
- Storage space available
🔢 Binary Counting Challenge
Let's count to 10 in binary!
Decimal → Binary
0 → 0000
1 → 0001
2 → 0010
3 → 0011
4 → 0100
Can you figure out 5-10?
Why Learn Computer Architecture?
- Better programmer: Understand how your code actually runs
- Debug problems: Know where issues might come from
- Write efficient code: Understand what's fast vs. slow
- Choose right tools: Match solution to the hardware
When you write JavaScript, it eventually becomes instructions for the CPU!
Coming Up Next...
From Hardware to Software
- What is programming?
- How websites work
- Your first HTML page
- Making things appear in a web browser
Ready to start creating? 🚀