Computer Repair Book

1.2. Basic Computer Components

1 Central Processing Unit (CPU)

·         Definition: The CPU is the brain of the computer, responsible for executing instructions and performing calculations.

·         Components:

o    Control Unit (CU): Manages and coordinates the activities of the CPU.

o    Arithmetic Logic Unit (ALU): Performs arithmetic and logical operations.

o    Registers: Small, fast storage areas within the CPU used to hold data and instructions temporarily.

·         Types:

o    Single-core CPUs: Process one instruction at a time.

o    Multi-core CPUs: Contain multiple processing units, allowing for parallel processing.

o    Hyper-threading CPUs: Simulate multiple CPUs by allowing each core to handle multiple threads.

·         Performance Metrics:

o    Clock Speed: Measured in GHz, indicating how many cycles the CPU can perform per second.

o    Number of Cores: More cores generally mean better performance for multi-threaded tasks.

o    Cache Size: The amount of fast memory available to the CPU for temporary storage.

2 Memory

·         Random Access Memory (RAM)

o    Definition: Temporary storage used by the CPU to store data and instructions that are currently being processed.

o    Types: DDR3, DDR4, etc.

o    Characteristics: Volatile (data is lost when power is turned off).

·         Read-Only Memory (ROM)

o    Definition: Non-volatile memory used to store firmware and BIOS.

o    Characteristics: Data is not lost when power is turned off.

3 Storage Devices

·         Hard Disk Drives (HDD)

o    Definition: Mechanical storage devices that use spinning disks and read/write heads to store data.

o    Characteristics: High capacity, slower access times compared to SSDs.

·         Solid State Drives (SSD)

o    Definition: Non-mechanical storage devices that use flash memory to store data.

o    Characteristics: Faster access times, no moving parts, more durable.

·         External Storage

o    USB Drives: Portable storage devices that connect via USB.

o    External HDDs/SSDs: Larger capacity storage devices that connect via USB or other interfaces.

4 Input Devices

·         Keyboard

o    Types: Mechanical, membrane, wireless.

o    Functions: Allows users to input text and commands.

·         Mouse

o    Types: Optical, laser, wireless.

o    Functions: Allows users to navigate and interact with the graphical user interface.

·         Other Input Devices: Microphones, webcams, scanners, joysticks.

5 Output Devices

·         Monitor

o    Types: LCD, LED, OLED.

o    Functions: Displays visual output.

·         Printer

o    Types: Inkjet, laser, 3D.

o    Functions: Produces hard copies of documents and images.

·         Speakers

o    Functions: Produces audio output.

6 Motherboard

·         Definition: The main circuit board of a computer that connects all the components.

·         Components:

o    CPU Socket: Where the CPU is installed.

o    Memory Slots: Slots for RAM modules.

o    Expansion Slots: Slots for additional cards (e.g., graphics card, sound card).

o    Ports: USB, HDMI, Ethernet, etc.