Computer Hardware: CPU functions

• Computers are made of hardware (physical components) and software (programs).
• Knowing hardware and software is key to using, fixing, and keeping computers running well.

Central Processing Unit (CPU)

• The CPU is the computer's brain and handles most of the work.
• It does all types of data processing, from basic math to complex tasks.
• The CPU can be put into a CPU socket, usually found on the motherboard.
• The CPU has 3 main parts: Memory or Storage Unit, Control Unit, and ALU (Arithmetic Logic Unit).

CPU Functions

Memory or Storage Unit

• Stores data and instructions needed for processing.
• Stores temporary results from calculations or tasks.
• Keeps processed results before sending them to an output device.
• Sends all inputs and outputs through the memory unit.

Control Unit

• Manages data, transfers, and instructions among computer parts.
• Manages all units of the computer.
• Gets instructions from memory, understands them, and tells the computer what to do.
• Handles communication with input and output devices for data transfer.

ALU (Arithmetic Logic Unit)

• Arithmetic Logic Unit is for math and logic operations, with two sections:
• Arithmetic Section: It does basic math (add, subtract, multiply, divide) and uses these for more complex operations.
• Logic Section: It handles logical tasks like selecting, comparing, matching, and combining data.

CPU Operations

• The main job of a computer processor is to run instructions and give an output, which involves fetching, decoding, and executing.
• Fetch: The CPU gets the instruction, which is in binary numbers passed from RAM.
• Decode: The CPU figures out the instruction, using the ALU, to start the decoding process.
• Execute: The instructions are ready to be carried out after decoding.
• Store: The instructions are stored in memory after being executed.

Types of CPUs

• Single Core CPU: The oldest type, used in the 1970s, with one core for all operations, processing one operation at a time, and not good for multitasking.
• Dual-Core CPU: Has one integrated circuit with two cores, each with its own cache and controller that work together, making them faster than single-core CPUs.
• Quad-Core CPU: Contains two dual-core processors in one chip, with four separate cores, which speeds up programs.

Motherboard

• A motherboard is a circuit board that holds electrical components and helps them communicate.

Key Motherboard Components

• Mouse and keyboard connectors
• Universal serial bus (USB)
• CPU
• RAM memory
• Basic input/output (BIOS) system
• Chipsets
• Cooling fans
• Adapter cards and expansion slots
• CMOS battery
• Front panel connectors
• Storage devices
• Power connector

Motherboard Functions

• Manages data flow
• Conserves resources
• Optimizes power distribution
• Drives communication
• Enhances performance
• Improves reliability
• Enables productivity

Memory

• Memory can be divided into primary (main) and secondary (auxiliary) types.
• Primary memory is split into volatile (RAM) and non-volatile (ROM, flash memory) types.

Primary Memory Types

RAM (Random Access Memory)

• RAM is the main memory the CPU uses for running processes and data.
• Types of RAM:
• DRAM (Dynamic RAM): Common in most computers and electronics.
• SRAM (Static RAM): Keeps data as long as power is on.

ROM (Read-Only Memory)

• ROM has key instructions and data that cannot be easily changed.
• Types of ROM:
• PROM (Programmable Read-Only Memory): It can be programmed once by the user using a special device.
• EPROM (Erasable Programmable Read-Only Memory): It can be erased by exposure to ultraviolet light and reprogrammed.

Secondary (Auxiliary) Memory

• Flash Memory: A non-volatile memory that can be erased and reprogrammed electronically.
• Hard Drives (HDDs): Traditional magnetic storage devices that store large amounts of data.
• Solid State Drives (SSDs): Modern storage devices that use flash memory for data storage.
• Other Secondary Storage: Includes USB drives, CDs, and DVDs.

Other Memory Types

• Cache Memory: Fast memory for quick access to frequently used data by the CPU.
• Virtual Memory: Uses hard disk space as extra RAM, allowing the computer to handle more data.

Input/Output Devices

• Input devices send data to a computer, while output devices show or reproduce data.

Input Devices

• Keyboard: For typing characters and functions.
• Mouse: Sends information to the computer.
• Microphone: Records sound digitally.
• Light pen: Inputs information by touching the device.
• Joystick: Used for directional control, especially in gaming.

Output Devices

• Printer: Creates a physical copy of an image or document.
• Monitor: Shows information being processed by the computer.
• Speakers: Play audio output.
• Headphones: Allow private audio output.
• Projector: Displays visual information on a screen.

System Software

• Manages computer hardware and software resources to ensure they work well together.
• Examples include operating systems (Windows, macOS, Linux), device drivers, and utility programs.
• Provides a base for application software, manages input/output and memory, and ensures communication between hardware and software.
• System software runs in the background with limited user interaction, typically through the operating system's user interface.

Features of System Software

• Written in a low-level language.
• Smaller in size.
• Complex to understand.
• Located near hardware components.

Application Software

• Designed to help users with specific tasks or problems.
• Examples include word processors (Microsoft Word), web browsers (Chrome, Firefox), image editors (Photoshop), video games, and email clients.
• Uses system software resources to create documents, browse the internet, and edit images.
• Designed for direct user interaction, allowing users to input data, manipulate information, and view results.

Features of Application Software

• Written in a high-level language.
• Requires more storage space compared to system software.
• Performs only a single task
• Easier to build than system software.

Comparison of System Software and Application Software

• System Software:

  • Manages system resources and provides a path for application software to run.
  • Written in low-level languages.
  • General-purpose.
  • Runs when the system starts and stops when the system is turned off.
  • Controls and manages hardware components and application software.
  • Operates in the background until the computer is shut down.
  • No direct interaction with users.

• Application Software:

  • Built for specific tasks.
  • Written in high-level languages.
  • Specific-purpose.
  • Runs as per the user's request.
  • A set of programs for a specific task.
  • Runs in the front end according to the user's request.
  • Connects the user and the computer.

Installing and Uninstalling Software

• To install software: Download the installer from a trusted source, then double-click the file and follow the on-screen prompts.
• To uninstall software: Use the built-in uninstaller in Windows (Start > Settings > Apps > Apps & features) or the Control Panel's Add or Remove Programs.