Information Technology Theory Notes

Hardware vs. Software

  • Hardware: Physical components (CPU, RAM, etc.).

  • Software: Programs that run on hardware (OS, applications).

ICT Systems

  • Integrate hardware, software, data, and networks.

  • Examples: Banking systems, e-commerce.

IPO Model

  • Input: Data/instructions received.

  • Processing: CPU processes data.

  • Output: Result delivered (display, print, save).

Advantages of Computers

  • Speed and Efficiency: Fast data processing.

  • Accuracy: Precise calculations.

  • Automation: Automates repetitive tasks.

  • Data Storage and Retrieval: Vast storage and quick retrieval.

Disadvantages of Computers

  • Dependence: Over-reliance on computers.

  • Cybersecurity Threats: Vulnerable to attacks.

  • Job Displacement: Automation leads to job losses.

  • Cost: Expensive to acquire and maintain.

Data vs. Information

  • Data: Raw, unprocessed facts.

  • Information: Processed, structured, contextualized data.

Types of Computer Systems

  • Laptops: Portable, built-in peripherals.

  • Desktop: Stationary, powerful, upgradeable.

  • Server: Provides services over a network.

  • Embedded Computers: Dedicated systems in larger devices.

  • Smart Wear: Wearable devices with computing features.

  • Tablets: Portable, touchscreen-based.

  • Smartphones: Compact, connected devices.

  • Single Board Computers: (Raspberry Pi, Arduino); compact computers for education and control.

Classification by Portability/Mobility

  • Laptops, Tablets, Smartphones: Lightweight, battery-powered, wireless.

Classification by Processing Power

  • Supercomputer: Most powerful, used for complex tasks.

  • Server: High processing power for network management.

  • Desktop: Moderate processing power for general use.

  • Laptop: Moderate processing power, throttled for battery life.

  • Mobile: Lower processing power for lightweight tasks.

Computer Components

  • CPU, RAM, HDD/SSD/NVMe, Motherboard, PSU, GPU, Case/Fans

  • Primary vs Secondary Storage

CPU Design

  • Parallel Processing: Simultaneous task handling.

    • Hyper-Threading: Single core handles multiple threads.

    • Multi-Processing: Multiple physical cores.

  • Registers: Fast memory within CPU.

    • Number of Bits: Affects processing speed and complexity.

  • ALU: Arithmetic and logical operations.

  • CU: Directs data flow and interprets instructions.

CPU and RAM Performance

  • CPU Speed: Measured in GHz.

  • RAM Speed: Measured in MHz or DDR.

  • Latency: Delay in data transfer.

SRAM and Cache

  • SRAM: Fast memory used in CPU caches.

  • Cache: High-speed memory storing frequently accessed data.

    • L1 Cache: Fastest, smallest, within CPU core.

    • L2 Cache: Slower than L1, larger, near CPU core.

    • L3 Cache: Slowest, largest, shared across cores.

Types of Caching

  • Processor Cache: Data and instructions for CPU.

  • Disk Cache: Data from hard drive.

  • Browser Cache: Website data.

  • Proxy/Web Cache: Web resources in proxy server.

Motherboard

  • Connects CPU, memory, storage, and peripherals.

  • System Clock: Synchronizes component operations.

    • Overclocking: increasing clock speed beyond limits, increasing risks

    • Clock Multiplication: increase clock speed within inherent design

    • Turbo Boost: Increase preformance within limits when needed

  • Internal Bus/FSB:

    • Data Bus: Transfers data.

    • Address Bus: Carries memory addresses.

    • Control Bus: Sends control signals.

External Buses

  • Speed vs. Throughput: How fast data travels vs amount transferred.

  • PCIe: High-speed for graphics cards and SSDs.

  • SATA: For storage devices, slower than PCIe.

  • USB: Versatile, various speeds.

Parallel Processing Techniques

  • Multi-tasking: OS runs multiple tasks concurrently.

  • Multi-threading: Program divided into concurrent threads.

  • Hyper-threading: Single CPU core handles two threads.

  • Multi-processing: Multiple CPU cores.

Machine Cycle

  • Fetch, Decode, Execute, Store

Interrupts

  • Signals that inform the CPU of immediate needs.

  • IRQs: Hardware lines signaling CPU.

  • I/O Range: Addresses for hardware devices.

Virtual Memory

  • Using hard drive as RAM when physical RAM is full.

  • Swapping: Moving data between RAM and virtual memory.

  • Slows down processing speed.

Modular Design

  • Components easily replaced or upgraded.

    • Ports: External connectors (USB, HDMI, SATA).

    • Cards vs. Onboard Components: Dedicated cards offer better performance.

    • Buses: Transfer data; faster buses improve throughput.

Co-Processors

  • Specialized processors for specific tasks.

    • GPU: accelerated graphic, video, and gaming tasks.

    • Maths Co-Processor: performs complex mathematical calculations.

Techniques to Improve Processor Speed

  • Hyper-Threading and Multi-Processing.

  • Increasing Cache.

  • Register Size Effects.
    *Clock Multiplication and Overclocking

Increasing RAM Speed and Size

Improving Components for Specific Tasks

  • Video Card for 3D Rendering.

  • Faster HDD/SSD for Video Editing.

Primary Storage

  • Registers: Fastest, smallest, volatile.

  • CPU Cache: Fast, small, volatile.

  • RAM: Slower than cache, larger, volatile.

Secondary Storage

  • Flash Memory: Faster than HDDs, limited write cycles.

  • HDD: Slower, high capacity, prone to mechanical failure.

  • SSD: Faster than HDDs, more reliable, expensive.

  • External Hard Drives: Portable, depends on drive type.

  • Cloud Storage: Dependent on internet speed, scalable, reliable with redundancy.

System Software

  • Manages computer hardware and resources.

BIOS and UEFI

  • BIOS: Firmware to initialize hardware.

  • UEFI: Modern BIOS replacement with advanced features.

Operating Systems (OS)

  • Manages hardware and software resources.

  • Desktop OS: Windows, macOS, Linux.

  • Mobile OS: Android, iOS, iPadOS.

  • Embedded OS: Embedded Linux, RTOS

OS Functions

  • Provide User Interface (GUI, CLI).

  • Load and Run Programs.

  • Manage Resources (CPU, Memory, Storage).

  • Interface between Hardware and Applications.

Programming Tools

  • Compilers, Debuggers, IDEs, Text Editors

Source Code vs Executable Code/Bytecode

  • Source Code: Human-readable code.

  • Executable Code/Bytecode: Machine-readable code.

Utilities

  • Maintain, manage, and protect the computer.

Drivers

  • Enable communication between OS and hardware.

Application Software

  • Helps users perform specific tasks.

    • Stand-alone Applications.

    • Network Applications.

Data Transfer and Synchronizing

  • Moving data between devices/systems and keeping data identical/up-to-date.

Distribution and Licensing Models

  • Open Source: Freely available source code.

  • Proprietary: Owned, requires license.

  • Freeware: Free to use, proprietary.

  • Freemium: Free basic features, paid advanced features.

  • Creative Commons: Specifies usage permissions for digital content.

Types of Programming Tools

  • Language Translators.

  • High-Level Languages: Closer to human language.

  • Low-Level Languages: Closer to machine language.

Compilers

  • Translates the entire high-level source code into machine code (one/two-stage).

Interpreters

  • Translates and executes code line-by-line.

Assemblers

  • Translates assembly language into machine code.

Operating System Tools and Utilities

  • Manage and optimize data, devices, and security for devices.

Structuring Data

  • Management of Desktop.

  • Management of Files and Folders.

  • Archive.

  • Backup.
    *Compress/Decompress Files.

System Management

  • Installing/Uninstalling Software.

    • Custom Installation.

    • Full Installation.

  • Adding Devices and Device Drivers.

  • Scheduling/Updating.

Security Features

  • Firewall: Monitors network traffic.

  • Anti-malware: Detects and removes malicious software.

Computer technologies implications

  • Societal Impacts

    • Gender:
      *Positive: empower, remove opportunities
      *Challenges: Gender gap reinforcing stereotypes
      *Race and Ethnicity:
      *Positive: Inclusion and representation, cultural preservation
      *Challenges: AI and algorithmic bias
      *Cultural and Religion:
      *Positive: Cross-cultural communication
      *Challenges: Cultural erosion
      *Environmental:
      *Positive: Sustainable technologies
      *Challenges: E-waste, energy Consumption
      *Economic :
      *Positive: Job Creation, global marketplace
      *Challenges: Job displacement, Digital Divide