Chapter 1: Types and Components of Computer Systems Study Notes
Hardware and Software
Definition of Hardware: Hardware refers to all the physical parts of a computer system that an individual can see, touch, and pick up.
External Hardware Examples: Keyboard, Speaker, Printer, Microphone, and Monitor.
Internal Hardware Examples: Hard disk, RAM (Random Access Memory), CPU (Central Processing Unit), Graphics card, Sound card, Network Interface Card (NIC), and Motherboard.
Definition of Software: Software consists of coded programs that control how the computer works; these are components that you cannot see, touch, or pick up.
Types of Software:
System Software: This software provides the essential services that the computer requires to operate efficiently. It includes operating systems and various utilities to ensure the system runs smoothly.
Operating System (OS): Manages computer hardware and software resources and provides common services for computer programs.
Compilers: Programs that translate high-level language (HLL) code (e.g., Java, Visual Basic, C++) into machine code understood by the computer.
Linkers (Link Editor): A program that takes one or more object files produced by a compiler and combines them into a single executable program.
Device Drivers: Software that enables hardware devices (e.g., printers, memory sticks, mice, CD drives) to communicate with the operating system.
Utilities: Programs that help manage, maintain, and control program resources. Notable utility tasks include:
Deleting data
Disk defragmentation
Management of user accounts and security
Anti-virus software
Software updates
System cleanup
Encryption/decryption
Formatting
Application Software: Programs that allow the user to perform specific tasks to solve a problem or fulfill a requirement.
Examples: Word processor, Spreadsheet, Databases, Control and measuring software, Applets and Apps, Photo editing software, Video editing software, and Graphics manipulation software.
Main Components of Computer Systems
General Hardware Divisions:
Input Devices
Central Processing Unit (CPU)
Output Devices
Backing Storage Devices
The Central Processing Unit (CPU) or Microprocessor:
Described as the 'brain' of the computer.
It is the device that carries out software instructions.
Physically located on the motherboard.
Responsible for searching and sorting data, performing calculations, and decision-making.
Components of the CPU:
Control Unit (CU): Manages the flow of data and control signals.
Arithmetic and Logic Unit (ALU): Performs mathematical calculations and logical comparisons.
Main Memory (RAM).
Internal Memory:
Random Access Memory (RAM):
An internal chip where data is temporarily stored while applications are running.
It is volatile memory; contents are lost if the power is turned off.
It can be both read from and written to.
When in use, RAM contains the Operating System software, the application software currently running, and any data being processed.
Read Only Memory (ROM):
Pre-written memory that holds the instructions for booting up the computer.
Contains the BIOS (Basic Input Output System), which checks hardware and loads the OS into RAM.
The BIOS stores system configuration, date, and time in a CMOS (Complementary Metal Oxide Semiconductor) chip.
It is non-volatile (permanent) storage; data is not lost when power is removed.
Storage and Data:
Internal Hard Disk Drive (HDD) / Solid State Drive (SSD): The primary internal storage for system software, application software, and user files (e.g., photos, text, music).
Backing Storage (Secondary Storage): Non-volatile devices used for long-term data storage that retain information even when the computer is powered off.
Analogue Data: Real-world data (sound, temperature, light) that is continuous and changes smoothly. It must be converted using an Analogue to Digital Converter (ADC) for computer processing.
Digital Data: Data in a discrete format that computers understand (binary 0s and 1s). Digital signals are converted to analogue using a Digital to Analogue Converter (DAC) to interact with the real world (e.g., through speakers or motors).
Operating Systems and User Interfaces
User Interface Definition: The system used by people to interact with a computer, allowing them to issue commands and view results.
Types of Interfaces:
Graphical User Interface (GUI): Allows interaction via pictures or icons. Often called a WIMP interface: Windows, Icons, Menus, Pointer.
Command-Line Interface (CLI): A black screen where users must type specific commands. Requires learning a complex set of commands and provides no visual clues; primarily suitable for expert users.
Dialogue-based Interface: Uses the human voice to provide commands. Examples include luxury car systems (e.g., "Hey BMW, drive me to the nearest airport") for hands-free control of navigation or entertainment.
Gesture-based Interface: Relies on human movement (hands, head, or feet). Uses computer vision and image processing to enable natural interaction without mechanical devices.
Types of Computers
Desktop PC:
Features: Found in homes, used by one person at a time for gaming, homework, or internet access.
Advantages: Better performance for the price, cheaper than laptops, easier to use large keyboards, and metal cases provide better cooling. Generally more powerful.
Disadvantages: Not portable; requires a constant power supply.
Laptop:
Features: Portable, battery-powered, built-in screen, keyboard, and touchpad. Almost as powerful as a desktop.
Advantages: Highly portable, integrated Wi-Fi, low power consumption components.
Disadvantages: Risk of losing work if the battery dies, smaller keyboards can be difficult, prone to theft in public, and compact design can lead to overheating.
Tablets:
Features: High-definition anti-glare displays, front/back cameras, Bluetooth, flash memory, cloud storage, and sensors (proximity, accelerometer, voice recognition).
Advantages: Very fast boot times, fully portable, simple interface, long battery life, and useful standby modes for alerts.
Disadvantages: Limited storage, typing is slow/error-prone, difficult file transfers, and limited software compatibility.
Smartphones:
Features: Email, web browsing, GPS, calendar, banking, VoIP, video/music streaming, social networking, and instant messaging.
Advantages: Small, lightweight, always connected (3G, 4G, Wi-Fi), and offers hundreds of apps.
Disadvantages: Hard to read/type, high battery drain during browsing, small memory, easy to lose/steal, and not all websites are compatible.
Phablets:
Advantages: Larger screens than regular phones for videos/reading; good for multitasking. Can replace carrying both a phone and a tablet.
Disadvantages: Bulky for pockets, expensive, and difficult for one-handed use.
Impact of Emerging Technologies
Artificial Intelligence (AI): The capability of a machine to imitate intelligent human behavior, learning from data and adapting to new inputs. Examples include smart assistants, recommendation engines, and autonomous vehicles.
Extended Reality (XR): An umbrella term for immersive technologies that combine real and virtual environments.
Virtual Reality (VR): A fully simulated 3D environment, typically experienced through a headset (e.g., Oculus Rift, HTC Vive). Used for gaming, education (virtual field trips), and professional training (medicine, aviation).
Augmented Reality (AR): Overlays digital information (images/sounds) onto the real world. Examples include Pokémon GO, Snapchat filters, IKEA's furniture visualization app, and AR maps.
Mixed Reality (MR): Blends the real and virtual worlds, allowing real and digital objects to interact in real time. Examples include rotating virtual 3D organs in a classroom or designing a virtual volcano on a physical table.