Computer Hardware and Software

Computer Components

• A computer consists of hardware and software.

Hardware

• Physical parts of a computer such as the CPU, memory, bus, and storage devices.
• Tangible and can be physically touched or seen.
• Necessary for a computer to function.
• Classified as internal or external based on placement in relation to the device.
• Internal hardware examples: video cards, memory, and the core processing unit (CPU).
• External hardware examples: keyboard, mouse, and computer case.

Software

• Instructions stored and run on hardware.
• Programs and procedures that perform tasks on a computer.
• Two types: system software and application software.

System Software

• Directly operates computer hardware.
• Provides basic functionality to users and allows other software to operate smoothly.
• Controls a computer's internal functioning and hardware devices like monitors, printers, and storage.
• Acts as an interface between hardware and user applications, translating between human-readable languages and machine language (1s and 0s).
• Three Subtypes: Operating Systems, Language Processors, and Device Drivers

Operating System (OS)

• The main program of a computer system.
• First software to load into memory when the computer is turned on.
• Manages resources like computer memory, CPU, printer, and hard disk.
• OS provides an interface for user interaction and offers services to other software.
• Examples include Linux, Apple macOS, and Microsoft Windows.

Language Processor

• System software component that converts human-readable language into machine language, and vice versa.
• Converts high-level programming languages (e.g., Java, C, C++, Python) into machine-readable instructions (object code or machine code).

Device Driver

• Software that controls a device and enables it to perform its functions.
• Every device requires a driver to connect with the computer system
• When connecting a new device, a driver is needed to inform the operating system how to control it.

Application Software

• Performs special functions beyond basic computer operations.
• Designed for specific tasks for end-users.
• Fulfills end-users' requirements.
• Includes word processors, spreadsheets, database management, inventory, and payroll programs.

General Purpose Software

• Application software used for a variety of tasks.
• Not limited to a specific function (e.g., MS-Word, MS-Excel, PowerPoint).

Customized Software

• Designed software to perform specific tasks/functions for specific organizations.
• Examples include railway reservation, airline reservation, and invoice management systems.

Utility Software

• Designed to support computer infrastructure.
• Analyzes, configures, optimizes, and maintains the system.
• Provides solutions such as antivirus, disk defragmentation, memory testing, disk repair, disk cleanup, registry cleaning, and disk space analysis.

Hardware and Software Interaction

• Software instructs the hardware on tasks to perform.
• Hardware enables the performance of those tasks.

Hardware vs. Software

Hardware and Software Similarities

• Both are necessary parts of a computer.
• Neither is easy to develop.
• Both require ongoing upgrades.
• They are completely reliant on one another.
• Both can be expensive.

Functional Units of a Computer

• Basic components that aid the working-cycle, following the Input-Process-Output Cycle
• Consists of five functionally independent parts: input unit, memory unit, arithmetic logic unit (ALU), output unit, and control unit.

Input Unit

• Accepts digitally coded information using input devices

Memory Unit

• Stores programs and data
• Divided into primary and secondary types

Primary Memory

• Commonly called main memory
• Fast memory used for the storage of programs and active data (data currently in process)
• Consists of semiconductor storage cells, each capable of storing one bit of information
• Main memory consists of only randomly accessed memories
• RAM and cache memory are examples

Secondary Memory

• Used for storing large amounts of data and programs, particularly information that is accessed infrequently
• Examples include magnetic disks and tapes, optical disks (CD-ROMs), and floppies

Arithmetic Logic Unit (ALU)

• Executes most computer instructions (addition, subtraction, division, multiplication, etc.)
• Operands are brought into the ALU from memory and stored in high-speed storage elements called registers
• Instructions are performed in a required sequence.

Control Unit

• Serves as the nerve center of the computer
• Sends signals to other units and monitors their status
• Generates timing signals that govern data transfer between the input unit, processor, memory, and output unit.

Output Unit

• Counterpart to the input unit
• Its function is to send the processed results to the outside world
• Examples include printers, speakers, and monitors

Interconnection Between Functional Components

• Consists of an input unit, CPU, and output unit.
• Components communicate through a common bus.
• Bus: a transmission path made of conducting wires for data/information transfer.
• System bus: connects major components (CPU, memory, I/O modules) as a set of conductors
• Separated into three functional groups: data bus, address bus, and control bus.
• Data bus carries the data or instruction.
• Address bus carries the location of the data or instruction.
• Control bus carries the control signals.

Computer Peripheral Devices

• An auxiliary device (e.g., mouse, keyboard) that connects to and works with the computer.
• Any device that connects to the computing unit but is not part of the core architecture.
• Core: CPU, motherboard, and power supply.
• Can be external (printer connected with a cable) or internal (optical disc drive inside the computer case).
• Internal peripherals referred to as integrated peripherals; external ones are more commonly implied when people refer to "peripherals."
• Examples: expansion cards, graphics cards, image scanners, tape drives, microphones, loudspeakers, webcams, and digital cameras.

Types of Peripheral Devices

• Classified into three types: input device, output device, and input/output device.

Input Device

• Inserts data or commands into the computer system.
• Examples: keyboard, mouse, scanner, barcode reader, digital pen, webcam, and microphone.

Output Device

• Receives processed data from the computer and presents it to the user.
• Examples: monitor, printer, speaker, headphone, and projector.

Input/Output (I/O) Device

• Performs both input and output functions.
• Examples: hard drive, USB drive, memory card, tape drive, and NIC.

Peripheral Device Examples

• Keyboard: Allows the user to enter letters, numbers, and symbols; sends a unique signal to the computer when a key is pressed.
• Mouse: Uses point-and-click technology.
• Webcam: Captures live videos and photos; mainly used for video calls and live presentations.
• Scanner: Used to scan documents to save and store a soft copy.
• Monitor: Receives output from the processing unit and displays it; temporary output is called the soft copy.
• Printers: Print to produce hard copy.
  • Dot-matrix Printer: uses pins and an ink-coated ribbon for printing.
  • Inkjet Printer: uses liquid ink for printing.
  • Laser Printer: uses a laser toner for printing.
• Speaker: Plays audio output signals.
• Hard Disk: Provides both input and output.
• USB Drive: Used to transfer data between computers connected.
• NIC (Network Interface Card): Used to connect to a network.