Computer Hardware & Software

• The computer includes hardware, software, programs, data, and connectivity
• Components of a computer system are the fundamental elements that make electronic equipment function smoothly
• Students will be able to explain the different physical components of computer systems used in computer networks

Basic Functions of a Computer

• Input
• Process
• Output
• Storage

Hardware

• Refers to the physical components of a computer
• Any part of the computer that can be touched
• Primary electronic devices used to build the computer

Hardware examples

• Processor
• Printer
• System Unit
• Memory Devices
• Keyboard
• Monitor
• Mouse

Computer System Components

• Computer hardware
• Computer software
• Humanware (user/person)

Computer Hardware

• Internal hardware
• External hardware

Computer Software

• System software
• Application software
• Malicious software
• Programming software

Internal Hardware Components

• CPU
• ROM
• Motherboard
• RAM
• Graphics Card
• Sound card
• CPU fan and heatsink
• Hard Disk Drive, SSD, Memory Stick Micro (M2)
• Network Interface Card

External Hardware Components

• Mouse
• Camera
• Monitor
• Speaker
• Keyboard
• Touchpad

System Software

• Operating System

Application Software

• Examples include word processors, spreadsheets, browsers, etc

Malicious Software

• Includes spyware and malware, and triggers virus alerts

Programming Software

• Used for coding and software development

Users in different sectors

• Healthcare
• Business
• Maritime
• Aviation
• Education

Input Devices

• Devices with the help of which the user feeds data to the computer; creates an interface between user and computer
• They transform the information into a form acceptable to the computer
• Data can be in the form of numbers, actions, words, directions, instructions, etc.
• Computers use their CPU to process this data and deliver output

Input Device Examples

• Computer keyboard (enters symbols, numbers, and characters)
• Mouse (enters commands and directions)
• Joystick
• Optical Mark Reader (OMR)
• Light Pen
• Magnetic Ink Card Reader (MICR)
• Track Ball
• Graphic Tablet
• Scanner
• Microphone
• Optical Character Reader (OCR)
• Barcode Reader

Keyboard

• Christopher Latham Sholes invented the first practical typewriter in 1875
• The keyboard is like a typewriter but with a modern set of arrangements
• An input device that takes letters or characters from the user, processes it, and then shows the output on the monitor screen
• Keyboards have many push buttons referred to as keys
• Keyboards were initially used for typing, but are now used by gamers and editors
• Types available include Flexible, Gaming, Wireless, Membrane, Mechanical, and Virtual keyboards

Types of keys on a computer keyboard

• Alphanumeric keys
• Function keys
• Toggle keys
• Control Keys
• Punctuation keys
• Navigation keys

Mouse

• Initially known as the X-Y Position Indicator for a Display System
• Invented by Douglas Engelbart in 1963 while working at Xerox PARC
• A handheld hardware input device that controls a cursor in a GUI (graphical user interface)
• Used for pointing, moving, and selecting text, icons, files, and folders

Uses of a Mouse

• Move the mouse cursor: The primary function
• Point: Point something out for another user or point to a digital object; to point a gun in a direction to shoot
• Open or execute a program: Moves the pointer to an icon, folder, or another object and clicks or double-clicks to open the document or execute the program
• Select: Lets users select text, files, or highlight and select multiple files at once
• Drag-and-drop: When something selected, it can also be moved using the drag-and-drop method
• Hover: Moving the cursor over objects with hover information helps discover each object's function
• Scroll: When working with a long document or viewing a long web page, you may need to scroll up or down using the mouse wheel or scroll bar

Types of Computer Mouse

• Pointer Mouse
• Gaming Mouse
• Magic Mouse
• Trackball Mouse
• Ergonomic Mouse
• Wired Mouse

Parts of the Computer Mouse

• Wheel: Scrolls up or down the page or menu
• Cable: Connects to USB port on computer
• Left-click: Moves cursor or selects an object
• Right-click: Opens context sensitive menus

Output Devices

• Any peripheral that accepts data from a computer and prints, projects, or reproduces it; output may be audio, video, or hard copy
• Output devices convert computer data to a human-understandable form
• Input is given to the computer using input devices and the computer performs operations on the data and displays output to the user
• Examples include monitors, printers, projectors, speakers, and headphones

Output Devices: Monitor

• Television-like screens that provide the user interface in the form of displaying text, numbers, and images
• Can be monochrome or colored

Output Devices: Speaker

• Can produce verbal output (sound)

Output Devices: Printers

• Produce hardcopy output

Printer classifications

• Character printer
• Line printers
• Page printers
• Impact printers
• Non-impact printers

Character Printer

• Dot Matrix Printers (DMP)
  • Prints one character at a time
  • Produce dotted-output because of the pins on the print head
  • Speed is measured by CpS (Character per second); 50-600cps
  • Produces a lot of noise
  • Uses ribbon as ink

Character Printer: Inkjet Printer

• Non-impact printer
• Quiet when working
• Gives better quality
• Available in black/white and in color

Character Printer: Graphic Plotter

• Used for large format media
• Used for graphs, maps, billboards, or tarpaulin

Line Printer: Drum printer

• Uses powder as an ink
• Available color: Grayscale

Page Printer: Laser printer

• High-end printer
• More expensive than inkjet printers
• Available color: Grayscale

Central Processing Unit (CPU)

• Known as the brain of the computer
• Executes all types of data processing functions
• Saves data/intermediate results/instructions and controls the operation of all parts of the computer
• Facilitates all types of data processing operations
• Handles the operating of all parts of the computer

CPU Components

• Memory or Storage Unit
• Control Unit
• ALU (Arithmetic Logic Unit)

Memory or Storage Unit

• This part of the computer system stores instructions, data, and intermediate results and passes data when required
• It's an internal storage unit, main memory, or primary storage that comes in various speeds, power, and capability
• Primary and secondary memory are the two main types

Primary Memory: RAM (Random Access Memory)

• Volatile and loses its contents if the device is electrically disconnected
• Temporary holding area for data, application program instructions and operating system (OS)
• Referred to as the "waiting room"

Primary Memory: ROM (Read-Only Memory)

• A type of computer memory that is non-volatile and retains its data even when the power is turned off
• Used primarily to store firmware, which is software that is closely tied to specific hardware, like BIOS (Basic Input Output System)
• Used to boot up a computer or other electronic devices
• Cannot be easily written to or modified, and is hence "read-only"

Secondary Memory: Magnetic disk

• Direct access
• Made of rigid materials or symmetric plastic material
• Examples include hard disk and floppy disk

Secondary Memory: Magnetic tape

• Serial access storage medium
• Reels up to 3600 feet made of mylar plastic tape
• Can store large volume of data at low cost

Secondary Memory: Optical Storage

• Information can be written to or written from an optical disk or tape using laser beam
• Also known as “laser disk"
• Examples include CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RW, DVD-R, Blu-ray

Secondary Memory: Solid state storage

• Sometimes called flash memory
• Erasable and re-writable
• Examples include flash drives (pen drives) and memory cards (SD/MMC)

Secondary Memory: Cloud-based Storage

• A type of data storage in which digital data is stored on remote servers accessed via the internet

Control Unit

• Manages the operations of all parts of the computer
• Does not carry out any calculations or comparisons or actual data processing operations
• Facilitates the transfer of data and instructions among other units of a system
• Manages and correlates all the units of the system
• Receives instructions from memory, interprets them, and directs the operation of the system
• Interacts with the Input/output units to transfer data/results from storage
• Does not perform processes or store data

ALU (Arithmetic Logic Unit)

• Arithmetic Section: Executes arithmetic operations (addition, subtraction, multiplication, and division); complex operations are executed iteratively
• Logic Section: Executes logic operations (comparing, selecting, matching, and merging data)