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• Hardware and software are components of computer systems.

Hardware Categories

• Hardware is made up of physical components.
• Internal hardware is built inside the computer, examples include the motherboard and CPU.
• External hardware is not built into the motherboard and connects to the computer, examples include input and output components.

Input and Output

• Input examples encompass keyboards, mice, and scanners.
• Output examples encompass computer monitors, printers and speakers.

Internal Hardware

Motherboard

• A printed circuit board found in all computers.
• Allows the CPU and other hardware parts to function and communicate together.
• It is a hub where other components connect.
• Components connect to the motherboard via sockets and slots.
• Connectors on the motherboard facilitate connection to daughterboards.

Central Processing Unit (CPU)

• Executes commands from computer programs.
• The Arithmetic Logic Unit (ALU) performs math and logic operations.
• The Control Unit (CU) decodes and executes commands.

Random Access Memory (RAM)

• An internal chip that stores data temporarily when running applications.
• Memory can be written to and read from.
• It is volatile, meaning contents are lost when the computer is shut down.
• Stores data, files, and parts of the operating system in current use.

Read Only Memory (ROM)

• Stores permanent information.
• Often contains configuration data for the computer system, such as BIOS.
• Data on ROM chips cannot be altered and can only be read from.
• Data stored in ROM is not lost when power is turned off.
• ROM is classified as non-volatile memory.

Graphics Card/Video Card/VIDEOGRAPHICS CARD (VGA)

• Allows the computer to send graphical information to a video display, such as a monitor, TV, or projector.
• Connects to the motherboard, often using two connectors.
• Consists of a processing unit, a memory unit (usually RAM), a cooling mechanism (often a heatsink), and a connection to a display unit.

Sound Card

• An integrated circuit board.
• Provides the computer with the ability to produce sounds.
• Allows the recording of sound input from microphone connections.
• Allows the manipulation of sounds stored on the disk.
• Supports FM synthesis and wavetable synthesis.

Network Interface Card (NIC)

• Connects the computer to a network like the Internet.
• Does not allow access to the World Wide Web.
• It can be wired or wireless.
• Each NIC has a hard-coded, unique MAC (media access control) address.

Internal Storage Devices

• Examples include Hard Disk Drives (HDD) and Solid-State Drives (SSD).
• HDDs are magnetic and are a primary method for storing data, files, and most system and application files.
• SSD technology is newer.
• SSDs function the same as HDDs but replace them in many cases.

Software

• General term for programs that control the computer system and process data.
• Two categories of software: application software and system software.

Application Software

• Programs that allows a user to perform specific tasks.

Word Processors

• Used to manipulate text in documents, such as essays or reports.
• Text is entered with a keyboard.
• Software provides tools for copying, deleting, and formatting text.
• Formatting examples: bold, italic, underline, change font size and type.
• Tools include: copy and paste, spell checker, thesaurus, translation, tools to create, edit, save, manipulate text, and import photos or images.

Spreadsheet

• Used to organize and manipulate numerical data (integers, real numbers, dates, etc.).
• Data is organized on a grid of lettered columns and numbered rows.
• The grid is made of cells.
• Cells are identified by column letter and row number.
• Functions include: use of formulas for calculations, produce graphs, can do modeling and hypothetical calculations.

Database

• Used to organize, manipulate, and analyze data.
• Normally made of one or more tables, consisting of rows (records) and columns (fields).
• Functions include: carry out queries on database data and produce reports, add, delete, and modify data in a table.

Control and Measuring Software

• Designed to allow a computer/microprocessor to interface with sensors.
• Measures physical quantities in the real world, e.g., temperature.
• Can control applications like greenhouse control.
• Compares sensor data with stored data and sends out signals to change process outputs.

Apps and Applets

• Short for application.
• Software that runs on a mobile phone or tablet.
• Usually downloaded from app stores.
• Examples: games, complex software for phone banking, GPS, camera facilities, and video and music streaming.

Photo Editing Software

• Allows users to manipulate digital photos stored on a computer.
• Functions include changing brightness, contrast, saturation, removing red eyes, changing facial features, and combining photos.

Video Editing Software

• Allows users to manipulate video to produce edited video.
• Enables the adding of titles, color correction, adding/altering sound.
• Enables rearranging, adding, or removing sections of video and audio clips.
• Enables the applying of color correction, filters, and other video enhancements.
• Enables the creation of transitions between clips in video footage.

Graphics Manipulation Software

• Allows bitmap and vector images to be changed.
• Measured in DPI (dots per inch).
• Higher DPI yields higher the resolution and clearer the picture.
• Disadvantage of higher DPI is larger file sizes.
• Type of editing software depends on the format of the original image.

Bitmap

• Images are made of pixels that contain data about image brightness and color.
• Bitmap graphic editors can change pixels to produce different images.
• Disadvantages: may look distorted and low quality when the bitmap image is enlarged/shrunk, and may result in large file size.

Vector

• Does not use pixels, but manipulates lines, curves, and text to change a stored image.

Systems Software

• Programs that allow hardware to run properly and allow the user to communicate with computer

Computer Language

Machine Code

• A programming language that can be directly understood and obeyed by the computer without translation.
• Different for each CPU, native binary language made of 0 and 1.
• Very difficult to read.

Assembly Level Language

• Also known as assembler language (ASM).
• Low-level programming language for computers and other programmable devices.
• 1-to-1 correspondence between language and machine code instructions.

High Level Language

• More "English-like" language used to write programs.
• Enables programmers to write programs independently of the computer type.
• Closer to human language and less like machine language.
• HLL is translated into LLL by an assembler, compiler, or interpreter.
• Easier to understand and read, but the computer cannot understand it directly.

Compiler

• A computer program that translates programs written in HLL into machine code to be used by the computer to perform tasks.
• The original program is called the source code.
• The code after compilation is called the object code.
• Compiled code can be used again without recompilation.
• Examples of HLL: Java, Python, C++.

Linkers/Link Editor

• Computer program that take one or more object files made by the compiler and combines them into one program that can run on the computer.
• Combines modules made by different programmers on different devices to make a final program.

Device Driver

• Software that enables one or more hardware devices to communicate with the computer's operating system.
• Without a driver, the hardware is unable to work with the computer.
• When hardware is connected via USB, the OS looks for a suitable driver or an error message pops up if a driver is not found.

Operating System

• Software running in the background of the computer system .
• It manages basic instructions and allows users to communicate with the computer.
• It allows loading and running of programs and manages security such as user accounts and passwords.

Utility Software

• Designed to carry out specific tasks on the computer.
• Programs help to manage, maintain, and control computer resources.
• Examples include antivirus software, anti-spyware, fire backup, disk repair, file management, security software, screensavers, disk defragmenters, and encryption/decryption tools.

Analogue and Digital Data

Digital Data

• A computer can only understand data in binary format (0,1).
• Digital data is discrete or discontinuous values, e.g., 1, 4.

Analogue Data

• Data from the real world.
• Physical data that changes smoothly from one value to the next and is continuous.
• Examples numbers with decimals.
• If analogue needs to be sent to a computer it must be converted to digital format using an analogue-to-digital converter (ADC).
• Output from a computer is converted by a digital-to-analogue converter (DAC).

Main Components of a Computer System

• Input devices: Keyboard, mouse, camera, mic, sensor, and scanner.
• Output devices: Monitor, printer, speaker, and projector.
• Secondary storage devices: HDD, SSD, and pen drive.
• Four main internal hardware components.

CPU - Central Processing Unit

• Interprets and executes commands from computer hardware and software.
• Previously made of discrete components and many small integrated circuits; now, due to modern manufacturing, it is a MICROPROCESSOR.

Microprocessor

• A single integrated circuit at the core of most PCs and found in household devices and equipment where control and monitoring are needed.
• Examples washing machines, microwaves, dishwashers, and fridges.

CPU Components

• Control Unit (CU) controls input and output devices, extracts instructions from memory, decodes and executes them, and calls on ALU if necessary, communicating with both ALU and memory.
• Arithmetic and Logic Unit (ALU) carries out calculations and logical decisions.
• Memory Unit is the principal storage of the computer for all data and instructions needed.

Internal Memory (RAM N ROM)

• RAM is a temporary, volatile memory device that can be can be written to and read from.
• RAM is used to store data, files, programs, and parts of the operating system.
• Its size can be increased to improve operational speed.
• ROM is a permanent, non-volatile memory device that can only be read-only and data stored cannot be altered.
• ROM is used to store BIOS and other data needed at start up.
• ROM contains configuration data for the computer system.
• ROM contains the BOOT FILE that tells the computer what to do when it first starts up.
• ROM is often called BIOS (basic input/output system).
• When the computer turns on, BIOS carries out a hardware check to see if all devices are present and functional.
• Then BIOS loads the OS into RAM.
• BIOS stores the date, time, and system configuration in a non-volatile chip called a CMOS (complementary metal oxide semiconductor), which is powered by a battery.

Input Devices

• Hardware that allows data to be entered into a computer with manual entry or direct data entry via a sensor.
• Make input into a form the computer understands, such as mouse movements that move the cursor.
• Analog to digital conversion (ADC) is sometimes needed, for example, converting sound from a microphone.

Output Devices

• Computer processes data and outputs it to a device so humans can see the results.
• Provides data in a human-understandable form through text or images.
• Some devices are both input and output devices, like touch screens and DVD writers/players.
• Most devices are either one or the other.
• Similarities: Both provide an interface for users to interact with the computer or hardware with a power source

Backing Storage

• Main memory in a computer involves RAM and ROM.
• Backing storage is meant to permanently store large amounts of data.
• Examples, the internal hard disk drive (HDD) or solid-state drive (SSD).
• Main internal storage: contains where application software, disk OS, files, text, photos and music

Data Access

• Access time/rate: speed to open files and data transfer
• Save from RAM to HDD (backing storage)
• RAM contents lost computer powers down and ROM readable only
• Backing devices maintain storage when powered down
• Data speeds in RAM of ROM is extremely fast but backing is slow to access in RAM or ROM
• RAM of ROM is read directly by the CPU

Operating System Sys

• Control to input output a backing device
• Supervised loading on application storage

User Interfaces

Command Line Interface (CLI)

• Requires the user to type instructions to choose options from menus, or to open software.
• Requires extensive commands of what to save or load
• Windows CLI command prompt
• Advantages
  • If the user knows the correct command it's the fastest way to communicate
  • Needs less memory than other interfaces
  • Doesn't use much CPU to process
• Distadvantages
  • Confusing for those who haven't used it
  • Commands need to be exact and specific
  • Starting over when messing up instructions
• Comp config settings take a lot of altering

Graphical Use Interface

• Allows interaction with icons instead of typing commands
• Select icons to execute commands in GUI and do not need to type
• Advantages
  • No commands needed to be memorized saving time
  • Icons help visually aid the process
• Disadvantages
  • Need more complex operating systems requiring slower commands

Dialogue Based User Interface

• Relies on human voice to give commands to computer system
• Use of voice to measure temp, lighting

Gesture Based User Interface

• Using body movement to guide data with hands eyes and feet
• Captures an image by comparing with saved gestures

Types of Computers

Desktop

• Monitors keyboards and cpu that are not portable
• Spare parts and standardized connections provide a lower cost

Advantages

• Better CPU power limited size restraints
• Power consumption not critical

Disadvantages

• Have to copy files externally

Laptop

• Combines the monitor's DV unit and system together

Advantages

• Portable with no wires and consumes low power

Disadvantages

• Battery life can be limited requiring cary adaptors

Smartphone

• Android and windows OS and WIFI/Cell network

Advantages

• High definition displays

Tablet

• Touch Screen activation with stylus and finger tips

Advantages

• Switches on no quick for OS
• Touch Screen is easy without DV output
• Use if standard applications with not over generating or high performance

Disadvantages

• Supports less files and programs
• Can be expensive if the cellular network is used frequently

Emerging Tech- Artifical Intelligence

• Carries out tasks requiring intelligence and language with recognizable faces

Impacts

• Al Able to carry out bomb disposals with high safety
• Faster development can lead to jobloss for AI skills

Extended Reality

• Combines real and virtual environment with technology
• Entertainment favorites can be seen and interacted at home
• Users can experience through a phone screen
• Healthcare can build 3d of patients diagnoses