Introduction to IT and Computer Systems

• Information technology (IT) uses computer systems/devices to access information, playing a significant role in the workforce, business, and daily activities.

What is a Computer?

• Derived from the Latin "computare" (to calculate), a computer is a programmable electronic device for retrieving, storing, and processing data.
• A computer consists of hardware (processor, memory, etc.) and software (applications, operating systems, etc.).
• Data constitutes unorganized facts and figures, lacking defined patterns or context i.e. "unstructured facts and figures".
• Information is structured, organized, meaningful, and processed data, converted from raw data by a computer.

Functions of a Computer System

• Input: Information enters the computer via devices like keyboards, mice, microphones, cameras, and scanners.
• Processing: The CPU processes information from input devices and memory using programmed instructions.
• Output: Processed information is sent to output devices like monitors, speakers, and printers for user interaction.
• Storage: Temporary (erased on shutdown, like RAM) and permanent (preserved on shutdown, like hard disks, USB drives, and CDs/DVDs) storage components enable computers to store data for later use.

Characteristics of Computers

• Speed: Performs calculations faster and more accurately than humans.
• Diligence: Operates tirelessly for extended periods.
• Accuracy: Low chance of errors in computations/operations.
• Reliability: Consistent output for consistent input.
• Versatility: Capable of performing different tasks with accuracy and efficiency.
• Memory: Stores and precisely accesses millions of records, with capacity measured in Bytes, KB, MB, GB, and TB.
• Automation: Automates tasks following programmed instructions, especially with AI-based technology.

Computer Fundamentals

• A computer electronically stores, retrieves, and processes data based on a program to perform tasks like computing, automation, and data storage.
• Computers help complete tasks such as making documents, sending emails, printing, and editing.
• Data processing converts raw data into meaningful information through input, processing, output, and storage.

Computing Process Phases

• Input: Data is entered using devices like keyboards, mice, cameras, and touchscreens.
• Processing: The CPU processes the input.
• Output: The processed data is shown through devices like screens, videos, audio devices, and printers.
• Storage: Data is kept on the computer or portable devices for future use.
• RAM is used for temporary storage while the computer is running.
• Hard drives are used for permanent storage, even when the computer is off, and examples are USBs and cloud storage.

Elements of a Computer System

• Hardware: Tangible physical components such as keyboards, monitors, and printers.
• Elements of hardware are input, output, processing and mamory hardware.
• Software: Programs or instructions enabling users to perform specific tasks.
• People: Users interacting with the system.
• Procedures: Instructions, written in code, for computer task execution.
• Data: Raw facts and figures entered into the computer.
• Connectivity: Links computers to facilitate information sharing via LAN, Bluetooth, Wi-Fi, etc.

History of Computing

• A computer accepts data/input, processes it, and produces a result.
• Computing means a computer performs any action, from opening an application to editing an image.

Five Generations of Computers

• First Generation (1940-1956): Used vacuum tubes for circuitry and magnetic drums for memory, large, difficult to program, relied on machine language, used punched cards, and had slow operating speed with high power consumption.
• Second Generation (1957-1963): Used transistors, assembly languages (COBOL, FORTRAN), transistors replaced vacuum tubes, smaller and faster, had reduced size but still used punched cards, stored instructions in memory, and integrated CPU, memory, and I/O units.
• Third Generation (1964-1971): Used integrated circuits (ICs/chips), smaller semiconductors increased speed and efficiency, interacted through keyboards/monitors, had an operating system, and became more accessible/affordable.
• Fourth Generation (1970s-Present): Used Large Scale Integrated Circuits (LSIC), i.e. microprocessors, which enabled microcomputers, Very Large Scale Integrated Circuits (VLSIC) replaced LSICs, small computers linked into networks, the internet was born, the development of Graphical User Interfaces (GUIs), including mouses and handheld devices.
• Fifth Generation (1980-Present): Uses AI, parallel processing, superconductors, Ultra Large Scale Integration (ULSI), and programming languages like C, C++, Java, and .Net sophisticated computers like IBM, Pentium, Desktop, Laptop, Notebook, Ultrabook, etc. and parallel processing.

Computer-Based vs Paper-Based Databases

• Computer-based databases use computer software for data storage, organization, and management.
• Paper-based databases use tangible documents like paper records, files, or folders.

Computer Applications in Society

• In Business and Industries: Computers have become essential business tools, used in product creation, marketing, accounting, and administration.
• Communications: Enable efficient communication, research for accessing information and complex analyses, sales and marketing with customer relationship management (CRM) and data management and storage. It enhances product development from concept to launch.
• In Education: Computer systems and tech enhance access to information, interactive learning with simulations and multimedia, distance learning, student assessment (online tests), and skill development. -It: digital skills are crucial for future careers. Benefits in Education: Collaboration, personalized learning, engagement, and accessibility. Challenges in Education: Limited access, distraction, and high costs.
• In Medical Field: Computers are essential for accessible, effective healthcare, offering clearer imaging, more precise treatments, efficient care with electronic health records (EHRs), hospital information systems, personalized medicine.
• Also helps in advancing knowledge such as safe training via data analysis and medical simulations.
• In medicine and healthcare. computers aid in medical research, streamlined healthcare services and enhanced medical imaging techniques.
• In education computers enable online learning platforms, digital resources, and automated grading.
• In finance and banking, computers enable secure online banking, automated trading, and financial modelling.
• For environmental science, computers simulate and analyze large environmental datasets.
• In arts and design, such as graphic design, digital art, and video editing: Computers enhance graphic design, digital art creation, and video editing.
• Used by streaming, gaming, and animation, photos, music, sports, powering analysis, enhancing visualisations and editing in leisure.

Computers in Design, Performance, and Entertainment

• Computer enhance how theatre performances are planned and executed through computer aided design (CAD) software.

Computer Imperfections

• Physical malfunctions, like hard drive failure, disrupt workflows.
• Software bugs can cause crashes/incorrect outputs, lowering productivity; cybersecurity risks involve viruses/hacking that compromise data.
• Dependence on computers is inefficient when systems fail.

Software

• Software can improve music production, motion capture, and choreography via programs like FL Studio, Logic Pro, and DanceForms.

Security

• Cookies are text files which track website visitors.
• Electronic surveillance monitors people, often unknowingly, with technology.
• Identity theft steals personal information to borrow money or make purchases.

Malware

• Spyware steals sensitive information from devices.
• Trojan horses spread through attachments/downloads.
• Direct action viruses infect/modify files.
• Polymorphic viruses change code to avoid detection.
• Ransomware encrypts data requesting payment.
• Rootkits grant remote device control.
• SQL Slammer attacks unpatched servers.
• Code Red displayed "Hacked by Chinese!" on infected pages.

Computer Hardware

• Computer hardware encompasses the physical components comprising a computer system.
• Hardware Overview: Modern systems include components such as the system unit, input/output devices, secondary storage, and communications devices.
  • The System Unit: THe heart of the computer consists of the motherboard with the CPU, RAM and ROM chips.

The Motherboard

• The CPU has the Arithmetic Logic Unit (ALU) and the Control Unit
  • The ALU performs processes arithmetic operations and logical operations

Clock

• The System Clock sends out pulses at regular intervals and helps clock the speed of the computer hardware

Bus Lines

• Electrical data roadways transmit data between the CPU and components.

Memory Chip

• Refers to program and data storage which are temporary or permanent. -RAM, volatile and primarily used for storage, holds instructions and data. -ROM chips store Booting Instructons -CMOS chips are powered by batteries and containg infomation that is flexible. -Cash Memory temporarily stores frequently used data to spped progress up.
• Expansion Slots are sockets for expansion cards and Ports are sockets on the exterior of the unit.

Secondary Storage Hardware

• Secondary storage hardware refers to what permanetly holds data and instructions. Floppy disks are an example of a magnetized platter which store information and hard disks store larger and faster amounts of data.
• Magnetic tape stores backups because it is slow and optical discs make suse of optical technology.

Input Output Devices

• Input devices translate data for computer comprehension whereas output devices produce comprehensible data.

Communication Devices

• Enable the transmission of data via modems and network cards, facilitating internet connectivity.

History of Computer Hardware

• First Generation (1940s - 1950s) consisted of vacuum tubes which ate up electricity, machine language. Used in Examples: ENIAC, UNIVAC.
• Second Generation (1950s - 1960s) transistors made smaller and faster computers, used assembly language and magnetic core memory. Examples: IBM 1401, UNIVAC 1108
• Third Generation (1960s - 1970s) made improvements with integrated circuits or ICs. IBM System/360, PDP-8
• Fourth Generation (1970s - Present) used GUI (graphical user interface). IBM PC, Apple Macintosh, Intel 4004
• Fifth Generation (Present & Future) : AI - machine learning, and quantum computing and personal voice assistants.

Classification of Computer Hardware

• Four types; input, output, memory, and processing devices.
• Input devices can be used by the user to type in input
• Output can display informaton from the computer

Processing Devices

• Central processing unit (CPU): is the computer's "brain" that processes data and Motherboard for connecting the componenets.

Memory (Storage) Devices

• Devices are Random access memory (RAM). Store data for long term or short term. Solid state drive (SSD) use flash memory to store.

Types of Computer Hardware

• Input devices include keyboards, mice, touchpads, scanners, microphones, and barcode scanners.
• Output devices include monitors, printers, speakers, headphones, projectors, Braille readers, and plotters.
• Primary memory which is smaller in size, and is part of the CPU that holds program instructions and results
• Secondary Memory which is stored outside the computer, long term or permanently with discs and solid state drives.
• Tertiary Memory which is rarely used and works automatically.

Communication Hardware

• Communication hardware consists of devices like NICs, modems, switches, routers, hubs, Wi-Fi adapters, Bluetooth Adapters, Access Point (AP), Cellular Modems which facilitate connections between computers, networks and and other tech to achieve easy data transmission.

Computer Software

• Software are the programs that execute in accordance with programmed instructions
• Early days of software, Alan Turing is credited with software development. Tom Kilburn was resonsible for the writing in the 1980's.
• There are system software that help your computer functions and allow other software to work and Applications software that provide help towards the specific tasks.
• There are 4 types of software, Productive software, Device Drivers, OS, which can be modified as use.
• Application software also come in different types such as Graphic Software and presentation software.

Computer Software Generations

First Generation: Programming involved reconfiguring wires and setting dials and switches, where there were programming humans who made little humanly errors. Second Generation: Assembly languages and symbols made processes like abbreviations. Third Generation: Natural languages and compilers became available.

The Phases of a Prototype

• Establish the objective of the purpose
• Define the prototype and its functionality.
• Develope the prototype.
• Next evaluate the prototype and check for errors and improvements that should be done.

Software Prototypes

• Requirments for Engieering
• System Design

Software Process Cycle

• All phases require 4 activities. Software specification, Development design and implementation and software evolution.

1. Waterfall Cycle: Is a very sequential approach with each step being represented and arranged in an order.
2. Sprial: Takes a risk with activites where every process and activity are more focused.
3. Agile: An iterative approach is more flexible and customer friendly to make improvements.
4. Iterative is with repeated cycles to allow improvements with the software.

SDLC Tools

Some Commonly Used SDLC Tools Are

• JIRA, Trelo- Used to manage tasks
• Git- To track the changes in code
• Selenium and JUnit for testing codes like Javacript and Java tests, Dockers, used to perform application inside containers.

Is Program

• Program is the part of instruction on how a computer performs the task
• Ex, Malware or a web browser

Cycles and Steps in Program

• A program is comprised of six phases these are Analysis, Design, Coding, Debugging, Formalizing and Documentation.
• There must be proper logic and test and re runs.

Algorithm

• Is the defined steps made to perform a objective, an example witten down text

Types of FLowcharts

• Swimlane diagrams. for team members .used by proggramers to show contributions
• Basic flowcharts used to display steps

Description Language:

• Diagram using charts that map algrothims and other internal tool to to solve customers issues.

Workflow design

The re is process integration that allows for customer and easy of quality with these processes

Data Flowcharting

• Uses data to show the processes.

Hardware Registers

• Registers are computer memory directly in the CPU that executes data instructions. It hold storages with the data being kept.

Types of CPU Resigters

• Registers can hold the name, sybols and functons of the CPU using memory or operant or the instruction code.

1. Control Resigters, Store information
2. Program Center Resigters to execute and make process in time. 3)Intustrucion Pointers. for similar reasons

Issues with computers using Registers.

1. shifting numbers in tiny space
2. Storage capacity, small space not high in data.
3. Overload, and putting too much will make the computer work slower.

To solve this issues can be solved like

1: Shifting with numbers 2: Ensure that you are program will run smoothly 3: Handle Overload to handle memory issues.

Internet Information

• Internet: Tool for accessing and connecting information
• URL is Unique to each and the website. to access contents on internet for easier finding on the internet.

Application on Internet

• Applications are Email, FTP or File transfer Protocal for uploads.
• Applications for emails and even some app such as messnger
• These programs need internet safety
• Use strong passwords.

Internet Effects

• Internet is is quick for communication which gives access to the world with more sources. and has access with online job.
• Cons is Cyberbullying, Hacking,

Future of internet

Artificial Intelligence (AI) and Advanced Communication.