Introduction to Computers

INTRODUCTION TO BASIC COMPUTERS

SESSION 1

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LEARNING OBJECTIVES

• By the end of this session, you should be able to:
• Define computer
• Explain the history of computer
• Outline characteristics of computer
• Identify types of computers according to size, generation, purpose/function, technology
• Identify structure/anatomy of computer (input, CPU, and output)
• Identify components of a computer (Hardware and Software)
• Explain types of computer software
• Explain types of computer hardware (processing, input, output storage
• Perform computer device connections

Perform computer booting (cold and warm booting) Manage folders and files (create, rename, delete, restore, copy, move, search, organize and transfer from computer to removable storage devices) 2

– What is a Computer?

• Computer is an electronic device used to process data.
• Computer can convert data into information that is useful to people.

OR

Computer: is an electronic device that takes data, stores it, processes that data and produces information.

Computer: is a machine or device which accepts data in one form and processes it to produce an output of information.

• Data: can be defined as unprocessed facts/Raw facts .

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The history of Computer

Mechanical era: In the 19th century, Charles Babbage designed the analytical engine, a programmable mechanical computer, and Ada Lovelace wrote the first algorithm for it.

First electronic computers: The ENIAC, considered the first programmable electronic computer, was completed in the 1940s.

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The History of Computer cont.…

• 1. First Generation (1940–1956) – Vacuum Tubes:
• Used vacuum tubes for processing.
• Very large, consumed a lot of power, and produced much heat. Programming was done in machine language.
• Example: ENIAC, UNIVAC I.
• 2. Second Generation (1956–1963) – Transistors:
• Replaced vacuum tubes with transistors
• Smaller, more reliable, and faster.
• Used assembly language.
• Example: IBM 1401.

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The History of Computer cont…

• 3. Third Generation (1964–1971) – Integrated Circuits (ICs):
• Used ICs (multiple transistors on a chip).
• Increased processing speed and efficiency.
• Used high-level languages like COBOL, FORTRAN.
• Computers became more accessible to businesses.
• 4. Fourth Generation (1971–1980) – Microprocessors:
• Introduced the microprocessor (entire CPU on a single chip).
• Rise of personal computers (PCs).
• Increased power, speed, and storage.
• Example: Intel 4004, Apple I, IBM PC.

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The History of Computer cont…

5. Fifth Generation (1980-Present) – AI & Advanced Technologies:

This era is characterized by the rise of personal computers, the internet, and the integration of artificial intelligence and other advanced technologies.

In this Modern era: Computers have become smaller and more powerful, evolving into laptops, smartphones, and wearable devices.

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CHARACTERISTICS OF A COMPUTER

THE TWO PRINCIPAL CHARACTERISTICS OF COMPUTER ARE:-

• A computer responds to a specific set of instructions in a well-defined manner.
• A computer can execute a pre-recorded list of instructions (a program).

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Other Characteristics are:

SPEED : Computer can perform millions of instructions per second..

ACCURACY : Since Computer is programmed, so what ever input we give it gives accurate results.

• STORAGE : Computer can store mass storage of data with appropriate format.
• DILIGENCE : Computer Doesn’t get tired or lose concentration.
• VERSATILITY : Computer can perform different types of tasks at the same time.
• NO IQ : Computer does not work without instruction.
• NO FEELING : Computer does not have emotions, knowledge, experience
• AUTOMATION: Computer Works automatically after programming.

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CLASSIFICATION OR TYPES OF COMPUTERS

• We can classify types of computers based on the following criteria:-
• Types of computer Based on size
• Types of computer Based on generation
• Types of computer Based on purposes/function
• Types of computer Based on Technology

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TYPES OF COMPUTER BASED ON SIZE

• Supercomputer
• Mainframe
• Minicomputer
• Workstation
• Microcomputer

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Types of computer based on size cont.…..

1. Supercomputer

It is Extremely fast, used for scientific simulations, weather forecasting and space exploration.

• It is Very accurate
• It has High processing speed
• Can tackle complex tasks such as breaking codes and modeling worldwide weather system.
• An example of supercomputer: IBM Deep Blue

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Picture of a Supercomputer

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1.Types of computer based on size cont.…

• 2. Mainframe
• These are the very largest computers; they can occupy more than one room.

For example: IBM 370, S/390.

A powerful multi-user computer capable of supporting many hundreds or thousands of users simultaneously like ATM Transactions.

• They are:
• Large in size
• Expensive due to high cost of production
• High storage capacity and high processing speed

Used in organization to process a bulk of information Generally used by large businesses to provide centralized storage, Processing and management for large amounts of data.

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Picture of a Mainframe computer.

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1.Types of computer based on size cont.….

• 3. Minicomputer
• A multi-user computer: Smaller than mainframe but more powerful than Micro-computer.
• computers that are capable of supporting from 10 to hundreds of users simultaneously.
• These are large powerful machines typically serving a network of simple terminals.
• Example of minicomputer; Digital Alpha, Sun Ultra, HP 3000 series, IBM AS/400,PDP series.
• Very powerful and expensive
• Used in medium scale organizations where it is too expensive to use mainframe computers

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1.Types of computer based on size cont.…

4. Workstation

Powerful desktop computers designed for specialized tasks such as medical imaging. Such tasks require a lot of processing speed.

• It is a single-user computer
• They have the power to handle complex engineering applications.

They use the UNIX, or sometimes NT, operating system.

It is like a personal computer, but it has a more powerful microprocessor and a higher-quality monitor.

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1.Types of computer based on size cont.…

• 5. Mini Computers
• Medium-sized computers that fall between microcomputers (like PCs) and mainframes.

Designed to support multiple users simultaneously.

Commonly used in small to medium-sized organizations for tasks like database management, business processing, and departmental computing.

Key Features:

• Multi-user support
• Multi-tasking capability
• Less powerful than mainframes but more powerful than personal computers
• Used in labs, schools, factories, and business departments
• Examples:

PDP-11

• IBM System/3
• VAX series by DEC

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2. Types of computer based on Generation

First Generation (1940–1956)

Second Generation (1956–1963)

Third Generation (1964–1971)

Fourth Generation (1971–Present)

• Fifth Generation (Present and Beyond)

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3.Types of computer based on Purposes

General purpose computer is designed to solve wide variety of problems. Examples of general purpose computer are Pcs

Tablets

Special purpose computer is designed for particular job only. Examples of special purpose computer are :- ATM, Petroleum pumps, Traffic lights, Programmable pocket calculator, Weapons guidance system, Medical equipment computers . Eg CT Scan, Digital cameras 20

4. Types of computer based on Technology

Analog Computers: Use continuous data and are often used for scientific and engineering applications where measurements are involved.

Digital Computers: Use discrete data and perform operations using binary code (0s and 1s). Most modern computers are digital.

Hybrid Computers: Combine features of both analog and digital computers. They can process both continuous and discrete data 21

The Parts of a Computer System

• A complete computer system includes four distinct parts:
• Hardware
• Software
• Data
• User

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HARDWARE

A computer's hardware consists of electronic devices; the parts that you can see and touch. (Tangible parts of computer) 23

SOFTWARE

Software – also called programs – consists of organized sets of instructions for controlling the computer. Or Refers to a Set of instructions that tells computer what to do/ how to perform a certain task.

Some programs exist for the computer's use, to help it manage its own tasks and devices.

Other programs exist for the user, and enable the computer to perform tasks for you, such as creating documents.

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DATA

Data consists of raw facts, which the computer can manipulate and process into information that is useful to people.

• USERS

People are the computer's operators, or users.

Some types of computers can operate without much intervention from people, but personal computers are designed specifically for use by people.

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Types of Hardware

• A computer's hardware devices are categorized as follows:
• Processor
• Memory
• Input and output (I/O) devices
• Storage devices

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The CPU (PROCESSOR)

The processor is also called the central processing unit (CPU). It manages all devices and performs the actual processing of data.

The procedure that transforms raw data into useful information is called Processing. This function is divided between the computer's processor and memory.

The CPU consists of one or more chips attached to the computer's main circuit board (the motherboard).

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Memory

Memory also consists of chips attached to the motherboard.

Memory holds data and program instructions as the CPU works with them. This memory is called Random Access Memory (RAM).

• The CPU can find any piece of data
• in RAM, when it needs it for processing.
• RAM is volatile, meaning it holds data
• only when the power is on. When the power
• is off, RAM's contents are lost.

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How Memory is Measured

The smallest usable unit of measure for memory is the byte – the amount of memory required to hold one character, like the letter A or the numeral 2.

• Computers work with larger chunks of data, measured in multiple bytes, as shown below:
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• Byte

Input and Output Devices

Input devices accept data and instructions from the user or from another computer system. The keyboard, mouse, Scanner, Microphone, Touch Screen, Joysticks and Web-Cam are examples of input devices.

Output devices return processed data back to the user or to another computer system. The printer, monitor, speaker, headphones, Projectors and plotters are examples of output devices Communications devices (such as modems and network interface cards) perform both input and output, allowing computers to share information.

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Storage Devices

• Storage devices hold data not currently being used by the CPU.
• Examples of Storage devices includes
• Floppy disk drive
• Hard disk drive
• CD ROM drives
• DVD ROM drive

Blue Ray Disk

• USB Flash Drive
• SD cards

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What is Software?

Software is a set of instructions that tells the computer how to do certain tasks. A set of instructions is often called a program.

When a computer is using a particular program, it is said to be running or executing the program.

• There are two most common types of software:-
• System software and
• Application software.

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System Software

System software exists primarily for the computer itself, to help the computer perform specific functions.

One major type of system software is the operating system (OS). All computers require an operating system.

• The OS tells the computer how to interact with the user and its own devices.
• Common operating systems include Windows, the Macintosh OS, OS/2, and UNIX .

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Application Software

Application software tells the computer how to accomplish tasks the user requires, such as creating a document or editing a graphic image.

• Some important kinds of application software are:
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Differences between System software and application software

PURPOSE: System Software manages hardware, provides a platform for other software, while Application software perform specific task for the user like writing document.

USER INTERACTION: System software does not interact directly with users i.e runs in the background, while Application software interact with user through a user interface.

DEPENDENCY: System Software can operate independently and is necessary for the computer to run, While Application Software relies on system software to function.

EXAMPLES: Operating systems (eg. Windows, MacOS, Linux), While Application Software are like word processor, VLC, Chrome, Adobe 37

Computer device connections

• Connect mouse, keyboard, and USB devices via ports.
• Connect printer via USB or network.
• Use HDMI/VGA for external monitors.
• Ensure drivers are installed.

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Computer Booting

• Cold Booting: Turning on the PC from shutdown.
• Warm Booting: Restarting the system

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Management of Folders and Files

• Create: Right-click → New → Folder

Rename: Right-click → Rename

Delete: Right-click → Delete (goes to Recycle Bin) – Restore: Open Recycle Bin → Right-click → Restore Copy/Move: Right-click → Copy/Cut → Paste – Search: Use File Explorer or Search bar Organize: Use folders, sort by name/date/type Transfer: Use USB drive or SD card

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Any question

• ?

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