Chapter No.1 - Fundamentals of Computer Sciences

What is Computer?

The Word Computer comes from the word “compute” which, means to calculate. But now a day, computers are also being used for many other purposes else Calculating.

Thus the computer can be defined as:

“It is an electronic device which accept instructions in the form of input and after processing it gives us Information in the form of output.”

Components of Computer

Basically, a computer consists of four components.
Hardware: The physical or tangible parts of computer called hardware. Like Monitor, Keyboard, CPU, Mouse etc.
Software: The set of instructions, that tells the computer, what to do and how to do.
Data: A collection of raw facts and figures is called data, which can include text, numbers, images, audios etc.
User: Computer cannot do anything without its operator.
Information: The processes form of data is called information.

Information Processing Cycle (IPC)

The series of tasks that convert data into information.

Brief History of Computer

The abacus, shown in below, is a calculator; its first recorded use was circa 500 B.C. The Chinese used it to add, subtract, multiply, and divide.

1. In 17th Century BLAISE PASCAL a mathematician and scientist of France developed the first mechanical calculator, which he called the “Pascalins”
2. CHARLES BABBAGE a mathematician of UK in 1822 designed a special type of calculator called “difference Engine” and in 1833 he developed a machine called “ANALYTICAL ENGINE”.
3. Later on American scientists working at Howard University and developed computer between 1937 and 1943 called “Howard Mark-I”.
4. First electronic computer was developed in 1946 at the university of Pennsylvania USA.
5. First Personal computer (PC) was developed in 1981.

Remember

Computers have their roots 300 years back in history. Mathematicians and philosophers like Pascal, Leibnitz, Babbage, and Boole made the foundation with their theoretical works. Only in the second half of this century was electronic science sufficiently developed, to make practical use of their theories. The modern PC has roots back to USA in the 1940s. Among the many scientists, I like to remember John von Neumann (1903-57). He was a mathematician, born in Hungary. We can still use his computer design today. He broke computer hardware down in five primary parts:

1. CPU
2. Input
3. Output
4. Working Memory
5. Permanent Memory

Actually, con Neumann was the first to design a computer with a working memory (what we today call RAM). If we apply his model to current PCs, it will look like this:

Classification of Computers

1. Classification by Size and Power
2. Classification by Data Handling
3. Classification by Purpose
4. Classification by Generation

1. Classification by Size and Power

Supercomputer

The most powerful and fastest computers, designed for complex, specialized tasks like weather forecasting and scientific research.

The first Cray Super Computer was introduced in 1976.

Mainframe Computers

Large, fast, and expensive systems used by big organizations to manage vast amounts of data and support hundreds or thousands of users simultaneously.

Minicomputers (Mid-range)

Smaller than mainframes but larger than micros, used for medium-sized businesses or specialized tasks like data processing.

Microcomputers

Small, affordable computers designed for individual use, including laptops, desktop PCs, and handheld devices. Embedded Systems: Specialized computers integrated into larger devices, such as washing machines, microwaves, and cars, designed to perform specific tasks.

2. Classification by Data Handling

Digital Computers

Process data in discrete form, representing information using binary digits (and). Most modern computers are digital.

Analog Computers

Process continuous data, such as measuring physical variables like voltage, temperature, or pressure.

Hybrid Computers

Combine the speed of analog computers with the precision of digital computers, often used in specialized applications like hospital ICU units for monitoring vital signs.

3. Classification by Purpose

General-Purpose Computers

Designed to perform a wide variety of tasks, such as word processing, browsing the web, and running applications.
Examples include personal computers and laptops.Special-Purpose Computers: Engineered to perform a single, dedicated function efficiently, such as an ATM machine or a traffic light control system.

4. Classification by Generation

1st-5th Generations: Computers are classified based on technology advances, from vacuum tubes to Artificial Intelligence (AI).

Introduction to Personal Computers

Personal computer is also called Microcomputer. Microcomputer was designed to be one person at a time. These are small in size and mainly used in Accounting, Database, Word Processing and Spread Sheet packages etc. Intel Based microcomputer is of two categories:
Old series: 8088, 8086, 80286, 80386, 80486 and 80586
New Series: Pentium I, Pentium II Pentium III, Celeron, AMD, i-Series

Availability of Computers

Branded Computer

These are marketed under a brand name. For example IBM, APPLE, ACER, COMPAQ, HEWLLETT PACKARD (HP), DELL and so on. These are high quality, high cost machines.

UN-Branded Computer

These computers have no name and take the name of the seller. They are normally made in Taiwan or Korea. They are cheap and less reliable machines. PC’s normally come in four sizes & shapes.

• Desktop PC
• Tower PC
• Laptop PC
• Palm Top PC

Characteristics of a Computer

1. Speed

A computer is a very fast device. It can perform in a few seconds the amount of work that a human being can do in an entire year.

2. Accuracy

The accuracy of a computer is consistently high and the degree of accuracy of a particular computer depends upon its design.

3. Diligence

A computer is free from monotony, tiredness and lack concentrations. It can do work for hours.

4. Versatility

Versatility is one of the most wonderful things about the computer. It can do many types of work such as preparing results, bills, letters etc.

5.No.IQ

A computer cannot take its own decision is this regard.

6. No Feeling

Computers have no feelings and no instinct because they are machines.

Components of Computer

Computer has following main components

What is Input?

Input devices /units are used to enter data and instructions into the computer.

Types of Input Devices

1. Keyboard
2. Mouse
3. Microphone
4. Trackball
5. Game Device
6. Webcam
7. Scanner
8. Digital Pen
9. Pen Digitizer
10. Barcode Reader
11. Magnetic Card Reader
12. Biometric Scanner

1. Keyboard

The first input device we will look at is the Keyboard. It is essential part of computer.
IBM standard keyboard has 102 to 106 keys on keyboard. These are four types of keys on the keyboard.

1. Alphabetical keys (A to Z)
2. Numerical Keys (0 to 9)
3. Function Keys (F1 to F12)
4. Special Keys (all sign keys)

2. Mouse

A mouse is peripheral pointing device. It is used for select different items like icons, file and folders in the computer. Mouse help us playing video games and graphic designing in computer. The cursor on the screen follows the motion of the mouse. Buttons on the mouse can be clicked or doubled-clicked to perform various tasks and scroll ball help us to move page up or page down in different computer applications.

3. Microphone

Recording sounds for your computer requires special equipment. Microphones can capture sounds for the air which is good for sound effects or voices. For music the best results come from using musical instruments that is connected directly to the computer.

4. Trackball

A trackball is a stationary computer input device used to control the on-screen cursor by rotating a ball—mounted in a socket with sensors—using a thumb, fingers, or palm. Often described as an "upside-down mouse," it offers precise navigation and ergonomic benefits, as the device remains stationary, saving desk space and reducing arm movement. Instead of moving the whole mouse around, the user rolls the trackball only, which is on the top or side.

5. Game Device

A computer game device is a specialized electronic machine or computer designed primarily for playing interactive digital games, outputting video to a screen, and processing input from controllers. Examples include home consoles (Xbox, PlayStation) connected to TVs, portable handhelds (Nintendo Switch), and specialized gaming PCs.

6. Webcam

A computer webcam (short for web camera) is a digital camera that connects to a computer or laptop, capturing live video and audio for transmission over the internet or recording. Typically using a USB connection or integrated into the screen, they are essential for video conferencing, live streaming, and capturing, often operating on "plug-and-play" technology.

7. Scanner

A computer scanner is an input device that optically scans physical documents, images, or objects, converting them into digital files (like PDF or JPEG) for storage, display, or manipulation on a computer. It acts as a digital photocopier, using light sources and sensors (often CCD) to capture images. The scanner works like a photo copy machine. It captures a whole page and converts it to digital form. The scanner scans text and graphics.

8. Digital Pen

A computer digital pen is an input device that captures handwriting or drawings and converts them into digital data for a computer, tablet, or smartphone. These pens offer a natural, precise alternative to a mouse, enabling digital note-taking, sketching, and handwriting-to-text conversion (OCR) by sensing movement, pressure, and position.

9. Pen Digitizer

A computer pen digitizer (often referred to as a graphics tablet, drawing tablet, or pen tablet) is an input device that allows a user to draw, paint, sketch, or write directly into a computer using a stylus, mimicking the natural experience of using a pencil and paper

10. Barcode Reader

A barcode reader (or scanner) is a hardware input device that captures and decodes information stored in barcode patterns—1D (lines) or 2D (matrix/QR)—converting them into digital data for computers, POS systems, or inventory management. It works by emitting light and measuring the reflection to translate patterns into characters.

11. Magnetic Card Reader

A magnetic card reader (MSR) is a hardware input device that reads data stored on the magnetic stripe of plastic cards, such as credit cards, ID cards, or loyalty cards. It works by detecting magnetic field changes as a card is swiped through a slot, converting this information into digital data for computers.

12. Biometric Scanner

A computer biometric scanner is a hardware device that captures unique physiological or behavioral characteristics of a person—such as fingerprints, iris patterns, or facial features—to verify identity or authenticate access to a computer system, device, or secure facility. It serves as a secure, convenient replacement for traditional passwords, utilizing "something you are" rather than "something you know".

What is Output?

Output is data that has been processed into useful form, now called Information. The output devices are used to receive the results from the CPU in the form of electrical signals and convert them into readable form and their display.

Hard Copy: printed on paper or other permanent media.

Soft Copy: displayed on screen or by other non-permanent means.

Types of Output Devices

1. Monitor
2. LCD
3. LED
4. Speaker
5. Printer
6. Plotter

1. Monitor

To display the result from a computer. A TV like device is called monitor. It is also called Video Display Unit (VDU) or it displays text and graphics objects.
Monitors are basically of two types.

1. Monochrome Monitor

These Monitors are cheap and display only one color.

2. Color Monitor

These monitors display many colors. The resolution of these monitors is measured in Pixels (Picture Elements). More the pixels better is the image displayed on the screen.

2. LCD

LCD stand for Liquid Crystal Display. A liquid crystal display uses charged liquid crystal between sheets of material such as glass or plastic to light up the appropriate pixels to form the image on the screen. LCDs provide a sharper picture than CRTs and emit less radiation. It is also requires less power and takes up less space than CRT.

3. LED

LED stand for Light Emitting Diode. A display can uses LED for the backlight is called an LED display. It consumes less power and is thinner, lighter and brighter than LCD. However, it can be more expensive than LCD. Display screens of laptops and mobile devices use LED backlight technology.

4. Speaker

It is also an output device. It gives us the result or output in the form of sound. Specially used with audio software.

5. Printer

We can see output on a screen or can print out on a paper through a device called printers. Most of the printers produce output in black and white but some can print in colors. Epson, Hewlett Packard is popular printers names. Basically the printers are of these types:

1. Character Printers
2. Line Printers
3. Laser Printer
4. Inkjet Printer

1. Character Printers

Character Printers print a one character at a time. Examples of these are Dot Matrix printer, and the Daisy Wheel Printers etc.

2. Line Printers

Line Printers print one line at time. They are faster than character printers. Examples: Chain Printer, Drum Printers.

3. Laser Printer

A laser printer is a high-speed, non-impact computer printer that produces high-quality text and graphics by using a laser beam to create electrostatic images on a rotating drum. It utilizes dry, powdered toner rather than liquid ink, fusing it onto paper with heat. These printers are favored for fast, high-volume, and cost-effective printing.

4. Inkjet Printer

An inkjet printer is a type of computer printing device that creates digital images or text by spraying microscopic droplets of liquid ink onto paper, plastic, or other substrates. Ideal for high-quality photos and home use, they are popular for producing vibrant colors and fine detail at an affordable upfront cost.

6. Plotter

Plotters are used in Computer Aided Design (CAD) packages. They are used to print high quality graphics. A plotter produces drawing, maps, design, and pictures. These are widely used in science, engineering, and industrial designing.

6. Projector

A projector is an optical device that displays images, videos, or data by shining a light source—often through lenses—onto a screen or surface to create an enlarged, visual representation. Primarily used for presentations, movies, and home entertainment, they can be digital, laser-based, or traditional film/slide units.