Essentials of computing

CS25C03
CHAPTER-1
COMPUTERS

▶ A computer is an electronic device that takes input, processes it according to

given instructions, and produces output. It is capable of performing calculations,
storing data, and solving problems with great speed and accuracy.
▶ Computers are one of the greatest inventions of modern science. They have
changed the way people work, learn, and communicate. In today’s world,
computers are an essential part of daily life and play a vital role in the progress of
society.
▶ Computers are made up of hardware and software and are used in almost every
field like education, business, healthcare, and communication. They make our
work easier and quicker.
CHARACTERISTICS OF COMPUTERS

▶ Speed:
▶ Computers execute billions of basic operations per second. The CPU clock (e.g., 3.0 GHz ≈
3 billion cycles/sec) and techniques like pipelining, caching, and parallel execution let
them finish tasks in milliseconds.
▶ Example: Sorting a million numbers or rendering a 4K video frame can complete in
seconds/minutes on a modern machine—far beyond manual capability.
▶ Remember: Speed depends on CPU/GPU power, memory bandwidth, storage speed (SSD
vs HDD), and network latency.
CHARACTERISTICS OF COMPUTERS

▶ Accuracy:
▶ Given correct instructions and reliable hardware, computers produce bit-exact results for integers
and deterministic results for the same floating-point environment.
▶ Caveat: Floating-point math has rounding limits (e.g., 0.1 cannot be represented exactly in binary),
so tiny precision errors can appear—this is normal, not “mistakes.”
▶ Reliability tools: Error-correcting (ECC) RAM, checksums, and validation tests improve accuracy in
critical systems (banking, aerospace).
▶ Automation:
▶ Once a task is programmed, the system runs it without further human effort—on a schedule
(cron/Task Scheduler), on an event (file arrives), or continuously (services/daemons).
▶ Example: Monthly payroll generation, nightly database backups, or sensor-driven alerts in factories
happen automatically and reproducibly.
CHARACTERISTICS OF COMPUTERS

▶ Versatility:
▶ A general-purpose computer can perform many unrelated jobs just by changing software:
word processing, 3D design, video editing, simulations, AI, gaming, web hosting, etc.
▶ Why: The same hardware executes different instruction sequences (programs), so the use-
case is limited far more by software than by the machine itself.
▶ Storage:
▶ Computers store huge volumes of data and retrieve it quickly using a memory hierarchy:
▶ Registers/Cache (nanoseconds): tiny but ultra-fast, inside the CPU.
▶ RAM (micro-nanoseconds): fast, temporary working area.
▶ SSD/HDD (micro-milliseconds): persistent long-term storage.
▶ Cloud/Backup (milliseconds+): durable, remote, scalable.
▶ Example: A laptop can hold millions of documents; cloud stores petabytes for companies
with indexing and search for instant retrieval.
CHARACTERISTICS OF COMPUTERS

▶ Connectivity
▶ Networking allows computers to share data and resources locally (LAN) and globally (internet)
using protocols like TCP/IP, HTTP, and DNS.
▶ Outcomes: Email, video calls, shared documents, online banking, e-commerce, streaming, IoT
devices.
▶ Performance factors: Bandwidth (how much data per second) and latency (how quickly a
message travels) determine user experience.
▶ Multitasking
▶ Operating systems use preemptive scheduling to give the illusion of simultaneity—rapidly switching
the CPU among processes/threads. Multi-core CPUs/GPU actually do tasks in parallel.
▶ Example: You can stream music, download files, compile code, and browse the web at once.
▶ Note: Multitasking has overhead (context switching). Heavy loads need enough RAM/cores to stay
smooth.
 HISTORY OF COMPUTERS

▶ The history of computers is a story of continuous innovation and advancement, moving from simple
calculation tools to today’s highly sophisticated machines. The development of computers can be
understood in different generations:
▶ 1)Early Devices (Before the Modern Computer):
▶ Abacus (c. 3000 BC): The earliest known calculating tool, used in Mesopotamia, China, and other
regions to perform basic arithmetic.
▶ Mechanical Calculators (1600s–1800s):
▶ Pascal’s Calculator (1642): Invented by Blaise Pascal to perform addition and subtraction.
▶ Leibniz’s Step Reckoner (1673): Could perform multiplication and division.
▶ Charles Babbage (1791–1871):
▶ Designed the Difference Engine and the Analytical Engine, considered the first concepts of modern
programmable computers.
▶ Ada Lovelace: Worked with Babbage and is often called the first computer programmer.
 HISTORY OF COMPUTERS

▶ 2. First Generation (1940–1956)

▶ Vacuum Tube Computers: Used vacuum tubes for circuitry and magnetic drums for memory.
▶ Very large, consumed massive power, and produced heat.
▶ Examples:
▶ ENIAC (1945): First general-purpose electronic computer.
▶ UNIVAC (1951): First commercial computer in the U.S.
▶ 3. Second Generation (1956–1963)
▶ Transistors replaced vacuum tubes.
▶ Computers became smaller, faster, more reliable, and energy-efficient.
▶ Used assembly language and early programming languages like COBOL and FORTRAN.
▶ Examples: IBM 1401, IBM 7090.
 HISTORY OF COMPUTERS

▶ 4. Third Generation (1964–1971)

▶ Integrated Circuits (ICs): Many transistors placed on a single chip.
▶ Computers became smaller, more powerful, and affordable.
▶ Development of operating systems allowed multiple applications.
▶ Examples: IBM System/360, PDP-8.
▶ 5. Fourth Generation (1971–Present)
▶ Microprocessors introduced: Thousands of integrated circuits on a single chip.
▶ Led to the rise of personal computers (PCs).
▶ Key Developments:
▶ Apple II (1977) and IBM PC (1981).
▶ Graphical User Interface (GUI), mouse, and user-friendly systems.
▶ Examples: Intel 4004 (first microprocessor), Apple Macintosh (1984).
 HISTORY OF COMPUTERS

▶ 6. Fifth Generation (Present and Beyond)

▶ Based on Artificial Intelligence (AI) and advanced technologies.
▶ Use of parallel processing, quantum computing (experimental), cloud computing, and natural
language processing.
▶ Today’s devices are small (like smartphones) but more powerful than early supercomputers.
▶ Modern advancements include:
▶ Machine Learning, Robotics, Neural Networks.
▶ High-speed internet, IoT (Internet of Things).
▶ Quantum Computers (still developing).
 CLASSIFICATIONS OF COMPUTERS:

▶ Computers can be classified in different ways depending on purpose, size, and data handling. Below are
the main classifications:
▶ 1. Based on Purpose
▶ a) General-Purpose Computers
▶ Designed to perform a wide variety of tasks.
▶ Can handle multiple applications such as word processing, calculations, database management, and
browsing.
▶ Examples: Personal Computers (PCs), Laptops, Smartphones.
▶ b) Special-Purpose Computers
▶ Built to perform a specific task or set of tasks efficiently.
▶ Faster and more reliable for their dedicated function but cannot be reprogrammed easily for other uses.
▶ Examples: Air traffic control systems, Weather forecasting systems, Embedded systems in washing machines
or cars.
 CLASSIFICATIONS OF COMPUTERS:
▶ 2. Based on Data Handling
▶ a) Analog Computers
▶ Work with continuous data.
▶ Measure physical quantities like temperature, speed, and pressure.
▶ Less accurate but useful in scientific and engineering fields.
▶ Example: Speedometer, Analog clock, old scientific instruments.
▶ b) Digital Computers
▶ Work with discrete data (0s and 1s).
▶ Provide high accuracy and are used in almost all modern applications.
▶ Examples: Desktops, Laptops, Tablets, Smartphones.
▶ c) Hybrid Computers
▶ Combine features of both analog and digital computers.
▶ Used in specialized applications where both measurement and calculation are required.
▶ Example: Machines in hospitals that monitor patients (ICU monitors), scientific research computers.
 CLASSIFICATIONS OF COMPUTERS:

▶ 3. Based on Size and Performance

▶ a) Supercomputers
▶ Most powerful computers in terms of speed and data-processing capacity.
▶ Used for highly complex tasks such as weather forecasting, space research, nuclear simulations, and AI modeling.
▶ Example: PARAM (India), Fugaku (Japan).
▶ b) Mainframe Computers
▶ Large and powerful systems capable of handling thousands of users simultaneously.
▶ Used in big organizations, banks, railways, and government sectors for bulk data processing.
▶ Example: IBM Z Series.
▶ c) Minicomputers
▶ Mid-sized computers larger than microcomputers but smaller than mainframes.
▶ Used in medium-sized businesses for tasks like database management and industrial control.
▶ Example: PDP-11, VAX series.
 CLASSIFICATIONS OF COMPUTERS:
▶ d) Microcomputers
▶ Smallest and most widely used type of computers.
▶ Designed for personal use.
▶ Examples: Desktops, Laptops, Tablets, Smartphones.
▶ 4. Based on Generation (Historical Classification)
▶ First Generation (1940–1956): Vacuum tubes.
▶ Second Generation (1956–1963): Transistors.
▶ Third Generation (1964–1971): Integrated Circuits.
▶ Fourth Generation (1971–Present): Microprocessors.
▶ Fifth Generation (Present & Future): Artificial Intelligence, Quantum Computing.
▶ Computers can be classified in multiple ways—by their purpose, how they process data, their size and
performance, and even by their historical generation. From powerful supercomputers to tiny
microcomputers in our pockets, each type has its own role in solving problems and making life easier.
 APPLICATIONS OF COMPUTERS:

▶ Computers have become an integral part of modern life. Their high speed, accuracy, storage
capacity, and ability to process large amounts of data make them useful in almost every field.
Below are the major areas where computers are applied:
▶ 1. Education
▶ Used for e-learning, online classes, and digital libraries.
▶ Helps in computer-based training, simulations, and virtual labs.
▶ Students use them for research, assignments, and projects.
▶ 2. Business and Commerce
▶ Used for accounting, payroll, and financial management.
▶ Online shopping (e-commerce) and digital payments.
▶ Stock market analysis, sales forecasting, and customer data management.
 APPLICATIONS OF COMPUTERS:
▶ 3. Healthcare
▶ Patient record management, hospital databases, and billing.
▶ Diagnostic tools (CT scans, MRI, ultrasound, etc.) are computer-controlled.
▶ Drug research, telemedicine, and robotic surgeries.
▶ 4. Science and Research
▶ Used for space exploration, weather forecasting, and climate studies.
▶ Simulation of scientific experiments and complex calculations.
▶ Data analysis in physics, chemistry, and biology research.
▶ 5. Communication
▶ Email, video conferencing, social media, and instant messaging.
▶ Online collaboration tools for teams.
▶ Global connectivity through the Internet.
 APPLICATIONS OF COMPUTERS:
▶ 6. Entertainment
▶ Watching movies, listening to music, and gaming.
▶ Animation, 3D modeling, and special effects in films.
▶ Streaming platforms and virtual reality experiences.
▶ 7. Banking and Finance
▶ ATM operations, online banking, and mobile banking.
▶ Fraud detection and secure transactions.
▶ Financial data analysis and investment management.
▶ 8. Transportation
▶ Airline and railway reservation systems.
▶ Traffic management and GPS navigation.
▶ Autonomous (self-driving) vehicles and logistics planning.
 Basic Organization of a Computer:

▶ A computer is an electronic device that processes data to produce meaningful information. To perform
this, it follows a structured organization consisting of different units that work together. The main
components are:
▶ 1. Input Unit
▶ Function: Takes data and instructions from the user and converts them into a form that the computer can
understand (binary form).
▶ Examples: Keyboard, mouse, scanner, microphone.
▶ 2. Central Processing Unit (CPU)
▶ The CPU is called the brain of the computer. It controls all operations and consists of three parts:
▶ Control Unit (CU):
▶ Directs the flow of data and instructions between different parts of the computer.
▶ Acts like a supervisor, ensuring tasks are done in the correct sequence.
▶ Arithmetic and Logic Unit (ALU):
▶ Performs arithmetic operations (addition, subtraction, multiplication, division).
▶ Handles logical operations (comparison, decision-making: greater than, equal to, less than).
 Basic Organization of a Computer:

▶ Memory Unit (Primary Storage):

▶ Stores data, instructions, and results temporarily during processing.
▶ Examples: RAM (temporary storage), ROM (permanent storage).
▶ 3. Output Unit
▶ Function: Converts the processed results (binary form) into a human-readable form.
▶ Examples: Monitor, printer, speakers, projector.
▶ 4. Storage Unit
▶ Stores data and information for future use.
▶ Two types:
▶ Primary Storage: RAM, ROM (fast but limited).
▶ Secondary Storage: Hard disk, SSD, CDs, USB drives (large capacity, permanent storage).
 Data Representation:

▶ Data representation in computers refers to the way information (numbers, text, images, audio, video, etc.) is
stored, processed, and transmitted inside a computer system. Since computers work with binary digits (0s
and 1s), all types of data must be converted into binary form before processing. This forms the foundation of
computing and is essential for engineers to understand how information is encoded and manipulated at the
machine level.
▶ 1. Number Systems
▶ Computers rely on different number systems to represent data:
▶ Binary Number System (Base 2):
▶ Uses digits 0 and 1.
▶ Fundamental to computer operations.
▶ Example: 10112=11101011_2 = 11_{10}10112=1110.
▶ Decimal Number System (Base 10):
▶ Used in everyday life.
▶ Computers convert decimal numbers into binary for processing.
 Data Representation:

▶ Octal Number System (Base 8):

▶ Uses digits 0–7.
▶ Compact representation of binary numbers.
▶ Hexadecimal Number System (Base 16):
▶ Uses digits 0–9 and A–F.
▶ Widely used in programming and memory addressing.
▶ Example: 2A16=42102A_{16} = 42_{10}2A16=4210.
 Data Representation:

▶ 2. Representation of Numbers
▶ Unsigned Representation:
▶ Only positive numbers.
▶ Example: 8-bit unsigned binary → values range from 0 to 255.
▶ Signed Representation:
▶ Represents both positive and negative numbers.
▶ Methods:
▶ Sign-Magnitude
▶ 1’s Complement
▶ 2’s Complement (most commonly used).

▶ Floating Point Representation:

▶ Used for real numbers (fractions, very large/small values).
▶ Follows IEEE 754 standard with mantissa and exponent.
 Data Representation:

▶ 3. Representation of Characters
▶ Characters (letters, digits, symbols) are stored as binary codes:
▶ ASCII (American Standard Code for Information Interchange):
▶ Uses 7 or 8 bits.
▶ Example: A = 65 (01000001 in binary).
▶ EBCDIC (Extended Binary Coded Decimal Interchange Code):
▶ Used in mainframes.
▶ Unicode:
▶ Uses up to 32 bits.
▶ Supports worldwide languages and symbols (e.g., English, Hindi, Chinese).
 Data Representation:

▶ 4. Representation of Images, Audio, and Video

▶ Images:
▶ Stored as a grid of pixels.
▶ Each pixel has a color value (binary).
▶ Formats: JPEG, PNG, BMP.
▶ Audio:
▶ Sound waves are sampled and quantized into binary form.
▶ Format: MP3, WAV.
▶ Video:
▶ Sequence of images (frames) with audio.
▶ Formats: MP4, AVI.
 Data Representation:

▶ Importance of Data Representation in Engineering

▶ Ensures accuracy in numerical calculations.
▶ Enables data compression for storage and transmission.
▶ Provides compatibility between different systems.
▶ Forms the basis for computer programming, digital logic design, and data communication.

▶ Data representation in computers is the process of encoding numbers, characters, images, and
sounds into binary form so that computers can store, process, and transmit information efficiently. It
is a fundamental concept in Essentials of Computing for Engineering because it bridges the gap
between human understanding and machine operations.
 Using Spreadsheets for Basic
Operations on Data and Visualization

▶ Spreadsheets (such as Microsoft Excel, Google Sheets, or LibreOffice Calc) are powerful tools
used in engineering and other fields for managing, analyzing, and visualizing data. They
provide a grid of rows and columns where data can be entered, processed using formulas,
and presented in graphical formats.
▶ Spreadsheets are essential computing tools that allow engineers to store, organize, calculate,
analyze, and visualize data. They transform raw data into meaningful information, making
problem-solving and decision-making more effective.
 Using Spreadsheets for Basic
Operations on Data and Visualization
1. Basic Operations on Data
Engineers often deal with large amounts of numerical and tabular data. Spreadsheets simplify
handling through the following operations:
a) Data Entry and Organization
• Data is stored in cells, arranged in rows and columns.
• Labels (headings) make datasets structured.
• Example: Entering marks of students, sensor readings, or experimental results.
b) Arithmetic Operations
• Basic mathematical calculations can be done directly.
• Examples:
•=A1+B1 → Adds two values.
•=A1*B1 → Multiplies values.
•=A1-B1 → Subtracts values.
 Using Spreadsheets for Basic
Operations on Data and Visualization
c) Functions and Formulas
• Spreadsheets have built-in functions for quick operations:
•=SUM(A1:A10) → Adds numbers in a range.
•=AVERAGE(B1:B10) → Finds the mean.
•=MAX(A1:A10) → Finds the highest value.
•=MIN(B1:B10) → Finds the lowest value.
•=COUNT(A1:A10) → Counts numeric entries.
d) Sorting and Filtering
• Sorting: Arrange data in ascending or descending order.
• Filtering: Display only data meeting certain conditions (e.g., marks > 50).
e) Data Cleaning
• Removing duplicates.
• Using Find & Replace.
• Handling missing values.
 Using Spreadsheets for Basic
Operations on Data and Visualization
▶ 2. Data Visualization
▶ Visualization helps engineers interpret patterns and trends in data more easily. Spreadsheets offer several types of charts and graphs:
▶ a) Charts
▶ Bar Chart / Column Chart
▶ Compares quantities across categories.
▶ Example: Comparing marks of students in different subjects.

▶ Line Chart
▶ Shows trends over time.
▶ Example: Plotting temperature readings in an experiment.
▶ Pie Chart
▶ Displays percentages or proportions.
▶ Example: Percentage of budget spent on different resources.
▶Scatter Plot

▶ Shows relationships between two variables.

▶ Example: Stress vs. Strain data in material testing.
 Using Spreadsheets for Basic
Operations on Data and Visualization
▶ b) Conditional Formatting
▶ Highlights cells based on rules.
▶ Example: Marks < 40 appear in red, marks ≥ 90 in green.

▶ c) Pivot Tables
▶ Summarize large datasets.
▶ Example: Average sales per region, total marks per student, etc.

▶ Importance in Engineering (Essentials of Computing)

▶ Helps in data analysis and decision-making.
▶ Reduces manual errors with automated calculations.
▶ Supports graphical representation for presentations and reports.
▶ Useful in lab experiments, project data management, financial analysis, and performance tracking