Computer 1

Computer: An electronic data processing device; accepts, stores, processes data, and
outputs information.
Five Functions:
1. Takes data as input
2. Stores data/instructions in memory
3. Processes data → useful information
4. Generates output
5. Controls all steps

Advantages of Computers
 High Speed – Millions of calculations per second.
 Accuracy – Error-free if input is correct.
 Storage Capability – Stores huge data (text, images, audio, video).
 Diligence – No tiredness, boredom, or monotony.
 Versatility – Can perform multiple tasks (scientific problem → games).
 Reliability – Long-lasting, easy to maintain.
 Automation – Executes tasks automatically once programmed.
 Reduced Paperwork & Cost – Digital records lower expenses and speed up processes.

Disadvantages of Computers
 No I.Q. – Cannot make independent decisions.
 Dependency – Fully dependent on human instructions.
 Environment – Needs dust-free, proper conditions.
 No Feelings – Cannot judge based on emotions/experience.

Computer – Applications
 Business: Payroll, budgeting, sales analysis, forecasting, employee database, stock
maintenance
 Banking: Online accounting, balance check, deposits/withdrawals, ATM services
 Insurance: Database of policies: dates, installments, maturity, interests, benefits,
bonuses
 Education: CBE (Computer Based Education), student performance databases, computer
literacy
 Marketing: Advertising, home shopping via computerized catalogs
 Healthcare: Patient records, diagnosis (ECG, EEG, CT, Ultrasound), drug info, surgery
 Engineering Design: CAD (Computer Aided Design), structural, industrial, architectural
engineering
 Military: Missile control, communication, planning, smart weapons
 Communication: Email, chatting, Usenet, FTP, Telnet, video conferencing
 Government: Budgets, tax computation, voters’ list, PAN cards, weather forecasting
Computer – Generations
First Generation (1946–1959) – Vacuum Tube Based
 Main Component: Vacuum tubes, invented by Sir John Ambrose Fleming, served as the
primary processing and memory component.
 Size & Power: Occupied entire rooms, consumed a lot of electricity, and produced
massive heat.
 Memory & Input/Output:

 Magnetic drums were used for memory storage.

 Data input through punch cards and paper tape.
 Output was printed on paper.

 Performance: Faster than humans but highly unreliable due to frequent vacuum tube
failures.
Advantages:

 Performed faster than manual calculations.

 Capable of processing larger amounts of data compared to human effort.
 Laid the foundation for future generations of computers.

Disadvantages:

 Extremely large and required huge cooling systems.

 Very costly; affordable only by governments and large institutions.
 Prone to frequent breakdowns due to tube burnout.

Famous Computers:

 ENIAC (1946): First general-purpose electronic computer, used for U.S. Army missile
calculations.
 EDVAC (1949): Introduced the concept of stored programs.
 UNIVAC I (1951): First commercial computer for businesses and government.
 IBM 701 (1952): IBM’s first large-scale scientific computer.

Second Generation (1959–1965) – Transistor Based

 Main Component: Transistors, invented in 1947 by John Bardeen, Walter Brattain,
and William Shockley, replaced vacuum tubes.
Features:

 More compact, faster, and reliable than vacuum tube computers.

 Consumed less electricity and produced less heat.
 Programming languages COBOL (business use) and FORTRAN (scientific computing)
were introduced.

Types of Transistors:

 Bipolar Junction Transistor (BJT): Amplifies or magnifies electrical signals.

 Field Effect Transistor (FET): Controls current using an electric field; widely used
in amplification and switching.
Advantages:

 Much smaller than vacuum tube computers.

 Faster processing speed, operating in microseconds.
 Consumed less electricity and produced less heat.
 More reliable; storage through magnetic core memory, magnetic tape, and disks.

Disadvantages:

 Still produced heat (though much less than vacuum tubes) and required cooling.
 Development and maintenance costs were still high.
 Machines were still room-sized and not yet for personal use.

Applications:
Used in business data processing, scientific research, military, and engineering tasks.

Third Generation (1965–1971) – Integrated Circuit (IC) Based

 Main Component: Integrated Circuits (ICs), invented by Jack Kilby, combined
multiple transistors, resistors, and capacitors into one chip.
How ICs Work:

 Transistors inside ICs acted as switches or amplifiers.

 Circuits were etched on silicon wafers through photolithography.
 Allowed compact, reliable, and efficient designs.

Types of ICs:

 Analog ICs: Process continuous signals (e.g., amplifiers, voltage regulators).

 Digital ICs: Handle discrete signals (e.g., processors, logic circuits).
 Mixed-Signal ICs: Combine analog and digital functions (used in communications).

Applications:

 Telecommunications: Mobile networks, Wi-Fi, and routers.

 Automotive: Used in safety systems like collision avoidance.
 Healthcare: Found in MRI, CT scanners, and diagnostic devices.
 Industrial Automation: Used to control manufacturing processes.

Advantages:

 Smaller in size, reliable, and energy-efficient.

 Enabled faster processing and greater storage capacities.
 Supported broader adoption across industries.

Fourth Generation (1971–1980) – Microprocessor Based (VLSI)

 Main Component: Microprocessors, made possible through Very Large-Scale
Integration (VLSI) technology.
Features:

 Highly compact, affordable, reliable, and faster than previous generations.

 Introduced portable computers and more advanced programming languages.
  Made personal computers accessible to schools, businesses, and households.

Types/Models of Computers:

Personal Computers (Microcomputers):

 Apple I (1976): Designed by Steve Wozniak and marketed by Steve Jobs; targeted
hobbyists.
 Apple II (1977): More advanced and accessible, widely adopted in homes and
schools.
Minicomputers:
 DEC PDP-11/70: High-end system with improved memory and processing.
 VAX-11/780 (1977): 32-bit superminicomputer with broad applications.
 HP 3000 Series: Designed for business and commercial applications; highly
reliable.

Fifth Generation (1980–Present) – ULSI Microprocessor & AI

 Main Component: ULSI (Ultra Large-Scale Integration) microprocessors with
millions of transistors on a single chip.
 Features:

 Focus on parallel processing and artificial intelligence (AI).

 Capable of highly advanced computations and robotics applications.
 Supported high-level languages such as C, C++, Java, and .NET.

Advantages:

 Extremely small, powerful, and energy-efficient.

 Emphasis on machine learning, AI, and automation.
 Foundation for modern computing, including quantum and AI systems.

Computer Fundamentals
The study of computer basics, including structure, function, and use.

Key Topics:

 Introduction to computers.
 Components: CPU (ALU, CU), memory, storage devices.
 Input/output devices.
 Types of software and operating systems.
 Basics of computer networks.

Advantages of Computers:

 Extremely fast and efficient in handling tasks.

 Large data storage capacity.
 Automation of repetitive and complex processes.
 Enhanced communication through email, social media, and networking.
  Easy access to vast knowledge and resources.
 Improves decision-making, education, business operations, and entertainment.

COMPUTER TYPES

PC (Personal Computer)

 Single-user system

 Based on microprocessor

 Used for word processing, internet browsing, entertainment

Workstation

 More powerful than a PC

 Used for engineering, CAD/CAM, software development, publishing

 High-resolution graphics, larger memory

Mini Computer

 Multi-user, supports up to hundreds of users

 Smaller and cheaper than mainframes

 Example: PDP-11

Mainframe

 Very large, very powerful systems

 Support hundreds/thousands of users simultaneously

 Used in banking, airline reservations, government agencies

Supercomputer

 Extremely fast and powerful

 Used for weather forecasting, nuclear research, simulations, data-intensive research

 Example: Cray supercomputers

COMPUTER COMPONENTS & BASIC OPERATIONS
A computer performs 5 basic operations:

1. Input Data – receiving information through input devices

2. Store Data – keeping instructions and data in memory

3. Process Data – CPU processes information into useful output

4. Output Information – sending information to output devices

5. Control Workflow – CPU directs all other units

 CPU (Central Processing Unit)– Brain of the computer

 Memory Unit – stores instructions, data, and intermediate results

 Control Unit – directs and coordinates operations

 ALU (Arithmetic Logic Unit) – performs calculations and logical operations

INPUT DEVICES

 Keyboard – most common input device

 Typing keys (letters & numbers)

 Numeric keypad (for numbers/calculations)

 Function keys (F1–F12 for shortcuts)

 Control keys (arrows, Home, End, Ctrl, Alt, Esc)

 Special keys (Enter, Shift, Caps Lock, etc.)

 Mouse – pointing device, controls cursor on screen

 Joystick – used mainly in CAD and games
 Light Pen – pen-like device for drawing/selecting on screen
 Trackball – ball-based pointing device used in laptops
 Scanner – converts paper documents/images into digital form
 Digitizer – converts graphics/pictures into digital input (used by designers)
 Microphone – inputs audio
 MICR – used in banks to read cheque (Magnetic Ink Character Recognition)
 OCR – Optical Character Recognition, converts printed text to digital
 Barcode Reader – scans product codes
 OMR – Optical Mark Reader, used for checking exam answer sheets
OUTPUT DEVICES

 Monitors (Visual Display Units)

 CRT – bulky, high power consumption

 Flat Panel (LCD, LED, Plasma) – slim, low power use

Printers

Impact Printers

 Dot Matrix – low cost, noisy, poor quality

 Daisy Wheel – high quality, slow

 Line Printers (Drum & Chain) – very fast, used for bulk printing

Non-impact Printers

Laser – high speed, high quality, expensive

Inkjet – high quality, slower, costly per page

INTERNET VS INTRANET

Internet
 Global network, accessible to everyone
 Public, less secure

Intranet
 Private network, only for organization members
 Safer, restricted access

Similarities
 Use TCP/IP, web browsers, instant messaging
NOTSssssss
1960 - internet
1957 - sputnik satellite
January 01 1983 - exact birth-date of internet

Rankings in usage of internet

 1st - China
 2nd - India
 3rd - USA

1997 - WiFi came

IOT
 smarter than internet
 Internet of Things
Internet
 a group of computer systems connected from all around the world.

Uses of internet
 Email - formal sending of messages
 Webchat - chat room
 World wide web - most popular information
 Internet telephony - converts analog speech impulses into digital
 E-commerce - online business activities
 Video conferencing - use of voice and images

Web 1.0
 1st release
 Disorganized
 emerged with the invention of internet
 read only

Web 2.0
 late 1990s-early 2000s
 emerged during internet boom
 fb, twitter, YouTube
 read/write

Web 3.0
 still in developing/progress
 promises to bring more personalized and intuitive experiences
 still a vision
 read/write/own