Basic Computer Functions and Applications

• Computer usage is ubiquitous and relevant in business, education, politics, and personal use
• A computer is an electronic device that accepts data, processes it according to rules, produces results, and stores them
• Computers are powered by electricity
• Computers are programmable through sets of instructions

Basic Computer Operations

• Input involves feeding data from the external environment, like typing on a keyboard or using a mouse
• Storage is recording data, such as saving documents, photos, or music on a hard drive, memory card, flash drive, or floppy disk
• Processing is data manipulation using a CPU, which performs arithmetic and logical operations
• Output is presenting processed data as information through monitors, printers, and speakers

Computer Applications

• Computers are used in various applications, not just desktop offices
• Financial and Transaction Processing Systems: ATM and POS terminals are examples
• Registration and Billing: Airline ticketing, hotel reservations, enrollment, and utility billing employ computers
• Forecasting and Simulation: Used in weather and flight simulations
• Manufacturing Applications: Computer-Aided Manufacturing (CAM) and Drawing (CAD), robotics, and embedded systems
• Communication Applications: Cellular phones, e-mail, and Internet chat are computer-based
• Transportation: Utilizes auto-pilot and traffic lights
• Educational Applications: Statistics rely on computer-aided instruction, presentation software, and presswork programs
• Military and Law Enforcement: Speed traps, GPRS, and remote sensing satellites use computers
• Recreation: Computers are used in games, movies, MP3 players, and Deep Blue
• Office Productivity: Word processing, presentation software, spreadsheets, desktop publishing, and imaging

Advantages of Computers

• Efficiency: Computers process information rapidly, accurately, and precisely
• Speed: Computers process data quickly
• Consistency: Computers provide consistent output based on given instructions and data
• Reliability: Computers perform complex tasks repeatedly without rest
• Versatility: Computers can perform anything with the proper instructions
• Convenience: Computer systems are user-friendly
• Connectivity/Communication: Most computers can connect to other computers wirelessly
• Storage: Computers store large quantities of data for processing

Disadvantages of Computers

• Violation of Privacy: Personal data stored on computers can be compromised
• Public Safety: Sharing personal data online can make users vulnerable to dangerous strangers
• Impact on Labor Force: Computers replace some jobs, requiring workers to update their skills
• Health Risks: Prolonged computer use can cause health injuries or disorders like computer addiction and technology overload
• Impact on Environment: Computer manufacturing and waste deplete resources and pollute the environment; green computing aims to reduce these effects
• Power Interruption: Dependence on electricity can lead to loss of profit, hardware failure, and data loss

Classification by Age and Components

• Early Computers: Used gears, relays, and mechanical systems
• First Generation: Vacuum tubes and monolithic systems were used
• Second Generation: Transistors and batch systems were implemented
• Third Generation: Integrated circuits and multiprogramming systems were used
• Fourth Generation: Microprocessors/VLSI and personal computing are hallmarks

Classification by Size and Power

• Supercomputers: Largest, fastest type used for high-volume tasks like weather prediction and data processing
• Mainframes: Provide centralized storage and processing for large organizations and critical applications; and is also referred to as "Big Iron"
• Minicomputers: Multi-user computers offering a cost-efficient alternative to mainframes
• Microcomputers: Use a microprocessor as a CPU; personal computers (PCs) are typically used by a single user

Classification by Design

• General-purpose: Perform common computing tasks (e.g., tablet PCs, notebooks, smartphones)
• Special-purpose: Designed for specific tasks with built-in instructions (e.g., microwave ovens, remote controls, industrial robots)

Classification by Function

• Server: Provides data to other computers and can be local (LAN) or wide area (WAN)
• Workstation: High-performance system designed for a single user with advanced graphics capabilities, large storage, and a powerful processor

Other Classifications

• Terminal: Device with a display and keyboard for entering and displaying information connected to a central computer
• Stand-alone/Personal: Desktop or laptop computer used independently without a network connection (LAN or WAN)
• Serial: Single-processor computer executing one instruction at a time
• Parallel: Computer using multiple compute resources simultaneously to solve problems

Personal Computers

• Personal computers include desktops and laptops
• Desktop computers can be upgraded easily and are often cheaper
• Laptop computers are portable but harder to upgrade and also called notebook computers

Other types of personal computers

• Tablet Computers: Use touch-sensitive screens for typing and navigation
• Mobile Phones: Smartphones can perform many computer functions
• Game Consoles: Specialized for video games, but new consoles can browse the internet
• TVs: Smart TVs use applications for accessing online content like Netflix

Early Computers: Gears/Relays and Mechanical Systems

• 2500 BC: The abacus was developed using beads on wires for calculations, and was first created in Mesopotamia, then China
• 1642: Blaise Pascal developed the Pascaline, the first automatic mechanical calculator
• 1671: Gottfried Wilhelm von Leibniz created the Leibniz Calculating Machine, improving Pascal's work

18th and 19th Century Developments

• 1804: Joseph-Marie Jacquard invented the Jacquard Mechanical Loom using punched cards as input
• 1822: Charles Babbage designed the Difference Engine which calculates navigational tables and is known as the Father of Modern Computing
• 1837: Babbage conceptualized Analytical Engine, which is controlled by a program on punched cards
• 1843: Ada Augusta Byron King translated description of analytical engine, dubbed as 1st programmer
• 1854: George S. Boole published Boolean Algebra, forming the basis for computer logic circuits
• 1890: Herman Hollerith and James Power developed the Punched Card Machine for US Census

20th Century Developments

• 1936: Alan M. Turing developed the Turing Machine as a logic and machine intelligence model.

First Generation: Vacuum Tubes and Monolithic Systems

• Computers used vacuum tubes, which were expensive to operate and large
• Vacuum tubes acted as amplifiers and switches to control current
• 1906: Lee de Forest invented the audion, the first three-element vacuum tube
• 1939: Dr. John Vincent Atanasoff and Clifford Berry built the Atanasoff-Berry Computer (ABC), first to use vacuum tubes

1940s Computer Developments

• 1941: Konrad Zuse built the Z3 Electromechanical Relay Computer that was programmed using punched film
• 1943: Alan Turing developed the Colossus for cryptanalysis
• 1944: Howard Hathaway Aiken developed Harvard Mark I (ASCC) using telephone relays and wheels for storing numbers
• 1945: John von Neumann demonstrated the concept of computers having a simple, fixed structure, which is the stored-program technique
• 1946: John W. Mauchly and John Presper Eckert Jr. developed the ENIAC, and began work on the EDVAC.

Continued Computer Implementations

• 1948: F.C. Williams and T. Kilburn invented Manchester Mark I to test CRT memory tube
• 1949: John W. Mauchly and John Presper Eckert Jr. introduced the BINAC with magnetic tape input and internally stored programs
• Cambridge University created the EDSAC, and was the first full-scale stored program computer
• 1950: Eckert-Mauchly Computer Corporation produced the UNIVAC, designed for business applications
• 1954: IBM developed the IBM 650, which was the first mass-produced computer

Second Generation: Transistors and Batch Systems

• Transistors replaced vacuum tubes, making computers smaller, faster, and reliable
• 1947: John Bardeen, William Shockley, and Walter Brattain invented the transistor
• 1955: Bell Labs created TRADIC which was the first computer to use transistors.
• 1959: The BUNCH launched Honeywell 400, which provides a more powerful cooler computer
• IBM launched the batch system within two machines named the, IBM 1401 and IBM 7094

Third Generation: Integrated Circuits and Multiprogramming Systems

• The third generation brought Integrated Circuits to the new platform and was cheaper to produce
• 1958: Jack Kilby designed the first integrated circuits in a computer
• 1963: Digital Equipment Corporation launched the PDP-8, the first successful minicomputer
• 1964: IBM Corporation released the IBM 360, using the concept of multiprogramming
• 1968: BUNCH made B2500/B3500, the first computers to use ICs fully

Fourth Generation: Microprocessor/VLSI and Personal Computing

• Multiple integrated circuits were built on a silicon chip, called the microprocessor or processor
• 1971: Marcian "Ted" Hoff designed the Intel 4004 microprocessor, which combined computer elements on a single microchip
• 1974: Ed Roberts of MITS built the first microcomputer which was the Altair 8800.
• 1975: Steven Jobs and Steve Wozniak under the Apple Corporation developed the Apple I

Late 1970s to 1980s

• 1977: Three mass-market personal computers emerged: APPLE II, Radio Shack TRS-80, and Commodore PET
• 1976: Seymour Cray made Cray I supercomputer, the fastest and most powerful computer of the time
• 1979: Software Arts created VisiCalc, the first business program for personal computers
• 1981: The IBM Corporation developed the IBM PC
• 1984: Adam Osbourne invented the Osbourne-I, which was the first portable computer
• 1985: Period of competition between Apple Inc. and Microsoft, where Apple introduced Macintosh
• 1989: Tim Berners-Lee invented the World Wide Web