CHAPTER ONE The History of Computers

CHAPTER ONE The History of Computers The History of Computers –Chapter Overall Objective At the end of this chapter, the student will be able to discuss the history and terminology of computers At the end of this chapter, the student will be able to discuss the history and terminology of computers

The History of Computers SPECIFIC OBJECTIVES SPECIFIC OBJECTIVES 1.Discuss the history of computers 2.Understand how a microcomputer works 3.Understand the binary number system 4.Understand how data is stored in memory 5.Understand the ethical responsibilities of the programmer

The History of Computers Sections 1.1 – 1.5 Sections 1.1 – 1.5

The History of Computers Section 1.1 Mechanical Devices Section 1.1 Mechanical Devices –Blaise Pascal - mathematician Mechanical calculating device using gears like a clock - Pascaline Mechanical calculating device using gears like a clock - Pascaline Due to manufacturing problems, never got device to work Due to manufacturing problems, never got device to work

The History of Computers

Section 1.1 Mechanical Devices Section 1.1 Mechanical Devices –Gottfried Wilhelm - mathematician 17th century 17th century Mechanical device to add, subtract, multiply and divide - Stepped Reckoner Mechanical device to add, subtract, multiply and divide - Stepped Reckoner Used a cylindrical wheel and a movable carriage Used a cylindrical wheel and a movable carriage Unreliable because device would jam Unreliable because device would jam

The History of Computers

Section Mechanical Devices Section Mechanical Devices –Charles Babbage Difference Engine Difference Engine To be used by ship navigators (navigational tables were inaccurate) To be used by ship navigators (navigational tables were inaccurate) Never built but was the ideas that led to the Analytical Engine Never built but was the ideas that led to the Analytical Engine

The History of Computers

Section Mechanical Devices Section Mechanical Devices –Charles Babbage Analytical Engine Analytical Engine –Tried to use punch cards to store information –Thought the machine would be able to think like a human brain but it did not –Model for the modern computer

The History of Computers Section Electro-mechanical devices Section Electro-mechanical devices –US Census officials in 1880 took 9 years to compile the census information –Hermann Hollerith Tabulating machine that used electricity not mechanical devices Tabulating machine that used electricity not mechanical devices –Worked better because used electricity rather than mechanical gears Used punch cards to represent census information (male, female, age, etc) Used punch cards to represent census information (male, female, age, etc) Very successful Very successful –Next census took only 6 weeks to calculate

The History of Computers

Section Electro-mechanical devices Section Electro-mechanical devices –Mark I Developed by IBM and Harvard University Developed by IBM and Harvard University Used mechanical telephone relay switches to store information and accept data from punch cards Used mechanical telephone relay switches to store information and accept data from punch cards Very large Very large –51 feet in length and 5 tons –750,000 moving mechanical parts Not reliable Not reliable Not really a computer Not really a computer –It could not make decisions

The History of Computers

Section First generation computers Section First generation computers –Atanasoff-Berry computer (ABC) 1942 at Iowa State Univversity 1942 at Iowa State Univversity Used binary number system ( 1’s and 0’s) Used binary number system ( 1’s and 0’s) Used vacuum tubes Used vacuum tubes

The History of Computers

Section First generation computers Section First generation computers –Electronic Numerical Integration and Calculator (ENIAC) 1943 (completed in 1946) 1943 (completed in 1946) Secret military project to calculate the trajectory of artillery shells Secret military project to calculate the trajectory of artillery shells Definite improvement Definite improvement –Team of mathematicians took 3 days to solve –ENIAC took 20 seconds

The History of Computers Electronic Numerical Integration and Calculator (ENIAC) Electronic Numerical Integration and Calculator (ENIAC)

The History of Computers Electronic Numerical Integration and Calculator (ENIAC) Electronic Numerical Integration and Calculator (ENIAC)

The History of Computers Electronic Numerical Integration and Calculator (ENIAC) Electronic Numerical Integration and Calculator (ENIAC)

The History of Computers Section The stored program computer Section The stored program computer –1940’s Alan Turing and John von Neumann Alan Turing and John von Neumann Stored program concept Stored program concept –Store information in a central processing unit (CPU Enter programs on paper tape Enter programs on paper tape –Instructions in machine language

The History of Computers

Section Second generation computers Section Second generation computers –1947, the invention of the transistor to replace vacuum tubes Smaller, less expensive, cooler and faster Smaller, less expensive, cooler and faster –Punched cards are replaced with magnetic tape and high speed reel-to- reel tape machines Ability to read (access) and write (store) data quickly and reliably Ability to read (access) and write (store) data quickly and reliably

The History of Computers High speed reel-to-reel tape machine

Who am I? Steve Wozniak Steve Jobs

Who am I? Bill Gates Net worth : (2008) ~ $58B SAT: 1590 out of 1600 Enrolled at Harvard University – 1973 but did not graduate

What is this? Apple 2e computer

What is this? First IBM personal computer

What is this? Apple Lisa personal computer

What is this? 1 st laptop computer Radio shack TRS-100 Hard drive : 32Kb Memory : 8Kb

The History of Computers Section High level programming language Section High level programming language –Ada Byron is credited with being the first programmer. –Advantage of programming language Instructions could be changed without flipping switches or pulling wires Instructions could be changed without flipping switches or pulling wires –High level programming language English like set of instuctions English like set of instuctions Easier to understand Easier to understand FORTRAN developed FORTRAN developed –Scientific community COBOL developed COBOL developed –Business community BASIC developed BASIC developed

The History of Computers Section Third generation computers Section Third generation computers –1961 Replace transistors with integrated circuits (IC) Replace transistors with integrated circuits (IC) –1 IC replaced 100 transistors IC are silicon wafers IC are silicon wafers

The History of Computers Section Mainframes Section Mainframes –Large computer system Multi-user applications Multi-user applications Used by large corporations, banks, government agencies and universitites Used by large corporations, banks, government agencies and universitites Terminals connect to a mainframe Terminals connect to a mainframe

The History of Computers Section Fourth generation computers Section Fourth generation computers – Intel Corporation invented the microprocessor Entire CPU on a single chip Entire CPU on a single chip – Stephen Wozniak and Steve Jobs Apple computer - first personal microcomputer Apple computer - first personal microcomputer

The History of Computers Section The personal computer Section The personal computer –Rival older mainframes in computing power –Personal computer is also know as a microcomputer Development of microprocessor led to the microcomputer Development of microprocessor led to the microcomputer –Four types of hardware components Input devices Input devices Memory Memory CPU CPU Output devices Output devices

The History of Computers Section The personal computer Section The personal computer

The History of Computers Section The personal computer Section The personal computer –Data flow between the separate components of a computer

The History of Computers Section The personal computer Section The personal computer –CPU is the ‘brain’ of the PC except….. ‘Can’t think’ ‘Can’t think’ –Software Program Program –List of instructions –Written in special language Instructions stored as electronic data that tells the hardware what to do Instructions stored as electronic data that tells the hardware what to do Operating system software - automatically starts when computer starts Operating system software - automatically starts when computer starts Applications software - written by programmers to perform specific actions Applications software - written by programmers to perform specific actions –Visual BASIC

The History of Computers Section Memory: ROM and RAM Section Memory: ROM and RAM –ROM - read only memory Permanent Permanent No effected by removing power No effected by removing power –RAM - random access memory Data stored here can be changed or erased Data stored here can be changed or erased When power is turned off, RAM is cleared When power is turned off, RAM is cleared

The History of Computers Section The CPU Section The CPU –Directs the processing of information throughout the computer –Arithmetic Logic Unit (ALU) is in CPU Arithmetic and logic calculations Arithmetic and logic calculations –Control Unit (CU) is in CPU Traffic cop of the system Traffic cop of the system Determines what happens next on the computer Determines what happens next on the computer

The History of Computers Section Number Systems Section Number Systems –Electrical circuits in chips have two states ON (1) or OFF (0) ON (1) or OFF (0) –Binary or base 2 number system is used Only uses 2 numbers Only uses 2 numbers –0 or 1 –Each 0 or 1 is called a bit –A byte is a series of 8 bits

The History of Computers Section Number Systems Section Number Systems –In order to allow computers to interchange information, the American Standard Code for Information Interchange was developed ASCII ASCII All letters and numbers All letters and numbers

The History of Computers Section Storing data in memory Section Storing data in memory –Memory size is measured in bytes 16 MB or 16 megabytes 16 MB or 16 megabytes –MB represents 2 20 or 1,048,576 bytes 256K or kilobytes 256K or kilobytes –K = kilo or 2 10 = 1024 –Bits are grouped together in units of 8 to 64 or more and are called words

The History of Computers Section Storage devices Section Storage devices –Current PC’s have 3 drives Diskette drive Diskette drive CD-ROM drive CD-ROM drive Hard drive Hard drive –All three drives use a different type of storage medium

The History of Computers Section Storage devices Section Storage devices –Other non-standard storage devices Tape drive Tape drive Removable hard drive Removable hard drive Zip drive Zip drive USB memory stick USB memory stick –Storage device of today

The History of Computers Section Object-oriented programming Section Object-oriented programming –Abbreviated as OOP –An object is a collection of data and code that performs specific tasks –Examples of OOP C++ C++ Visual Basic Visual Basic

The History of Computers Section The social and ethical implications of computers Section The social and ethical implications of computers –Right to privacy

The History of Computers Section Protecting computer software and data Section Protecting computer software and data –Piracy Illegal software copies Illegal software copies –Hacking software system Unauthorized access to software systems Unauthorized access to software systems Hacker / cracker Hacker / cracker –Virus Series of instructions buried in a program that cause the computer to destroy data or do some other harmful activity Series of instructions buried in a program that cause the computer to destroy data or do some other harmful activity

The History of Computers Section The ethical responsibilities of the programmer Section The ethical responsibilities of the programmer –Guarantee a program will work ?!?!? –Replace human judgement with fast acting computers?!?!

The History of Computers Section Why learn to program? Section Why learn to program? –Can learn what a computer can and can not do –Develop an appreciation for the important and difficult task of software creation –Development of problem solving skills –It can be fun….once the program works Develop a sense of accomplishment Develop a sense of accomplishment

The History of Computers

Group assignments Group assignments –4 groups –Chapter review questions On the web page On the web page –Written and oral presentation requirements –Lab time Typed solution (1 per group) due today Typed solution (1 per group) due today –Presentation period – next class period after the preparation lab period The History of Computers

Group assignments Group assignments –Questions on the web page –Group 1 Questions Questions –Group 2 Questions 11 – 20 Questions 11 – 20 –Group 3 Questions Questions –Group 4 Questions Questions Typed answers to your section of questions Typed answers to your section of questions –Turn in 1 solution for the group My work folder on your computer My work folder on your computer –Keep a copy to take notes on The History of Computers Group Assignments