1. Chapter 1 Computers and Programming Languages

2. 1.1 Mechanical Devices -Pascaline (invented in 1642 by Blaise Pascal) -complicated set of gears -worked similarly to a clock -only performed addition -never worked properly -Stepped Reckoner (invented by Gottfried Wilhelm von Liebniz) -suppose to add/subtract/multiply/divide -included a cylindrical wheel -tended to jam and malfunction

3. -Difference Engine (imagined in 1822 by Charles Babbage) -was intended to print out numbers to the 40 th place -purpose was to produce navigation tables -unfortunately never built -Analytical Engine (designed around 1833 by Charles Babbage) -supposed to follow a set of instructions stored on punch cards -during processing it was planned to store information in a memory unit and make decisions based on the stored content -Although never built its design served as the template for the modern computer -Ada Byron (collaborator) considered first programmer -Ada said it could never “originate anything” meaning that it could not think

4. 1.2 Electro Mechanical Devices Tabulating Machine (invented by Herman Hollerith) -invented to compute 1890 census -used electricity instead gears to perform calculations -holes representing information were punched in cards -different locations of the holes represented different info. -cut the time to compute the census by over 2 years

5. Mark 1 (completed by team in 1944 led by Howard Aiken) -team was from International Business Machines (IBM) -used telephone relay switches to store information -accepted data from punch cards -since it could not make decisions about the data it was nothing more than a sophisticated calculator -51 feet in length, weighed more than 5 tons, and had 750,000 moving parts

6. 1.3 First Generation Computers Atanasoff-Berry Computer (ABC) – 1 st electronic computer -built between 1939-1942 -by John Atanasoff and Clifford Berry -used binary number system of 0’s and 1’s (still used) -contained hundreds of vacuum tubes -stored numbers by electronically burning holes in paper -patent application wasn’t handled properly and it took nearly 50 years for Atanasoff to receive credit

7. ENIAC (Electronic Numerical Integration and Calculator) -Built by John Mauchly & J. Presper Eckert -finished in 1946 (took 3 years) -originally a secret military project to calculate the trajectory of artillery shells -in its 1 st demonstration it solved a problem that took a team of mathematicians 3 days to solve in less than 20 seconds -was the size of an average 3 bedroom house

8. 1.4 The Stored Program Computer -Alan Turing & John von Neuman both credited with idea of stored programs -EDVAC & EDSAC were 1 st program controlled computers -programs were written in machine language and stored on paper tape -UNIVAC (3 rd computer to use programs) -Used first computer language C-10 written by Francis Holberton -These computers were very large and expensive

9. 1.5 Second Generation Computers -William Shockley, John Bardeen, Walter Brittain of Bell Laboratories invented the transistor in 1947 -Transistors were smaller, less expensive, and faster than vacuum tubes -Model 650 (released in early 1960’s by IBM) -1 st medium size computer -very popular despite high costs -Punch cards were replaced by magnetic tape giving computers the ability to read and write data quickly and reliably

10. 1.6 High Level Prog. Languages -Fortran (Developed in 1957 by John Backus and team) -introduced commands READ and WRITE -COBOL (Developed by Dept of Defense in 1959) -ADA (Developed by Dept of Defense in 1970’s) -supports real time applications -still commonly used in the banking industry -BASIC (Developed to teach students in the 1970’s) -Object Oriented Prog. (OOP) languages were designed in the 1980’s (C++, Java, and Visual Basic are most common)

11. 1.7 Third Generation Computers -Integrated Circuits (IC’s or Chips) -developed by Jack Kilby and Robert Noyce in the early 1960’s -One chip could replace hundreds of transistors and perform millions of calculations per second -They have 2 settings on/off -System 360 (released in 1964 by IBM) -1 st computers to use IC’s -Inexpensive enough that universities and hospitals could afford them -so popular that IBM couldn’t keep up with demand

12. 1.8 Mainframes -Usually large and kept in their own room -Used to store and process large amounts of data -IBM System 360 was first mainframe -Users used terminals to connect to mainframe

13. 1.9 Fourth Generation Computers -Microprocessor (invented by Marcian Hoff of Intel in 1970) -Allowed the development of the microcomputer (desktop) -Altair (1 st desktop, built in 1975 by Apple Macintosh) -Designed by Stephen Wozniak & Steven Jobs -Used first G.U.I. -IBM-PC (released in 1981 by IBM) -immediate commercial success due to spreadsheet, accounting, and word processing software -The drop in cost now made the personal computer affordable for the public

14. 1.10 The Personal Computer -Physical Components of computer are called hardware -Monitor, keyboard, mouse, CD/DVD drive, case, etc. -Input Devices (keyboard, mouse, CD/DVD drive) -Output Devices (Monitors, printers are most common) -Visual Aide (page 1) -Motherboard (main circuit board) -CPU/ALU -Memory (ROM/RAM/SRAM) -Bus/Data Bus/Address Bus/Control Bus -Visual Aide (page 2) -Software -Operating System/Application

15. 1.11 Networks -Networks are widely used by businesses, universities, etc… -Allows users to reliably share and exchange data -Can reduce costs by sharing peripheral devices -Can be set up to allow users access to only specific files -Simplifies the backup process -Allows users to communicate with email -Classified by Size, Architecture, and Topology -Size (LAN/WAN) -Architecture (Client-Server/Peer-to-Peer) -Topology (BUS/STAR/LOOP) -Visual Aide (page 3)

16. 1.12 Number Systems -3 Common Number Systems (Binary, Decimal, Hexadecimal) -Visual Aide (page 4) -Decimal (base 10) -uses numbers 0 – 9 (our common number system) -example: 30 -Binary (base 2) -uses numbers 0 & 1 (represents the on/off setting in IC’s) -organized into 8-bit units called bytes -example: 0001 1110 -Hexadecimal (base 16) -uses numbers 0 – 9 and letters A – F -example: 1E -Unicode (set of 16 0,1’s to represent every letter/symbol) -Visual Aide (page 6)

17. 1.13 Storing Data in Memory -Computer memory, file sizes, and storage device capacities are measured in bytes. Large sizes might be in (KB/MB/GB/TB) -Data stored in memory is referred to by an address -each address has a unique binary representation -storing the name JIM (see Visual Aide – page 5)

18. 1.14 Social & Ethical Implications of Computers -Netiquette -Do not attempt to access the account of another user without authorization -Do not share your password and change it periodically -Use appropriate subject matter and language, and be considerate of other people’s beliefs and opinions -Laws to protect privacy -Fair Credit Reporting Act of 1970 -Privacy Act of 1974 -Financial Privacy Act of 1978 -Electronic Communications Act of 1986 -Electronic Freedom of Information Act of 1996 -Safety and Freedom through Encryption Act of 1999

19. 1.15 Protecting Computer Software and Data -Piracy (software, music, and movies) -Precautions to avoid viruses -Install antivirus software and update frequently -Enable a firewall -Monitor downloads from unknown sources (email/internet)

20. 1.16 Ethical Responsibilities of the Programmer -Create programs that will “always” operate properly -Test, debug, and collaborate to ensure this -plan for errors for if and when they do happen -Remember computers are being used more frequently in areas where judgment is required, and computers can only follow instructions so they must be comprehensive and correct

21. Chapter 1 Review