1. CSCI-235 Micro-Computer in Science Introduction

2. Course Overview  Class webpage http://cs.stfx.ca/~ltyang/csci-235/ http://cs.stfx.ca/~ltyang/csci-235

3. © Prentice-Hall, Inc What Is a Computer?  A machine that can be programmed to accept data, process it into useful information, and store it away Data Data raw facts representing people and eventsraw facts representing people and events Information Information data that is organized, meaningful, and usefuldata that is organized, meaningful, and useful

4. © Prentice-Hall, Inc The Processing Cycle of a Computer

5. A Brief History of the Computer  First “computer”? The first actual calculating mechanism known to us is the abacus, which was invented about 2000 years ago The first actual calculating mechanism known to us is the abacus, which was invented about 2000 years agoabacus Abacus: The art of calculating with beads Abacus: The art of calculating with beadsAbacus: The art of calculating with beadsAbacus: The art of calculating with beads Adapted From: http://www.maxmon.com/history.htm

6. A Brief History of the Computer  Many references cite the French mathematician, physicist, and theologian Blaise Pascal as being the inventor of the first mechanical calculator in 1642, the Arithmetic Machine Blaise Pascal Arithmetic MachineBlaise Pascal Arithmetic Machine Adapted From: http://www.maxmon.com/history.htm

7. A Brief History of the Computer  However, it now appears that the first mechanical calculator may have been conceived by someone else almost 150 years earlier than Pascal's machine. Can you guess who? Leonardo Da Vinci Adapted From: http://www.maxmon.com/history.htm

8. A Brief History of the Computer  In the early 1800s, a French silk weaver called Joseph-Marie Jacquard invented a way of automatically controlling the warp and weft threads on a silk loom by recording patterns of holes in a string of cards Adapted From: http://www.maxmon.com/history.htm

9. A Brief History of the Computer  The first device that might be considered to be a computer in the modern sense of the word was the Difference Engine to automatically calculate mathematical tables conceived in 1822 by the British mathematician and inventor Charles Babbage Difference Engine Difference Engine Adapted From: http://www.maxmon.com/history.htm

10. A Brief History of the Computer  The Difference Engine was only partially completed when Babbage conceived the idea of another, more sophisticated machine called the Analytical Engine Analytical EngineAnalytical Engine  The Analytical Engine was intended to use loops of Jacquard's punched cards to control an automatic calculator, which could make decisions based on the results of previous computations Analytical Engine Analytical Engine Adapted From: http://www.maxmon.com/history.htm

11. A Brief History of the Computer  Working with Babbage was Augusta Ada Lovelace, the daughter of the English poet Lord Byron. Ada, who was a splendid mathematician and one of the few people who fully understood Babbage's vision, created a program for the Analytical Engine  Ada is now credited as being the first computer programmer and, in 1979, a modern programming language was named ADA in her honor Adapted From: http://www.maxmon.com/history.htm

12. © Prentice-Hall, Inc A Brief History of the Computer   In 1939, a German engineer, Konrad Zuse built the first programmable, general- purpose digital computer. His computer was built from electric relays to automate engineering calculations   “I was too lazy to calculate and so I invented the computer.”

13. © Prentice-Hall, Inc A Brief History of the Computer   John Atanasoff invented the Atanasoff-Berry Computer (ABC) —the first electronic digital computer. Built in 1939, this computer used vacuum tubes and was based on binary arithmetic. It was never a fully operational product.

14. © Prentice-Hall, Inc A Brief History of the Computer  In 1944, Howard Aiken completed the Mark I, the largest electromechanical calculator ever built. It was built with electromechanical relays and followed instructions punched in paper tape

15. © Prentice-Hall, Inc A Brief History of the Computer  The first computer “bug”

16. © Prentice-Hall, Inc A Brief History of the Computer   In 1945, Mauchly and Eckert built the ENIAC (Electronic Numerical Integrator and Computer). The ENIAC was built with 18,000 vacuum tubes that failed on an average of once every seven minutes   After the war, they created the UNIVAC I - the first general- purpose commercial computer

17. © Prentice-Hall, Inc First-Generation Computers  1930s – 1940s  Vacuum tubes used as switches  Large computers  Extremely slow by today’s standards  Prone to frequent failure  Includes the ABC, Mark I, ENIAC, UNIVAC, and others of similar design

18. © Prentice-Hall, Inc Second-Generation Computers  1950s – mid-1960s  Transistors used as switches  Smaller than vacuum-tube-built computers  As much as a thousand times faster than first-generation computers  More reliable and less expensive

19. © Prentice-Hall, Inc Third-Generation Computers  Late 1960s  Hundreds of transistors packed into a single integrated circuit on a silicon chip  Dramatic reduction in size and cost  Significant increases in reliability, speed, and efficiency  Mass production techniques to manufacture chips inexpensively

20. © Prentice-Hall, Inc Fourth-Generation Computers  1970s to present  Complete computer on a chip  Radical change in the appearance, capability and availability of computers

21. © Prentice-Hall, Inc Computer System Components  Hardware Equipment associated with the system Equipment associated with the system  Software Instructions that tell the hardware what to do Instructions that tell the hardware what to do  People Computer programmer: writes software Computer programmer: writes software User: purchases and uses software User: purchases and uses software Often called end-userOften called end-user

22. © Prentice-Hall, Inc Hardware: The Basic Components of a Computer  Four primary components: Input Devices Input Devices Processor Processor Output devices Output devices Storage Storage

23. © Prentice-Hall, Inc Input Devices: Keyboard  Most common input device Generates electrical signals which are translated into characters Generates electrical signals which are translated into characters

24. © Prentice-Hall, Inc Input Devices: Mouse  Moves over a flat surface Movement of mouse ball causes corresponding movement of pointer on screen Movement of mouse ball causes corresponding movement of pointer on screen

25. © Prentice-Hall, Inc The Processor  Also called central processing unit (CPU)  Center of activity in the computer Consists of electronic circuits Consists of electronic circuits Interprets and executes program instructionsInterprets and executes program instructions Communicates with input, output, and storage devicesCommunicates with input, output, and storage devices  Actually transforms data into information

26. © Prentice-Hall, Inc Storage: Primary Storage  Used to temporarily hold data After it is retrieved from input device and before it is processed After it is retrieved from input device and before it is processed After it is processed and before it is released to output device After it is processed and before it is released to output device  Temporary (volatile) storage Data in memory lost if power is lost or program closed Data in memory lost if power is lost or program closed

27. © Prentice-Hall, Inc Storage: Secondary Storage  Provides long-term storage Separate from memory Separate from memory  Common media Magnetic disks Magnetic disks Optical disks Optical disks Magnetic tape Magnetic tape

28. © Prentice-Hall, Inc Magnetic Disks  The most common storage media Diskette: 3.5” flexible diskette in plastic case Diskette: 3.5” flexible diskette in plastic case Hard Disk: more storage capacity and faster access than diskette Hard Disk: more storage capacity and faster access than diskette

29. © Prentice-Hall, Inc Optical Disks  Use a laser beam to read large volumes of data inexpensively CD-ROMs CD-ROMs DVD-ROMs DVD-ROMs

30. © Prentice-Hall, Inc Magnetic Tape  Stores large amounts of data inexpensively  Often used for system backup

31. © Prentice-Hall, Inc Software  All the programs that give the computer its instructions  Two categories of software: System software Application software System software Application software