1. B.A. (Mahayana Studies) 000-209 Introduction to Computer Science November 2005 - March 2006 1. What is a Computer? An overview of what a computer is, the different types, and how we communicate with them.

2. 000-209 Intro. to CS. 1/computer? 2 Overview What is a Computer?  look at the basic elements that make up a computer Types of Computer  micros, minis, mainframes, supercomputers The User Interface  how do we communicate with the computer?

3. 000-209 Intro. to CS. 1/computer? 3 1. What is a Computer? Before 1940, a computer was a person who did calculations. The modern definition of the term computer emerged in the 1940’s.  due to World War II military needs

4. 000-209 Intro. to CS. 1/computer? 4 1.1. Von Neumann’s Definition Von Neumann, leading mathematician, wrote a report describing plans for the first computer, the EDVAC. A computer is a device that:  accepts input  processes data  stores data  produces output

5. 000-209 Intro. to CS. 1/computer? 5 1.2. Computer Diagram (v.1) Central Processing Unit (CPU) Data Storage Input Device Output Device

6. 000-209 Intro. to CS. 1/computer? 6 n Input means to send information (data) into a computer.  words from a document  numbers for a calculation  pictures, sounds, video,... 1.3. Input

7. 000-209 Intro. to CS. 1/computer? 7 Processing is the way that a computer manipulates data.  performing calculations  sorting lists and numbers  drawing graphs  making movies,... 1.4. Processing

8. 000-209 Intro. to CS. 1/computer? 8 1.5. Storage A computer stores data so that it will always be available for processing. Storage is the area where data can be left on a permanent basis. Memory is an area of a computer that holds data that is waiting to be processed.  e.g. RAM

9. 000-209 Intro. to CS. 1/computer? 9 1.5. Output Computer output is the results produced by the computer.  reports, documents, music, graphs, pictures An output device displays, prints or transmits the processing results.

10. 000-209 Intro. to CS. 1/computer? 10 1.6. Computer Diagram (v.2)

11. 000-209 Intro. to CS. 1/computer? 11 1.7. Peripherals Hardware refers to the physical things that go together to make a computer. Peripheral devices are hardware components that handle the computer’s input, output, and storage capabilities.

12. 000-209 Intro. to CS. 1/computer? 12 1.8. Software A computer needs software to tell it how to interact with the user, and how to process the user’s data. There are many types of software  see part 2

13. 000-209 Intro. to CS. 1/computer? 13 2. Types of Computer Computers can be separated into four groups, from least to most powerful:  microcomputers  minicomputers (rapidly disappearing) also known as minis  mainframes  supercomputers

14. 000-209 Intro. to CS. 1/computer? 14 2.1. Microcomputers Also known as personal computers, PCs, and micros. Typically found in homes and small businesses. Cost about US $800-4000. Speed can exceed 1,500 million operations per second. May be stand-alone, or may be connected to other computers, in order to share data and software.

15. 000-209 Intro. to CS. 1/computer? 15 A laptop computer is light, and runs on batteries or electricity A personal digital assistant (PDA) accepts info on a touch-sensitive screen Desktop microcomputer Microcomputers

16. 000-209 Intro. to CS. 1/computer? 16 Two major types:  PCs originally created by IBM now also Compaq, Dell, HP, Acer,...  Macintoshs (Macs) made by Apple Computers Desktop Microcomputers The iMac

17. 000-209 Intro. to CS. 1/computer? 17 2.2. Mainframes Large, fast, and fairly expensive computers. Used by business and government. Storage, processing, and management of large amounts of data. Can support thousands of users. Often uses several central processing units (CPUs).

18. 000-209 Intro. to CS. 1/computer? 18 2.3. Supercomputers Fastest and most expensive type of computer. Cost between US $500,000 and $35 million. Now used in business markets to handle large amounts of data. Processes more than 1 trillion instructions per second. Applications:  weather forcasting, military simulations, cartoons like Shrek

19. 000-209 Intro. to CS. 1/computer? 19 3. The User Interface The means by which humans and computers communicate. A good user interface is easy to learn and use. User interfaces are still improving.

20. 000-209 Intro. to CS. 1/computer? 20 3.1. GUIs Graphical objects are a key element of the Graphical User Interfaces, or GUIs, found on most of today’s microcomputers.

21. 000-209 Intro. to CS. 1/computer? 21 3.2. Microsoft Windows GUI

22. 000-209 Intro. to CS. 1/computer? 22 Mac OS X GUI

23. 000-209 Intro. to CS. 1/computer? 23 n A command is an instruction you input to tell the computer to carry out a task. n Command words are often English words, such as print, begin, save, and erase, but they can also be harder to remember. 3.3. Computer Commands

24. 000-209 Intro. to CS. 1/computer? 24 A menu displays a list of commands or options. 3.4. GUI Elements continued

25. 000-209 Intro. to CS. 1/computer? 25 Submenus are additional sets of commands that the computer displays after you make a selection from the main menu. continued

26. 000-209 Intro. to CS. 1/computer? 26 Dialog boxes display the options associated with a command. continued

27. 000-209 Intro. to CS. 1/computer? 27 n Graphical objects are small pictures on the screen that you can manipulate using a mouse or other input device. n Graphical objects include icons, buttons, and windows. Icons Selected icon