What is a program?

1. What is a program? IT skills: none IT concepts: computer components, program, executing (running) a program, operating system, program and data, multitasking, virtualization This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License.

2. Where does this topic fit? • Internet concepts • Applications • Technology • Implications • Internet skills • Application development • Content creation • User skills

3. Applications require programs

4. Recipes are lists of instructions for chefs Combine Coca-Cola and buttermilk; set aside. Beat butter at low speed with an electric mixer until creamy. Gradually add sugar; beat until blended. Add egg and vanilla; beat at low speed until blended. Combine flour, cocoa, and soda. Add to butter mixture alternately with cola mixture; begin and end with flour mixture. Beat at low speed just until blended. Pour batter into a greased and floured 13- x 9-inch pan. Bake at 350° for 30 to 35 minutes. Remove from oven; cool 10 minutes.

5. Programs are lists of instructions for computers Display “Do you like me?” Input likeme If likeme = “yes” display “I like you too!” If likeme = “no” display “You are ugly!” Stop What will happen when this program is executed?

6. Display “Do you like me?” Input likeme If likeme = “yes” display “I like you too!” If likeme = “no” display “You are ugly!” Stop Do you like me? _

7. Display “Do you like me?” Input likeme If likeme = “yes” display “I like you too!” If likeme = “no” display “You are ugly!” Stop Do you like me? yes I like you too! stop

8. Display “Do you like me?” Input likeme If likeme = “yes” display “I like you too!” If likeme = “no” display “You are ugly!” Stop Do you like me? Yep What will happen if the user types “yep?”

9. Display “Do you like me?” Input likeme If likeme = “yes” display “I like you too!” If likeme = “no” display “You are ugly!” Stop Do you like me? yep stop

10. Let’s look inside the computer CPU Input devices Memory Output Devices Storage devices (programs and data)

11. What is in memory? Operating system (master control program) Application program Application data

12. Our example Operating system (master control program) Application data Application program Likeme: Display “Do you like me?” Input likeme If likeme = “yes” display “I like you too!” If likeme = “no” display “You are ugly!” Stop yes

13. Running Word What would be in memory?

14. Program, data and operating system How would this diagram change if we were running both Excel and Word?

15. Multitasking Operating system (master control program) Data Data Data Data Program Data Program Data Data Data

16. Virtualization Prog Doc … Prog Doc ... Prog Doc ... Operating system 1 Operating system 2 Operating system 3

17. Windows and Mac OS-X Virtualization is used primarily on servers.

18. Summary Do you like me? _

19. Self-study questions What would be displayed if the user of our simple program example had entered “no” when the computer asked “do you like me”? What would be displayed if the user entered “for sure”? What if the user answered in capital letters, “YES”? We used Microsoft Word as an example word processing program– is Word a network application? (Explain) When you type text into a word processing program, is it displayed before it is put in memory or put in memory then displayed? (Explain). We saw that a program must be in memory if it is to be executed. When using Microsoft’s Windows operating system, how do you cause a program to be loaded from storage to memory and executed? (Hint: what do you do to cause Microsoft Word to be loaded into memory from storage). We saw that data like word processing documents are copied from memory to storage when they are finished. If you create a document using Microsoft Word, how do you get the computer to store it? Is the operating system hardware or software? (Explain) Are the examples in this presentation network-based programs or stand-alone?

20. Resources A taste of programming – interactive tutorial: http://www.codecademy.com/ More programming tutorials: http://www.w3schools.com/