1. Computer and Information Science Computer Software and Networking Computer Software and Networking Chapter 1.2

2. AgendaAgenda n Application Software n Operating Systems

3. SoftwareSoftware n Software is the programs and data that a computer uses. n Programs are lists of instructions for the processor. n Data can be any information that a program needs: character data, numerical data, image data, audio data, and countless other types. –Digitizing : –Digitizing :The process of taking a visual image, or audio recording and converting it to a binary form for the computer.

4. Types of Programs n Imagine that you have just turned on your computer and have not yet started any application. Are any programs running? n Two types of software –Application software –System software/Operating systems

5. Why do we need an OS? n n What are the goals of an Operating System? –The primary goal of an Operating System is to make the computer system convenient to use. –The secondary goal is to make the computer system efficient to use.

6. An Operating System n n It underlies all other software. n acts as an interface between a user of a computer and the computer hardware n It acts as an interface between a user of a computer and the computer hardware n It manages and coordinates computer system resources ( CPU, memory, file system, I/O devices) n n It provides the user Interface that is: –How can something as simple-minded as a processor and memory present you with something as rich as the Mac or Windows GUI?

7. Operating system services... Control basic input and output Allocate system resources Manage storage space

8. Operating Systems Detect equipment failure Maintain security Operating system services...

9. You ask MS Word to OPEN a document –File menu/Open… –WHAT WILL YOU SEE? –What really just happened in the box? WORD called on O.S. to present you with that file list! O.S. must look at: 1.Disk Directory (list of filenames) 2.File Allocation Table (FAT)…. (list of file locations: starting position/cluster number on the disk) System calls

10. Multi-tasking n n >1 program or person can share computer resources. –CPU is idle ~90% of time, waiting for user input ! –One program active; Others running in the background OS must protect each program ’ s memory area to ensure that instructions and data don ’ t “ leak ” into an area allocated to another program. If it fails, programs can crash … more shortly!

11. Booting and BIOS n When a computer is started up, the hardware will automatically load the operating system and start it running. This process is called booting. n BIOS is the boot program on a computer, and controls the computer from the time you start it up until the operating system takes over. When you turn on a PC, the BIOS first conducts a basic hardware check, called a Power-On Self Test (POST), to determine whether all of input/output devices are present and working. Then it loads the operating system into your computer's RAM.

12. ROM (Read-only-Memory) n ROM refers to computer memory chips containing permanent or semi-permanent data. Unlike RAM, ROM is non-volatile; even after you turn off your computer, the contents of ROM will remain. n BIOS is stored in a ROM.

13. Various Operating Systems n n Windows : Developed by Microsoft XP, Vista, windows7 n n Unix: Developed by AT&T for large companies n n Linux: Open Source version of Unix n n Mac OS: only for Mac hardware e.g. Snow Leopard

14. UNIX SunOS UNIX login: smith Password: Last login: Oct 15 17:42:09 from tserv1.edu SunOS Release 4.1.1 #1: Wed Mar 20 11:24:14 AST 1991 You have mail. % _ UNIX features a command line interface. Designed for minicomputers but is now also available for micros and mainframes. The UNIX prompt Microcomputer Operating Systems Why is it important for me to know which operating system is on my computer?

15. IMPORTANT ! WHAT HAPPENS when you SHUT DOWN improperly? Why should you care? “Shutting down incorrectly is a little like stopping your car by driving it into a wall. It works, but it can cause some damage.”

16. Computer terms bingo n Follow the link http://www.wcu.edu/ceap/Kirk/Merlot _Resources/KnowYourComputerTe rms.swf http://www.wcu.edu/ceap/Kirk/Merlot _Resources/KnowYourComputerTe rms.swf

17. NetworksNetworks n Computer Network: series of computers linked together to share data, hardware, and software n Local Area Network (LAN) : series of computers networked together over a relatively limited area –campus –building

18. Stand-alone computer — a computer not connected to a network. Workstation — name for a computer when it is connected to a network. Local resources — workstation ’ s typical resources: hard drive, software, data, and printer. Network resources — additional resources you have access to when connected to a network: application software, storage space for data files, and shared printers. Key Network Terms

19. Network server — a computer connected to the network that distributes resources to network users. Network printer — a shared printer that provides output capabilities to all network users. Node — a device on a network, including workstations, servers, and printers.

20. n Identifies you as a user on the network n Logically connects a workstation to network drives and other resources n Requires a user to enter a user ID and password The login process...

21. User account — provides access to network resources. Network administrator or supervisor — person responsible for setting up user accounts and maintaining the network.

22. Mapping — assigning drive letters to network server disk drives. What drives are available??

23. View a directory or access files on network server drive F just as you would drives A and C. Your workstation floppy drive A Network server drive F Your workstation hard disk drive C Network printer

24. Using Programs on the Network Step #1

25. Step #2

26. Step #3

27. n Disk storage space n Time and effort in updating software n Licensing costs Sharing a program — with proper licensing many network users can access a program at the same time and save...

28. Parallel port Workstation Network printer Using a Network Printer  The login process usually assigns a network printer to your workstation.  Output is redirected (captured) from the parallel port to the network printer.

29. Two documents are sent to a network printer at the same time... Print Queue: 1. Ceo.Doc 2. Gnp.Doc Ceo.doc arrives first Gnp.doc arrives before printer completes Ceo.doc Print queue — special holding area on the network server where files are stored until they are printed.

30. Network interface card (NIC) — small circuit board that plugs into expansion slot. – Key component for connecting your computer to a local area network – Sends data from a workstation over the network – Collects incoming data intended for your workstation Network Hardware

31. Desktop network interface card (NIC)

32. Connecting Networks n Similar to telephone cable n Has a plastic RJ- 45 connector on either end Twisted pair cable (UTP) —

33. Wireless networks use radio or infrared signals to transmit data from one network device to another. The network interface card contains the transmitting devices. Other Network Connectors

34. n Provide mobility n Are used in environments where wiring is hard to install n Can be good for temporary installations Wireless networks:

35. Software for Networks A network requires some special network software in addition to much of the same application software typical of standalone computers.

36. Network license: n Permits specified number of people to use software on a network n Costs more than one single-user license but less than individual licenses for all network users n Available for most software packages by contacting the publisher

37. E-mailE-mail Electronic mail (e-mail) is correspondence conducted between users on a computer network. Electronic mail (e-mail) is correspondence conducted between users on a computer network.

38. n E-mail messages are stored on a server n When you read your mail, the server forwards it to your workstation Store and forward technology:

39. Mail server Your workstation 1. E-mail addressed to you is sent to the mail server 2. Mail stays on the mail server until you log on to your mail client. 3. Server forwards your mail to your workstation when you’re ready to read it.

40. VOIPVOIP VoIP allows you to make telephone calls using the Internet. Voice communication among the computers, free of charge Calls to phone numbers for a fee

42. Streaming Media n n Streaming media technology enables you to include audio, video and other multimedia files into your web site.

43. Downloading vs Streaming n n Downloading :The user downloads the file from the web server to her local hard disk, and then plays back the content using a player. n n Streaming: The media Server sends data over the network only at the speed that is necessary for the client to render it properly and allows live content delivery.

44. More Internet Applications n. n FTP is a standard network protocol used to exchange and manipulate files over the Internet.network protocolInternet n Instant Messaging, originally a real-time communication via the Internet using typed text and now includes voice and video