Computer Boot Camp: How Do Computers Work?

1. Computer Boot Camp: How Do Computers Work? Donald Nelson, M.D.Gordon Baustian, M.D.Ron Reider, M.D.

2. Introduction • Computer functional parts • Computer Software / Operating systems • File systems - files and directories • Using Windows Explorer

3. The Computer’s Parts • Central Processing Unit (CPU) • Memory • Input/Output (I/O) Devices • Secondary Storage

4. Central Processing Unit (CPU) • The “brain” of the computer • Can manipulate and change information in memory • Usually a single “chip” (integrated circuit) • “Pentium II” “AMD K7”

5. The Central Processing Unit (CPU) • Control Unit / Sequencer • Fetches and interprets instructions from the memory • Directs the execution of program instructions • Arithmetic/Logic Unit (ALU) • Modifies data in response to program instructions • Add, subtract, multiply, compare, etc.

6. Computer Memory • Stores the information that the computer manipulates • Stores the programs that manipulate the information • Computer can manipulate both DATA and PROGRAMS • von Neümann architecture

7. Computer Memory • RAM - Random access memory • Read-Write • ROM - Read only memory • Stored information doesn’t change

8. Memory: Organization • All data in the computer are stored as binary numbers (composed of 1’s and 0’s) • Memory is array of storage locations • Each location designated by a number (address) • Each location contains a number (data/content)

9. Memory: Organization

10. CPU <> Memory Interaction

11. Memory: Described by • the number of locations (addresses) available • the number of binary digits (bits) stored at each location • Usually 8digits (8 bits = 1 byte) at each address

12. Memory Size • 1 Kilo = 1024 (210) locations  1000 • 1 Mega = 1,048,576 (220) locations  1,000,000 • 1 Giga = 1,073,741,824 (230) locations  1,000,000,000 • 64MB = 67,108,864 bytes = 536,870,912 bits

13. The Computer’s Parts • Input / Output Devices (I/O devices) • Allow interaction with us (users) • Allow interaction with other systems • Convert between external representation (character, image) and the internal representation (binary numbers) used in the computer

14. I/O Devices: examples • Display screen (CRT or LCD) • Keyboard • Pointing device (mouse / touch pad)

15. I/O Devices: examples • Printer • Scanner • Microphone, speakers • Modem • Network interface card (NIC) • Infrared port

16. The Computer’s Parts

17. The Computer’s Parts • Secondary Storage • Hard disk drives • Floppy disk drives • CD / writable CD • Tape drives • Etc.

18. Fast Random access Volatile Expensive Limited storage capacity Slower Indirect access Non-volatile “Cheap” High storage capacity Primary vs Secondary Storage

19. Primary vs Secondary Storage • Data the computer manipulates must be in primary memory at the time • Data in primary memory go away when power is off

20. Primary vs Secondary Storage • Stores more data than primary memory can hold • Stores programs and data between uses without consuming power • Serves as backup (can keep extra copies of important info)

21. The Computer’s Parts

22. Secondary (disk) storage • Disks store blocks of bytes much larger than individual memory locations

23. Secondary (disk) storage

24. (Whew!) • Time to change focus • Most of the time, you won’t have to pay attention to any of this while you use your computer • The computer’s software hides the gory details from the user • The Operating System

25. System Software • System Software is necessary to make the computer work. • Operating Systems • Utilities • Application Software programs accomplish the user’s tasks • Word Processors • Spread Sheets Medical Records

26. Operating System provides • a way to boot (start) the computer • control of the computer hardware: keyboard, display, mouse, printer • a file system, a way to name and organize files for storage on disk, hence Disk Operating System (DOS)

27. Operating System provides • a way to load and run user (application) programs • a way for application programs to use the hardware devices and file system

28. Operating System provides • a “User Environment” • a consistent way for application programs to interact with the user • Much of the UI is provided by Windows, not by individual programs • Windows 95 / 98 have a Graphical User Interface (GUI Interface)

29. The Graphical User Interface • GUI: “gooey interface” • The “WIMP” Interface • Windows • Icons • Menus • Pointing device (mouse, etc.) • “Point and Click”

30. Chewy (CHUI) or Gooey (GUI)?

31. Operating System may provide • multiple users - several people may use the computer at one time • security - to prevent individual programs and users from interfering with each other • Examples: UNIX Linux Windows NT with MetaFrame

32. The File System • A key function of the Operating System is to manage storage on the disk • A file system lets programs and users manage items on the disk as named files rather than physical locations • The O/S keeps track of the physical location of the files for us

33. The File System • A DIRECTORY kept by the operating system • Keeps track of each file’s name • Contains information about the file’s physical location • May keep additional information such as date created, etc.

34. The File System • Special files (subdirectories) are themselves directories • Directories may contain subdirectories, nesting to multiple levels

35. Hierarchical directories

36. Hierarchical directories

37. Windows file naming • Four part names • Drive (or device) • Path • File name • File type (extended name) • C:\Windows\System\WinTrust.hlp

38. C:\Windows\System\WinTrust.hlp • C: = Drive (hard disk named C:) • \Windows\System\ = Path • begin in “\” (root) • go to “Windows” subdirectory • go to “System” subdirectory of Windows • WinTrust = File Name • hlp = File Type (help file)

39. \\FPC-WTS01\Install\Meditech\Install.exe • \\FPC-WTS01 = Device (network host named FPC-WTS01) • \Install\Meditech\ = Path (subdirectories) • Install = file name • exe = file type (executable program file)

40. Windows file naming • Depending on the context, some or all four parts of the file name may be optional • Directories are also known as folders • Windows explorer allows visual browsing through the file system • Find function allows you to locate files without knowing the directory

41. Identify the kind of file For data files, identify the application that usually opens the file EXE - program (executable file) COM - command DOC - MS Word document PPT - PowerPoint presentation XLS - Excel spreadsheet HLP - Help file Windows file types

42. Shortcuts • Have LNK file type • Create a “dummy” file in one directory that refers to an actual file elsewhere • Effectively, the same file can exist at multiple locations in different directories • Allow you to organize your files independent of their actual locations

43. Drill and Practice • Open Windows Explorer • Use it to find “WinTrust.hlp” by browsing • Use the Find|Files or Folders function to locate the same file • Click it to see what happens

44. Drill and Practice • Explore your C: or D: drive • Create a subdirectory named “Shared” in the root directory • Create a shortcut to the “Shared” folder and place it on your desktop

45. Setting up your own directories Drive C: or D:

46. Setting up your own directories

47. Setting up your own directories

48. Setting up your own directories

49. THE END Try it for yourself.