Windows and Operating Systems by pengxuebo


									Computer Boot Camp:
How Do Computers Work?

 Donald Nelson, M.D.
 Gordon Baustian, M.D.
 Ron Reider, M.D.

 Computer functional parts
 Computer Software / Operating systems
 File systems - files and directories
 Using Windows Explorer
The Computer’s Parts
 Central Processing Unit (CPU)
 Memory
 Input/Output (I/O) Devices
 Secondary Storage
Central Processing Unit (CPU)
 The “brain” of the computer
 Can manipulate and change information in
 Usually a single “chip” (integrated circuit)
 “Pentium II” “AMD K7”
The Central Processing Unit
 Control Unit / Sequencer
  • Fetches and interprets instructions from the
  • Directs the execution of program instructions
 Arithmetic/Logic Unit (ALU)
  • Modifies data in response to program
  • Add, subtract, multiply, compare, etc.
Computer Memory
 Stores the information that the computer
 Stores the programs that manipulate the
 Computer can manipulate both DATA and
  • von Neümann architecture
Computer Memory
 RAM - Random access memory
  • Read-Write
 ROM - Read only memory
  • Stored information doesn’t change
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
 Each location contains a number
Memory: Organization
CPU <> Memory Interaction
Memory: Described by
 the number of locations (addresses)
 the number of binary digits (bits) stored at
  each location
 Usually 8digits (8 bits = 1 byte) at each
Memory Size
 1 Kilo = 1024 (210) locations  1000
 1 Mega = 1,048,576 (220) locations 
 1 Giga = 1,073,741,824 (230) locations 
 64MB = 67,108,864 bytes = 536,870,912 bits
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
I/O Devices: examples
 Display screen   (CRT or LCD)
 Keyboard
 Pointing device (mouse / touch pad)
I/O Devices: examples
 Printer
 Scanner
 Microphone, speakers
 Modem
 Network interface card (NIC)
 Infrared port
The Computer’s Parts
The Computer’s Parts
 Secondary Storage
  •   Hard disk drives
  •   Floppy disk drives
  •   CD / writable CD
  •   Tape drives
  •   Etc.
Primary vs Secondary Storage
 Fast               Slower
 Random access      Indirect access
 Volatile           Non-volatile
 Expensive          “Cheap”
 Limited storage    High storage capacity
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
Primary vs Secondary Storage

 Stores more data than primary memory can
 Stores programs and data between uses
  without consuming power
 Serves as backup (can keep extra copies of
  important info)
The Computer’s Parts
Secondary (disk) storage
   Disks store
    blocks of bytes
    much larger than
Secondary (disk) storage
 Time to change focus
 Most of the time, you won’t have to pay
  attention to any of this while you use your
 The computer’s software hides the gory
  details from the user
 The Operating System
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
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)
Operating System provides

 a way to load and run user (application)
 a way for application programs to use the
  hardware devices and file system
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)
The Graphical User Interface
 GUI: “gooey interface”
 The “WIMP” Interface
  •   Windows
  •   Icons
  •   Menus
  •   Pointing device (mouse, etc.)
 “Point and Click”
Chewy (CHUI) or Gooey (GUI)?
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
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
The File System
 A DIRECTORY kept by the operating system
  • Keeps track of each file’s name
  • Contains information about the file’s physical
  • May keep additional information such as date
    created, etc.
The File System
 Special files (subdirectories) are
  themselves directories
 Directories may contain subdirectories,
  nesting to multiple levels
Hierarchical directories

         Drive C:

         \ [root]

         My Documents

         Program Files

Hierarchical directories
          Drive C:

          \ [root]

          My Documents

          Program Files



              Start Menu

Windows file naming
 Four part names
  •   Drive (or device)
  •   Path
  •   File name
  •   File type (extended name)
 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)

 \\FPC-WTS01     = Device (network host
  named FPC-WTS01)
 \Install\Meditech\ = Path (subdirectories)
 Install = file name
 exe = file type (executable program file)
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
Windows file types
 Identify the kind    EXE - program (executable
  of file               file)
 For data files,      COM - command
  identify the         DOC - MS Word document
  application that     PPT - PowerPoint
  usually opens         presentation
  the file
                       XLS - Excel spreadsheet
                       HLP - Help file
 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
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
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
Setting up your own directories

                    \ [root]

                    My Documents
 Drive C: or D:





Setting up your own directories
Setting up your own directories
Setting up your own directories

      Try it for yourself.

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