operating systems programs for performing surgery not! –sorry i got carried away
TRANSCRIPT
Operating Systems
• Program that starts when you turn on your computer
• Controls devices (printers, disk drives, displays, networks)
• manages information in files and folders
• runs other programs
Example Operating Systems
• Microsoft Windows– Windows 98– Windows 2000– Windows XP
• UNIX– Linux (Open Source)– HPUX (Hewlett-Packard)– AIX (IBM)– Solaris (Sun)
• MacOS (Apple)
How are they different?
• The user interface
• The things that a user must do to work with files, folders and programs
Managing Information
• Find files
• Look at the contents of files
• Organize your files and folders
• Create and delete files and folders
• Printers and disks
What is a File?
• An array of bytes
• What do those bytes mean?– Depends on the type of file
• Word, Excel, Gif, HTML, Jpg, VRML, Java
Finding files
• By Address - – every file has a particular address on a
particular disk drive– We don’t want to know
• By Name– Pathname in a tree of folders (directories) and
files
• By Search
Viewing a File
• To look at a file we must run another program
• Run the program on double-click
• Which program will the OS run?– Depends upon the type of the file– How do we know the type of the file?
Showing File Extensions
• An extension is at the end of the file name
• Each extension has a program associated with it– .ppt => PowerPoint– .doc => Word
Showing File Extensions
• Each extension has a program associated with it– .html => Netscape– .gif => Photoshop– .txt => Notepad
File Extensions - just a record
• Many extensions can map to the same program
doc Microsoft Wordxls Microsoft Excelppt Microsoft PowerPoint
html Netscapejava Textpadtxt Notepadgif Photoshop
jpg Photoshoprtf Microsoft Word
max 3DS maxavi Media Player
mpg Media Playerwav Media Player
OS Running a program
• Reads the bytes from the file
• Places the bytes into memory
• Tells the computer to start running the instructions in those bytes