Operating System & File System Prof. Sujata Rao Lesson 7

The Computer Operation System This lesson will cover: Computer Operating Systems GUI vs. Command line The Microsoft Windows Family The Concept of Windows Windows XP File Systems – How Computers Manage Data SSR/ver 1.4Operating system & File types 2

Different Systems for Different Needs Different computers, different tasks and various level of competency i.e. Mainframe & Micro PC. Different Operating Systems, different functionality and usability. – UNIX or Linux – very robust and secure, however very difficult for the average user to understand and use effectively. So usually used on network servers and engineering or programming workstations. –Windows – not so finicky. Neither very secure nor stable compared to UNIX, but very easy to master. A compromise between functionality and usability. SSR/ver 1.4Operating system & File types 3

GUI Vs. Command Line Windows XP, like Windows 98 is a Graphical User Interface, or GUI. It uses graphical representations of theGUI underlying complexities of the operating system to eliminate the need to learn complex commands. This makes using the software easier and more efficient. Most modern operating systems have GUIs, such as the MacOS, Unix and Linux. Windows was originally developed as an interface for MS-DOS. SSR/ver 1.4Operating system & File types 4

Notice the difference… Two DOS commands, “time” and “date”, were entered with primitive results… SSR/ver 1.4Operating system & File types 5

In the Windows Setup … one click on the taskbar makes this Time & Date option available. SSR/ver 1.4Operating system & File types 6

UNIX Operating System One of the first multi-user, multi-tasking operation systems Very robust and stable Provides built in networking capabilities. Known for its cryptic commands. Many version of UNIX developed by different sources such as Solaris, System V and SCO UNIX. SSR/ver 1.4Operating system & File types 7

Linux Operating System Linux is a free ‘Unix-like’ operating system. Many of the same features of UNIX Available for many operating platforms. SSR/ver 1.4Operating system & File types 8

OS/2 Is a 32-bit multitasking operating system produced by IBM. Used by many large corporations in mission critical functions such as banking, ATM etc. Co-developed by IBM and Microsoft to replace DOS (Disk Operating System) in late 1980s. SSR/ver 1.4Operating system & File types 9

Windows XP Is the latest version of Microsoft Windows family. Two distinct versions of this OS for use on desktop PCs i.e. XP Home Edition and XP professional and there are other versions for use as network servers. Is actually descendent of the Windows NT family rather than the windows 9x family. Difference between Home Edition & Professional version: –Advanced networking features for domain-based networks –Remote Access capabilities –Encrypting File System (EFS) –Support for multiple-processors –Support for multiple languages SSR/ver 1.4Operating system & File types 10

File Systems – How Computers Manage Data To understand Window’s use of files and folders, you need to know just a small bit about how a computer stores information. Computers store data which are pieces of information.data A computer’s file system is its method of organizing the data stored on its Secondary or Mass storage devices, such as hard disks and cd-roms. Generally the file system is dictated by the Operating System, each having its own type i.e. Windows XP can use more than one file system (Discussed in detail in later chapters)SecondaryMass storage Operating System SSR/ver 1.4Operating system & File types 11

File Systems – How Computer Manages Data The three basic elements of the Windows XP file system are: –File –Folder or Directory –Drive or Partition SSR/ver 1.4Operating system & File types 12

File A file is a collection of data. It is the smallest element of a file system and is a collection of bits and bytes to represent information in the form of text, image etc.file Basic types of files: –Data files - stores only data and used by executable files as a source of input or output and Executable files. –Executable files - performs operations under OS, i.e. Applications. Examples of common file types used by Windows and Windows based programs are: SSR/ver 1.4Operating system & File types 13

Program – a program file is one that can be executed or “run”. Text – this is the most basic form of text file, it is sometimes called a “plain” or “ASCII” text file.ASCII System configuration - this type of file can be of several types such as an.ini,.sys or.dat file they store information that the system (or a program) needs to have readily available to function properly. Compressed – a file of this type has been compressed by a program to reduce its size as a space saving measure.compressed TrueType font file – the standard Windows font type is stored in this kind of file. Formatted text document – a document formatted by a word processor. SSR/ver 1.4Operating system & File types 14

Folders and Drive/Partition A folder is a collection of files. Folders are used to organize the file system of a Windows based PC. The analogy of files and folders on a PC and files and folders in a file cabinet in an office is the easiest way to explain this relationship.folder A drive can be any mass storage device such as a hard drive, a cd- rom drive, zip drive, or a floppy drive. Some types of drives used by Windows are:mass storage CD-ROM or DVD drive Hard drive or a partition of a physical drivepartition Floppy disk drive Removable media drive, such as a Zip driveZip Network drive SSR/ver 1.4Operating system & File types 15

Relationship of Files to Folders to Drives: On a Windows PC files are stored in folders on a drive… A drive can actually be a part of a physical drive. This is called a drive partition. So one hard disk can have several drives labeled as letters from C to Z. The C: drive is always the first hard drive.physicalpartition SSR/ver 1.4Operating system & File types 16

A hierarchical File Tree Windows XP uses a hierarchical or TREE file system….hierarchical …such an arrangement uses directories, or folders, to organize the data files. The diagram to the left shows how this system, called a “tree”, is structured. The top level is called the root directory or simply the “root”. This directory contains all the files and folders below it. The subordinate folders may contain only files, or only folders or both. This is how the Windows Explorer presents the file system. “My Computer” in XP is such a root.treeroot SSR/ver 1.4Operating system & File types 17

XP’s “My computer” folder contains the file system tree that closely resembles the generic tree seen before. The A drive (floppy) The C drive The My Computer folder is the place where the file system tree is located… The CD-ROM drive The Desktop folder Zip drive Network drive SSR/ver 1.4Operating system & File types 18

A hierarchical File Tree – File Path Every file has a path. A file’s path is simply the complete address for that file within the file hierarchy. For example a file that exists: On the C drive In the Program Files folder, In the Windows NT sub-folder, In the Accessories sub-folder, Named wordpad.exe would have the following path: C:\Program Files\Windows NT\Accessories\wordpad.exe SSR/ver 1.4Operating system & File types 19

Files and Folders As stated before files store data in different ways. The difference can be like a text file versus program code, or an Word document and a WordPerfect document. The first two point out a difference in the actual data, the second pair a difference in “formatting”. Many times a file’s content can be known by the file extension, that is the trailing letters of the filename after the “.” For example a file named opera.exe is an executable file (which is another name for a program file). The following slide lists several file types and their respective extensions. SSR/ver 1.4Operating system & File types 20

Files and Folders File ExtensionApplication EXE, COMExecutable file ZIPCompressed file using “Zip” compression INIConfiguration files, many programs use them, too TXTASCII text file, sometimes called “plain text” DOCMicrosoft Word file XLSMicrosoft Excel file PPT, PPSMicrosoft PowerPoint file MDBMicrosoft Access database file GIF, JPG, PNGImage files HTM, HTMLHyperText Markup Language file PDFAdobe Acrobat Portable Document Format SSR/ver 1.4Operating system & File types 21

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