Transcript File - CSUS

The Computer Operating System
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
…these topics are from Chapter 2…and then some.
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.
GUI Vs. Command Line
Windows XP, like Windows 98 is a Graphical User
Interface, or GUI. It uses graphical representations of the
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.
Notice the difference…
Two commands, “time” and “date”, were entered with
primitive results…
Notice the difference…
…when one click on the taskbar gives you this.
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.
Linux Operating System
• Linux is a free ‘Unix-like’ operating system.
• Many of the same features of UNIX
• Available for many operating platforms.
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.
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:
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Advanced networking features for domain-based networks
Remote Access capabilities
Encrypting File System (EFS)
Support for multiple-processors
Support for multiple languages
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.
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)
File Systems – How Computer
Manages Data
• The three basic elements of the Windows
XP file system are:
– File
– Folder or Directory
– Drive or Partition
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.
•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:
• 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.
• 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.
• 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.
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.
•A drive can be any mass storage device such as a hard drive, a cdrom drive, zip drive, or a floppy drive. Some types of drives used by
Windows are:
• Hard drive or a partition of a physical drive
• Floppy disk drive
• CD-ROM or DVD drive
• Removable media drive, such as a Zip drive
• Network drive
Relationship of Files to
Folders to Drives:
On a Windows PC files are stored in folders on a drive…
Relationship of Files to Folders to Drives
Hard Drive
Partition
File
Folder
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.
A hierarchical File Tree
Windows XP uses a hierarchical or TREE file system….
A file system "Tree"
Root level
…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.
XP’s “My computer” folder contains the file system tree that
closely resembles the generic tree seen before.
The Desktop folder
The My Computer folder is the place
where the file system tree is located…
The A drive (floppy)
The C drive
Zip drive
The CD-ROM drive
Network drive
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
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.
Files and Folders
File Extension
Application
EXE, COM
Executable file
ZIP
Compressed file using “Zip” compression
INI
Configuration files, many programs use them, too
TXT
ASCII text file, sometimes called “plain text”
DOC
Microsoft Word file
XLS
Microsoft Excel file
PPT, PPS
Microsoft PowerPoint file
MDB
Microsoft Access database file
GIF, JPG, BMP, PNG Image files
HTM, HTML
HyperText Markup Language file
PDF
Adobe Acrobat Portable Document Format