CS609 Updated Handouts Set 2

Lesson 1

Topic 1: Windows Operating System

Software can be categorized into two main types: System Software and Application Software. System Software is concerned to the system or its resources while Application Software is related to some application. Operating System is one of the good examples of System software that acts as a manager for the System’s resources. It arbitrates and schedules the resources among the processes to avoid any kind of conflicts.

There are varieties of Operating Systems available in the market but Windows is one of the important Operating Systems developed by Microsoft. It is widely used inside the PCs, Laptops, enterprise servers, handheld devices and cell phones etc.

Core Features of Windows Operating System

1. Memory Management. Memory Management is the vital or key feature of Windows Operating System. The OS is responsible for managing primary as well as secondary memory. Virtual address space on secondary memory is also managed by OS to transfer data between primary and secondary storage and accommodate a large process in small memory space. All kinds of services and related data structures are supported by Operating Systems to efficiently manage the Virtual memory space.

2. File systems. Windows OS manages all kinds of files and folders on disk in hierarchical form. Large file naming space of 255 characters is supported by the OS. Number of APIs are provided by the OS to access the files in both Sequential and Random mode.

3. Processors. Windows Operating System provides support to multiprocessors and multi cores systems. It also arbitrates among the cores or processors to efficiently divide and allocate computational tasks to them.
4. Resource naming and location. In Windows OS, the resources like processes or devices are treated as objects and each object is assigned a unique name to identify, locate and access it.
5. Multitasking. Windows OS supports multitasking. It manages processes, threads, and other independent units, and their asynchronous execution. Tasks can be preempted and scheduled according to dynamically calculated priorities.
6. Communication and Synchronization. The Windows OS provides constructs to manage inter-process communication and synchronization within a computer or networked computers.
7. Security and Protection. The Windows OS has a strong security mechanism to protect resources from illegal and accidental access. A user cannot access other user data without assigning privileges.

Lesson 2

Topic 2: Windows Evolution

Windows exist in several versions. New versions of Windows are introduced from time to time. Actually, certain new APIs are included in the new version to improve or extend its functionalities. The following major themes or features are considered while developing a new version.

Scalability. A new version of Windows OS runs on different platforms including PCs, enterprise servers, multiprocessing systems, mobiles and systems having large memory space. Performance. A newer version of Windows certainly improves performance compared to previous versions. Integration. A newer version must integrate with new technologies like web services, .NET technologies, multimedia etc. Ease of use. Certain new APIs and improved GI in the new version can ensure ease of use. Enhanced API. Introducing new APIs or enhancements in existing APIs should be the main theme of the new version.

Disk Operating System (DOS)

In the 1980s, Microsoft Disk Operating System was used inside the IBM PCs incorporating Intel Processor. It was a text based and command line operating system. It was a single user OS. Its filing system was based on FAT and was able to access up to the maximum of 4GB files.

Windows History

Keeping the demand of graphical user interface, Microsoft developed its first version Windows

3. 1. In this version, DOS Kernel and FAT based file systems were used.

After that in the 1990s, certain new versions of Windows named Windows 95, 97 and 98 were introduced supporting the 32-bit architecture of Intel’s processors.

Later on, Windows NT versions were introduced supporting a file system based on new technology called NTFS. Its security and file system were better than the previous versions.

Windows Server 2008 OS was developed for professional use to manage enterprise and server applications. Support for multi-core technology and 64-bit applications was provided in this OS. Other Windows versions supporting 32-bit, 64-bit architecture, multi-core and multiprocessing were also introduced including Windows XP, Windows Vista, Windows 7, 8 and Windows 10.

Lesson 3

Topic 3: Windows Market Role

Several competitors of Windows OS like UNIX, Linux etc. exist in the market; however, Windows has its own unique status in the market. It has several significant advantages over other operating systems.

Above 90% PCs are based on Intel’s processors and Windows is the most appropriate OS for Intel PCs. In the world of desktop, the most dominant OS is the Microsoft Windows which enjoys a market share of above 80%. Windows is not confined to the desktop, it also has support for diverse platforms including multi-core, multiprocessing, servers and mobiles etc.

Due to its dominance role, certain applications and software development tools are available in the market that can easily integrate with Windows OS and can develop windows applications ranging from small scale to enterprise level.

One of the key features of Windows OS is its rich GUI that makes its use very convenient. This interface can be easily customized according to the local setup. The size, color and visibility of graphical interface objects can also be changed by the user.

Compared to other operating systems, certain modern features exist in Windows due to which most of the developers develop their applications for Windows targeting the huge market of Windows.