Cadbury Schweppes

History and background

Windows XP

The story of windows begins with a very different operating system developed by Microsoft for the first IBM personal computer and referred to as MS-DOS or PC-DOS. Which was released on August 1981. Now Microsoft has come with powerful operating system called ‘Windows Vista’. The one before Vista was Windows XP.

Windows XP was released on October 25, 2001, which is available in Home, business desktops, notebook computers and media centers editions. The letter ‘XP’ stand for experience. Codenamed ‘whistler’ after Whistler, British Columbia, as many Microsoft employees skied at the Whistler-Blackcomb ski resort during its development, windows XP is the successor to both windows 200 and windows ME, and is the first consumer-oriented operating system produced by Microsoft to be built on the Windows NT kernel and architecture.(Wikipedia)

The most common editions of the operating system are Windows XP Home Edition, which is targeted at home users, and Windows XP Professional, which has additional features such as support for Windows Server domains and dual processors, and is targeted at power users and business clients. Windows XP Media Center Edition has additional multimedia features enhancing the ability to record and watch TV shows, watch DVDs, and listen to music. Windows XP Tablet PC Edition is designed to run the ink-aware Tablet PC platform. Two separate 64-bit versions of Windows XP were also released, Windows XP 64-bit Edition for IA-64 (Itanium) processors and Windows XP Professional x64 Edition for x86-64 processors. (Wikipedia) Though these editions are based on the same core technology, some features are unavailable in some editions.

UNIX SVR4

System V Release 4.0 was announced on October 18, 1988 and was released in 1990. It developed jointly by AT&T and Sun Microsystems combines features from SVR3, 4.3BSD, Microsoft Xenix System V, and SunOS. It was almost a full rewrite of the system V kernel and produces a clean, if complex, implementation. New features in the release include real-time processing support, process scheduling classes, dynamically allocated data structures, virtual memory management, virtual file system and a preemptive kernel (William Stallings).

SVR4 draws on the efforts of both commercial and academic designers and was developed to provide a uniform platform for commercial UNIX deployment. It has succeeded in this objective and is perhaps the most important UNIX variant. It incorporates most of the important features ever developed on any UNIX system and does so in an integrated, commercially viable fashion. SVR4 runs on a machine ranging from 32-bit processors up to supercomputers. (William Stallings)

Windows XP I/O

The I/O manger of windows XP is responsible for all I/O for the operating system and provides a uniform interface that all types of drivers can call. The I/O consists of four subjects:

Cache manger: It handles caching for the entire I/O subsystem. It also provides a caching service in main memory to all file systems and network components. It can dynamically increase and decrease the size of the cache developed to a particular activity as the amount of available physical memory varies.

File system drivers: The I/O manager treats a file system driver as just another device driver and routes message for certain volumes to the appropriate software driver for that device adapter.

Network drivers: Windows include integrated networking capabilities and support for distributed applications.

Hardware device drivers: These drivers access the hardware registers of the peripheral devices through entry points in windows Execute dynamic link libraries. A set of these routines exists for every platform that windows supports; because the routine names are the same formal platforms the source code of windows device drivers is portable across different processor.

SVR4 I/O

In UNIX, each individual I/O device is associated