Later a gui known as dos shell was also added to this

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: of its users as a complete programming environment, not just an operating system. MS-DOS MS-DOS stands for Microsoft Disk Operating System. It is a single-user operating system for IBM and IBM-compatible personal computers. It was introduced in 1981 jointly by Microsoft and IBM and was the most popular operating system for personal computers in the 1980s. Its popularity started reducing in the 1990s with the launch of Microsoft Windows operating system. Structure of MS-DOS MS-DOS is structured in the following three layers: 1. BIOS. BIOS stands for Basic Input Output System. It contains device drivers for the standard devices such as keyboard, disk, floppy, printer, and display monitor. It also contains the basic low-level services such as time-of-day and system configuration analysis. Having the hardware-dependent services in BIOS ensures that the other higher-level operating system services can be offered in a hardware-independent manner, enabling those operating system services to be easily portable to other machines. The BIOS is usually supplied by the computer manufacturer, rather than by Microsoft, and is generally located, in part, in a ROM, which is a non-erasable memory. When the computer's power is switched on, control is transferred by hardware to the bootstrap procedure of the BIOS in ROM. The bootstrap procedure carries out some hardware tests to check whether the memory and other hardware devices are functioning properly. If the hardware test passes successfully, the bootstrap procedure loads into the memory a small portion of the operating system from the disk. This part of the operating system then loads the rest of the memory resident portions of the operating system into memory from the disk. This step-by-step process of loading the operating system into memory is known as booting the system. 2. Kernel. This layer contains all the modules for process management, memory management, and file management. These modules are written in machineindependent manne...
View Full Document

This document was uploaded on 04/07/2014.

Ask a homework question - tutors are online