Basics of the user in the personal computer operating environment 4.1. Operating Systems

An operating system is a series of control programs that are used as an interface between PC components and provide the most efficient implementation of computer resources. The operating system is the basis of the system program that is loaded when the computer is turned on.

The main functions of the OS include:

• receiving commands or tasks from a PC user;

• accepting and applying program requests to start and stop other programs;

• loading into the OP suitable for the execution of programs;

• protection of programs against mutual actions against each other, ensuring data integrity, etc.

According to the types of user interface (set of techniques that ensure the interaction of PC users with its applications), the following operating systems are distinguished:

a) command interface — issuing on-screen prompts for entering commands from the keyboard (for example, MS-DOS OS);

b) a WIMP interface (or a graphical interface — a graphical representation of images that are stored on a hard disk (for example, Windows operating systems of various versions);

c) SILK (Speech Image Language Knowledge) interface - using voice commands for interaction between a PC user and applications. This type of OS is currently in its development stage.

According to the task processing mode , the following operating systems are distinguished:

a) providing single-program mode, that is, a method of organizing calculations, in which at one time they are capable of performing only one task (for example, MS-DOS);

b) working in multiprogram mode, when the organization of calculations on a single-processor machine creates the appearance of running several programs.

The difference between multiprogramming and multi-tasking modes is that in multiprogramming mode, several applications are executed in parallel, and the user does not need to worry about the organization of their work, the OS takes these functions. In multitasking mode, application programmers should provide parallel execution and interaction of applications.

In accordance with the support of a multi-user OS, the following are divided:

a) single-user (MS-DOS, earlier versions of Windows and OS / 2);

b) multi-user (network) (Windows NT, Windows 2000, Unix).

The main difference between multi-user OS and single-user OS is the availability of means to protect each user's information from unauthorized access by other users.