4.4. Evolution and characterization of operating systems

Tube computing devices were created in the mid-1940s. At this time, the OS was not used, all tasks were solved manually by the programmer using the control panel.

In the mid-1950s. semiconductor elements were invented and started to be used; in this connection, the first algorithmic languages ​​and the first system programs — compilers, and then the first batch processing systems appeared. These systems became the prototype of the modern OS and were the first system programs for managing the computational process.

In the period from 1965 to 1980, there was a transition to integrated circuits.

The emergence of BIS has led to a sharp reduction in the cost of chips. The computer became available to the individual, which led to the PC era.

For the mid-1980s. characterized by the development of PC networks running a networked or distributed OS.

The operating system is a major part of the network software, it constitutes the environment for running applications and determines how efficiently they will work. The main requirement for modern operating systems is the ability to perform fundamental functions, in particular, efficient resource management and provide a convenient interface for the user and application programs. The operating system is designed to implement multi-program processing, virtual memory, support a multi-window interface, and others. In addition to the functional, OS also has market requirements.

1. Extensibility. The system should be written in such a way that it can be easily amended and modified without disturbing its integrity.

2. Portability. Without much difficulty, the OS should be migrated from hardware of one type to hardware of another type.

3. Reliability and fault tolerance. The operating system must be protected from internal and external errors, failures and failures; its actions should be predictable, and applications should not destroy it.

4. Compatibility. The system must have the means to execute application programs written for other operating systems. The user interface of the system must be compatible with existing systems and standards.

5. Security. The system must have the means to protect the resources of some users from others.

6. Performance. The system should have as good speed as the hardware allows.

Network OS is evaluated by the following criteria:

• the ability to share files and printers with high performance;

• effective implementation of client-server architecture-oriented application programs, including manufacturers' application programs;

• availability of conditions for work on various platforms and with various network equipment;

• ensuring integration with the Internet, i.e., support for appropriate protocols and Web server software;

• remote access to the network;

• organization of internal e-mail, teleconferences;

• access to geographically scattered, multi-server networks using directory services and names.