The software world

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At each inclusion of the computer by the very first program with which computer operation automatically starts, always there is an operating system.
The operating system boots from a disk in a computer memory. Thus DOS welcomes the user on the screen and invites to start operation on the personal computer. Further under control of DOS and other programs there is an operation various internal and peripherals of the personal computer. The first serious refinement MS-DOS (version 2.0) has been fulfilled in 1983
The new operating system though developers managed to provide complete MS DOS compatibility 1.0 has actually been released. In system MS-DOS 2.0 have been included
Following innovations:
· support of diskettes with the raised bit density and, the main thing, appeared to
To this time of hard disks;
· an outline of directories (come from system UNIX) together with group
Commands of its support (CD, MD, RD, etc.);
· an input-output redirection, pipelines and filters (too resources, characteristic

Application packages

Numerous software for solution of various types of computing tasks can be divided into 4 groups:
- Separate applications;
- Libraries of applications;
- Application packages;
- The integrated program systems. We will consider one after another each of these groups. The separate application is written, as a rule, in some general-purpose language of programming (Paskal, etc.) and intends for solution of the concrete applied task.

Examples can be the program of solution of system of the linear algebraic equations for that or other numerical method, the program of calculation of eigenvalues of a matrix etc. Authors of such programs are the application programmers specialising: in appropriate subject domains. The application can be realised in "sort of a set of units, each of which fulfils some independent function. For example, the program of calculation the proprietor of values of a matrix can include units, - realising conversions of a matrix from one, representation forms in another input and output of the data, processing of emergencies with output of diagnostic messages to the user and other operations.
The library represents a set of separate programs, each of which solves some applied task or fulfils certain auxiliary functions (a memory management, an exchange with peripherals, etc.). Libraries of programs have proved as an effective remedy of solution of computing tasks. They are intensively used at solution of scientific and engineering tasks by means of the computer. Conditionally they can be divided into libraries of wide application and specialised libraries.

The programs which are a part of library of wide application, are intended for problem solving from various subject domains.
Specialised libraries are oriented to solution separate, occasionally enough narrow, classes of tasks.
Transition from development of separate applications to creation of libraries of programs has put before developers a number of problems both system, and applied character. To number of the main problems arising at various stages of designing of library, problems of ordering, documenting, testing and portability concern.

The ordering problem consists in splitting of library into sections and subsections according to classification of back of a subject domain and methods of their solution. The choice of uniform rules of the name of programs (taking into account modification and library development), uniform forms of representation and the name similar objects, the uniform circuit of error checking etc. here enters.

The documenting problem consists in compilation of uniform rules of the description of programs of library. Presence of the qualitative documentation essentially simplifies access to separate programs, the interaction organisation between programs, inclusion of new programs. The important role at solution of the specified problem is played by resources of automation of the documenting, providing wide application of templates (for banner pages, text fragments, etc.), usage of texts of programs of library for the automated compilation of the documentation etc.