Lesson on theme: THE ORIGIN HISTORY OF THE COMPUTER AND PROGRAMMING Рrepared by: Tynyshtykova M. T. Checked: Amitova Aktobe 2015
Computer Ø Computer - is a universal software-controlled electronic device for automatic processing, storing and transmitting information. Ø The principle of computer management software is that the program consists of a set of instructions stored in the memory of the computer and the computer automatically executes the program. Ø Program - a predetermined, clearly defined sequence of arithmetic, logical, and other operations. Ø The computer processes the information, executing programs which are developed by man and entered into the computer memory.
Babbage's Analytical Engine. In the first half of the XIX century. English mathematician Charles Babbage tried to build a general purpose computing device, ie computer (Babbage called his Analytical Engine). It Babbage first thought of the fact that the computer must contain the memory and controlled by the software. Babbage wanted to build your own computer as a mechanical device, and the program was going to ask via punched cards - cards out of construction paper with the information applied via holes (they at that time already widely used in the looms). However, to complete this work Babbage could not - it was too complicated for the technology of the time.
The first computers In the 40 years of the XX century. Several groups of researchers retry Babbage based technology XX century. - Electromechanical relays. Some of these researchers did not know anything about the work of Babbage and rediscovered his ideas again. The first of these was a German engineer Konrad Zuse, who in 1941 built a small computer based on the number of electromechanical relays. But because of the war Zuse works were not published. And in the USA in 1943 at one of IBM's American Howard Aiken created a more powerful computer called "Mark 1". He already allows evaluation hundreds of times faster than by hand (using an adding machine), and actually used for military calculations. SAGE, 1954
The advent of personal computers Initially, the microprocessors used in various specialized devices, such as calculators. But in 1974, several companies announced the creation of microprocessor-based Intel-8008 PC, ie the device performs the same function as the big computer, but designed for a single user. In early 1975 there was the first commercially distributed personal computer Altair-8800 microprocessor-based Intel-8080. Although the possibility of it were very limited (memory was only 256 bytes, the keyboard and the screen is missing), his appearance was greeted with great enthusiasm in the first months has sold several thousand sets of machines. Buyers have implemented this computer with additional devices: a monitor for displaying information, keyboard, memory expansion units, etc. Soon these devices were produced by other companies.
Apple Computer Ø In late 1975, Paul Allen and Bill Gates (the future founders of the company Microsoft) created for the computer "Altair interpreter Basic, allowing users to simply communicate with the computer and easy to write programs for it. This also contributed to the popularity of personal computers. Personal computers were sold in the complete set, with a keyboard and monitor, the demand for them was ten, and then hundreds of thousands of pieces god. V 1976 a new company Apple Computer entered the market with the Apple I computer costing 666 dollars. Its motherboard was screwed to a piece of plywood, and the body and the power supply was not voobsche. No appeared in 1977 the Apple II became the prototype of most subsequent models, including the IBM PC. Apple I, 1976 г
Machine code. Аssembler History of programming languages began with the development of machine language: the language of logic zeros and ones. Record in this language was very difficult and tedious. Therefore, in the late 40's to facilitate the work of the first programmers was created assembler language. Instead of binary digits denoting a particular command, write short word or acronym. Assembler language programmers call low-level programming, because it is close to machine language - language programming of the lowest level. Program in assembler depend on the characteristics of the particular processor, so it is called a machine-oriented language. Despite the complexity of writing programs and the need for knowledge of the computer program in assembly language is the most effective and operational.
Structured programming v Within a decade, was created quite a number of new languages: algol (1958) - for writing algorithms composed of separate blocks; cobol (1959) - for mass data processing in the areas of management and business; basic (1965) - for writing simple programs, learning the basics of programming. However, very few of them were structured. It was also created many other specialized languages: lisp, prolog, forth, PL / 1. . . v Special attention deserves the language pascal (1970) (named after the scientist blaise pascal), which can be used both for training and for the solution of problems of varying complexity. Program it is easy to read, so you can quickly find and fix bugs, as he had a well-defined layout. This has led to its widespread use, and even now it is still actively used in educational institutions. v Very successful step was introduced in 1972 in c. It combined the achievements of many languages, and has a large number of different innovations. Opportunities, structuring, and the relative simplicity of the study allowed him to quickly gain recognition and become one of the major languages.
Object-oriented programming (OOP) In the '70 s created the foundations of a new object-oriented programming. The PLO was the result of an ideology of procedural programming, where data and routines (procedures, functions) processing are not formally linked. The basic concepts of OOP are: Class - model are not an existing object. In fact, he describes a device object, as his scheme. Object - an instance of the essence in the address space of a computer system that appears when you create an instance of the class. Abstract - giving object characteristics that clearly define its borders, unlike all other objects. The basic idea is to use a method to separate components of the data objects in their implementation details a more simple objects. Encapsulation - combine the properties (data) and methods (subroutine) in the class in order to conceal the object data from the rest of the program and ensure the integrity and, independently of the object. (change the properties of an object iozhno only through special class methods) Inheritance - the mechanism of language, which allows to describe a new class based on an existing class (or classes) with the addition of new properties and methods. Polymorphism - property of the system to use objects with the same interface without information about the type and the internal structure of the object. First programming language, which proposed the principles of object-orientation, was Simula. At the time of its appearance in 1967, there have been proposed a revolutionary idea: objects, classes, virtual methods, etc. , but it's not been adequately appreciated by his contemporaries. However, most of the concepts were developed by Alan Kay and Dan Ingalls language Smalltalk. It became the first widely distributed object-oriented programming language. Currently, the number of application programming languages that implement object-oriented paradigm, is the largest in relation to other paradigms. The main languages that support the concept of OOP: C ++, C #, Object Pascal (Delphi), Java.
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