|
Arabic
Bengali
Chinese
English
French
German
Hebrew
Hindi
Italian
Japanese
Korean
Malay
Polish
Portuguese
Spanish
Turkish
Ukrainian
Vietnamese|
HISTORY OF TECHNOLOGY, TECHNOLOGY, OBJECTS AROUND US
Personal Computer. History of invention and production
Directory / The history of technology, technology, objects around us A computer is a device or system capable of performing a given, well-defined, variable sequence of operations.
The computer these days has taken the same place as the phone, car and TV. But, apparently, these are only the first harbingers of the total era of computerization that is coming in the coming decades. In all respects, the computer is a completely extraordinary phenomenon. Perhaps no other technological invention before him showed itself so rapidly, did not develop so rapidly and did not permeate all spheres of our life so many-sidedly. Computers have already become indispensable in office work, business, military affairs, science, technology and hundreds of other professional activities. They are rapidly taking root in the fields of art, politics and sports. The importance that computers have managed to occupy in the private life of people, in their recreation and mutual communication is enormous. But all this, perhaps, serves only as a preparation or the first harbinger of a grandiose information revolution that is coming in the coming decades. Because it is the computer that will have to play the role of that magic key, that magic window, with the help of which each individual, through global computer networks, will be able to access all the wealth of information accumulated by mankind. Although in our time computing operations are by no means the main and, in any case, not the only area of application of the computer, historically it owes its appearance to the development of computer technology. The first generation of computers, these hard and low-speed computers, were the pioneers of computer technology. As we remember, they quickly disappeared from the scene, never finding a wide commercial application due to unreliability, high cost and difficult programming. They were replaced by computers of the second generation. Semiconductors became the element base of these machines. The switching speeds of the first imperfect transistors were already hundreds of times higher than those of vacuum tubes, reliability and efficiency were also several orders of magnitude higher. This immediately expanded the scope of the computer. It became possible to install them on ships and aircraft. The demand for computers grew rapidly. The first serial computers on transistors appeared in 1958 simultaneously in the USA, Germany and Japan. In 1962, the mass production of integrated circuits began, but already in 1961 an experimental computer was created on 587 microcircuits. In 1964, IBM launched the production of IBM-360 machines - the first mass series of computers based on integrated elements. For the first time then, it became possible to link machines into complexes and, without any alterations, transfer programs written for one computer to any other of this series. So the standardization of hardware and software of computers was carried out. In total, the series included 9 machines of different levels of complexity with an addition operation time from 206 to 0,18 microseconds. For several years, 19 thousand computers of this series of different classes were sold. From this we can conclude that with the advent of machines of the third generation, the demand for computers has grown even more. They began to acquire many industrial and commercial firms. Created in 1971, Intel's microprocessors were an extraordinary commercial success, since they provided a solution to a fairly large range of operational tasks at a low cost. In 1976, the first machines of the fourth generation on large integrated circuits appeared - the American Cray-1 and Cray-2 with a speed of 100 million operations per second. They contained about 300 thousand chips (microcircuits). So in a nutshell looked like the prehistory of the personal computer. No one planned the emergence of this type of machine. He fell, figuratively speaking, like snow on his head. It all started in the same 1976, when two enterprising twenty-year-old American technicians with no special education, Stefan Wozniak and Steve Jobs, created the first small but promising personal computer in a primitive workshop located in an ordinary garage. It was called "Apple" ("Apple") and was originally intended for video games, although it also had programming capabilities. Jobs later founded Apple Computer, which pioneered the mass production of personal computers. Demand for them exceeded all expectations.
In a short time, Jobs' firm grew into a large and prosperous enterprise. This forced other firms to pay attention to the personal computer market. Many models of "personal cars" of various concepts appeared on sale. In 1981, IBM released its first personal computer, the IBM PC. Its success all over the world was huge, which was largely due to the very good 16-bit microprocessor Intel-8088 and the superbly designed software from Microsoft. The next PC/XT model, released in 1983, had 640 KB of RAM, a hard drive, and high performance. In 1986, an even more advanced PC / AT model based on the Intel-80286 microprocessor appeared. By the end of the decade, IBM computers became the most massive and popular. What is a personal computer? Regardless of the complexity of a computer, its block diagram can be divided into three large sections: memory, processor, and peripheral equipment. The memory serves to store numbers and logical commands (which are also stored in it in a numerical code) and works in constant communication with the processor, and when necessary, it is connected to peripheral devices. Physically, the memory is divided into separate conditional cells, each of which contains exactly one number of a fixed length. A machine cell is characterized by a certain microstructure that determines how many binary units of information (bits) can be written into it. A bit corresponds to one bit of the cell. This part of the cell, as already mentioned, can be in one of two states - they correspond to the conditional values "zero" and "one". Eight bits form a larger unit of information - a byte, with which you can represent in memory one letter of the alphabet, a digit of the decimal system, as well as any punctuation mark or some other symbol. Each cell is assigned an address, knowing which you can get to it, enter a number into it or read it from the cell. The memory cells also store a program consisting of a set of instructions - elementary prescriptions for what the machine should do during each working cycle. Finally, memory is used to store the intermediate results of solving the problem. Memory performance is characterized by two indicators: capacity (that is, how many numbers encoded in binary form can be placed in it) and speed (that is, how quickly these numbers can be written to memory and retrieved from there again). Memory performance depends on the speed at which each cell switches from one state to another. The amount of memory and its speed, generally speaking, are in conflict with each other. Ceteris paribus - the more memory, the less its performance, and the greater the performance - the less memory. Therefore, in modern computers, memory is organized in the form of a multi-tiered structure. A distinction is usually made between main memory and external memory. Main memory, in turn, consists of two parts: random access memory (RAM) and read-only memory (ROM). The first, highest level, is formed by RAM directly connected to the processor. In random access memory, the minimum access time to data stored in memory is achieved. The second echelon of memory - read-only memory - is connected to the RAM in case of its overload. It serves as a "quick reference", which the microprocessor accesses from time to time for the necessary information, or application programs. Its speed is several orders of magnitude lower than in RAM, but it has a much larger volume. In addition, when the computer is turned off, information from it is not erased. External memory refers to various devices capable of storing large amounts of information. These are magnetic disk drives, magnetic tapes, etc. Their performance may be several orders of magnitude lower than in main memory devices, but they can have a huge capacity - several million or billion bytes. Initially, a conventional cassette tape recorder served as an external memory device for a computer. Over time, floppy disks (soft magnetic disks resembling a small plate enclosed in a special envelope; their capacity is about 1-1,4 MB) began to become more widespread. Information from computer memory to a floppy disk and from a floppy disk to computer memory is written off using a disk drive - a special data input-output device. One tape cassette can store about as much information as a floppy disk, but the time it takes to access a program or data element for magnetic tape drives is much longer than for a magnetic disk drive. This is understandable, since the information on the tape is recorded as one long sequence of bits, and to read the necessary information, you need to rewind the entire tape. Now, hard drives (hard drives) are used as an external memory device. The most important unit of any computer is the processor. Its role is played in a computer by a microprocessor - an integrated circuit on a silicon crystal. The microprocessor implements the most complex logic circuit, which can be considered the "heart and brain" of the machine. The very name of the block speaks of its active functions. Indeed, the processor is engaged in processing, in accordance with the program, the information that is contained in the memory. In each working cycle, the processor performs one logical or computational operation. The basis of the processor is logical circuits: control unit, arithmetic logic unit and registers. The control device controls the operation of all computer components; the input of this circuit receives command codes from the memory, which are converted into a set of control pulses sent to the desired points of the computer circuit. The operation of the control device can be likened to the actions of a conductor in an orchestra, who, guided by the notes of a musical work, with the help of a conductor's baton, indicates to groups of musicians and individual musicians the beginning and end points of parts of the musical work being performed. The arithmetic-logical unit is designed to perform arithmetic and logical operations. Registers are electronic digital devices for temporarily storing information in the form of a binary number. If the register can simultaneously store 8 bits (eight binary characters) it is called eight-bit. If there are 16 sixteen bits, and so on. Registers are specialized in their functions. Some are intended only for storing information, others act as counters of executed commands, others serve to remember the addresses of executed commands, etc. Computer peripheral equipment is a large family of simple and complex devices, the main significance of which is to provide communication between the computer and the outside world. First of all, the computer must be endowed with the ability to perceive information. This is what input devices do. The main input device is the keyboard. It contains alphanumeric keys for entering numbers and texts, as well as keys for cursor control, switching modes and registers, and for other purposes. The keys on the keyboard are arranged almost the same as on a typewriter. The main device for displaying information is a display (monitor). The mouse is of great importance in the dialogue between the user and the computer. A mouse is a small device that slides on a flat surface. The relative coordinates of its movement are transmitted to the computer and processed in such a way as to control the movements on the display screen of a specially selected marker, which is called the cursor. This way of positioning and specifying objects on the screen is very convenient. With this organization of the dialogue, several pre-composed versions of commands are displayed on the screen. By pointing the cursor at one of them, the user gives a command. Thus, a person who does not even have a remote idea of programming can successfully work on a computer. The most widely used output device is a printing device, or printer. But it can also be a graph plotter (plotter) for displaying graphs and drawings. Until recently, dot matrix printers were the most widely used. In them, the image of individual signs is built on a matrix of 9 by 9 dots and is formed by blows through the ink ribbon of the thinnest rods. The number of rods is usually 9, so that the points within their matrix touch, forming continuous lines. It is easy to create arbitrary fonts on these printers, as well as output any graphics. Higher print quality is provided by inkjet printers that allow multiple levels of brightness and color printing. The principle of operation of such printers is based on the fact that the smallest droplets of ink are ejected onto the paper by the control of the program from a horizontally moving nozzle, forming the necessary image. Laser printers provide high quality printing at high speed. Like photocopiers, laser printers use a xerographic printing process, but the difference is that the image is formed by directly exposing (illuminating) the photosensitive elements of the printer with a laser beam. Prints made in this way are not afraid of moisture, are resistant to abrasion and fading. The quality of this image is very high. As with any computer, a necessary and integral part of a computer is its software. It is almost impossible to work on it without the appropriate program. The most important class of programs for each computer should be considered its operating system, which supports the operation of all other programs, ensures their interaction with the hardware and provides the user with the ability to manage the computer in general. This system converts commands and actions performed by a person at a computer into long sets of short and simple commands that a computer can understand. There are not many operating systems. In 1974, the CP / M system was developed, which marked the beginning of the creation of operating systems for personal 8-bit computers. The success of this system was due to its extreme simplicity and compactness, as well as the fact that it required very little memory. In 1981, along with the IBM PC computers, the MS-DOS operating system appeared - the Microsoft disk operating system, which became the main operating system for 16-bit computers. The first Windows 95 system from Microsoft was released in 1995. Its distinguishing features were: a new user interface, support for long file names, automatic detection and configuration of Plug and Play peripherals, the ability to run 32-bit applications and the presence of TCP / IP support directly in the system. Windows 95 used preemptive multitasking and ran each 32-bit application in its own address space. Apple developed the Mac OS (Macintosh Operating System) for its Macintosh computers. Early versions of Mac OS were only compatible with Macs based on Motorola 68k processors. Subsequent versions were compatible with the PowerPC (PPC) architecture. Since the mid-2000s, Apple has been using Intel processors in its computers. According to the Mac OS EULA, installation of the OS is only allowed on Apple computers. Author: Ryzhov K.V.
▪ Shuttle and Buran space shuttles ▪ Phone
Artificial leather for touch emulation
15.04.2024 Petgugu Global cat litter
15.04.2024 The attractiveness of caring men
14.04.2024
▪ Liquid Cooled TeamGroup M.2 SSD ▪ Named the maximum life expectancy of a person ▪ MDmesh K5 - new 900V MOSFETs from STMicroelectronics ▪ Video card GIGABYTE GeForce GTX 1650 D6 Eagle OC
▪ site section Regulators of current, voltage, power. Article selection ▪ Wiener Norbert article. Biography of a scientist ▪ article Which world-famous drummer plays after losing his left arm? Detailed answer ▪ article Alternative energy sources. Directory
Home page | Library | Articles | Website map | Site Reviews
www.diagram.com.ua |
We recommend interesting articles Section 
See other articles Section 
Latest news of science and technology, new electronics:
All languages of this page