Lesson topic: “Digital information processing devices: digital video camera. Digital devices

During the development of digital technology, computers of a wide variety of types have been developed. Many of them have long been forgotten, but others have had a strong influence on the development of modern computing systems. Here we will give a brief overview of some of the stages in the development of computers to show how human thought came to the modern understanding of computer technology.

Devices that facilitate counting or memorizing its results have been known for a long time, but we will only be interested in computing devices that automatically execute programs embedded in them. Therefore, we do not consider here such devices as abacus, mechanical adding machines and electronic calculators.

The first stored program calculator was built by a French scientist Blaise Pascal in 1642, it was mechanical with a hand drive and could perform addition and subtraction operations. German mathematician Gottfried Leibniz in 1672 he built a mechanical machine that could also do multiplication and division. For the first time a machine working according to the program was developed in 1834 by an English scientist Charles Babbage. It contained a memory device, a computing device, a punched card input device and a printing device. The commands were read from a punched card and performed data reading from memory into a computing device and writing the results of calculations into memory. All devices of Babbage's machine, including memory, were mechanical and contained thousands of gears, the manufacture of which required precision not available in the 19th century. The machine implemented any programs written on a punched card, so for the first time a programmer was required to write such programs. The first programmer was an Englishwoman Ada Lovelace, in honor of which the programming language Ada was already named in our time.

In the XX century. electronics began to develop and its capabilities were immediately adopted by the developers of computers. The countdown of generations of digital computers begins with the construction of computers, the basic system of elements of which was built on electronic components. Note that dividing the period of development of digital technology into stages is mainly associated with the transfer of the basic system of elements to new technologies for the production of electronic components.

First generation -

vacuum tubes (1945-1955)

The basic system of elements of this generation of computers was based on vacuum tubes. Their use determined both the advantages and disadvantages of digital devices. Electronic tubes provided a high switching speed of logic elements, which increased the speed of computation in comparison with attempts to create a computer, the basic element of which was built on the basis of an electromechanical relay. Vacuum tubes were durable enough to provide reliable computer operation. Unfortunately, there were plenty of shortcomings in tube computers too. Vacuum tubes operated with voltages of tens of volts and consumed a lot of energy, in addition, the size of vacuum tubes, according to modern microelectronic concepts, was huge - several tens of cubic centimeters. Thousands of logical elements were needed to build a computer, so the size of tube computers in terms of the occupied area was tens of square meters, and the power consumption ranged from units to tens or even hundreds of kilowatts. This power led to overheating of the lamps, which were placed rather compactly, and posed the task of effectively cooling the electronic components of the machine. The processing speed of information in tube machines ranged from several hundred to several thousand operations per second.

Second generation - transistors (1955-1965)

Semiconductor devices - transistors were invented in 1948. They differed from vacuum tubes in small size, low supply voltage and low power consumption. All these advantages of semiconductor devices have revolutionized the electronics industry. Miniature transmitting and receiving radio and television devices began to appear, it became possible to embed control devices directly into control objects, etc. The new element base for computers based on transistors has revolutionized the production of computers. A significant reduction in size, power consumption and cost reduction made it possible to create computer architectures with great functionality, to dramatically increase the speed of computers to hundreds of thousands and even millions of operations per second. The increase in productivity was provided both due to the higher speed of operation of transistors in comparison with vacuum tubes, and by introducing several processing devices operating in parallel into the computer. The area required to accommodate a computer was reduced to_ a few square meters, attempts were made to make desktop versions. The decline in cost has increased the number of potential computer users. Large firms for the production of general-purpose computers have appeared: International Business Machines (IBM), Control Data Corporation (CDC) Digital Equipment Corporation (DEC) and others. It should be noted the PDP-8 computer of the DEC company - the first mini-computer with a common bus, which had a great influence on the development of personal computer architectures.

Third generation - integral schemes (1965-1980)

Semiconductor elements and other electronic components were produced by the electronics industry as separate elements. So, the semiconductor crystal on which the transistor was located was enclosed in a special metal or plastic case. The requirement to reduce the size of electronic

devices led to the fact that at first semiconductor devices began to be produced in an open-frame design, and then in 1958 an attempt was made to place all the components of one functional unit in one semiconductor crystal. This is how integrated circuits (ICs) appeared, which made it possible to dramatically reduce the size of semiconductor circuits and reduce power consumption. On the basis of ICs, mini-computers were built, which were made in the form of a single rack and peripheral devices. The power consumed by an IC computer has been reduced to hundreds of watts. The increase in the speed of nodes built on ICs made it possible to increase the speed of computers to tens of millions of operations per second. The electronics industry began mass production of electronic components on ICs, which made it possible to reduce their cost and dramatically reduce the cost of the hardware component of computers. Reducing the cost has led to the development and practical implementation of powerful computing systems using parallel processing: multiprocessor and pipeline computers.

4th generation - very large scale integrated circuits (since 1980)

The microminiaturization of electronic devices has led to the emergence of a new industry - microelectronics, which belongs to the field of high technologies. Using the latest scientific and technical achievements of physics, chemistry, crystallography, materials science and even astronautics (in zero gravity, semiconductor crystals of very high purity can be obtained), we have achieved placement on one crystal several square millimeters in size, first hundreds, then thousands and finally millions of transistors and others electronic components. Now the semiconductor circuit no longer contained a set of several logical elements, from which the functional units of the computer were then built, but entirely functional units and, first of all CPU, which, given its size, was named microprocessor, external device controllers - controllers external devices. Such integrated circuits were first named large integrated circuits(BIS), and then very large scale integrated circuits(VLSI).

The result of such a rapid development of microelectronics was the emergence of single-board computers, where on one board, several tens of square centimeters in size, were placed several VLSI, containing all the functional blocks of the computer. Single-board computers were built into various industrial, medical and household devices for operational information processing and control. The cost of single-board computers fell so much that it became possible to acquire them by individuals, English engineers took advantage of this opportunity Steve Jobe and Steve Wozniak. Using the functional units produced by the industry: a micro-computer board with a processor and memory, a keyboard, a display, they assembled a cheap desktop computer - microcomputer. Its appeal to non-professional users was that it was a ready-to-use device containing all the necessary hardware and software to operate. This microcomputer was named App! E and became the first in the world personal computer.

A large company engaged in the production of powerful computing systems became interested in personal computers, which became widespread in the computer market - 1VM, and decided to launch the production of her own model of a personal computer. Together with the company Intel, which developed the microprocessor kit, and Microsoft, which equipped the computer with an operating system MS DOS, IВМ created a personal computer IBM RS. The significant potential of the IBM company made it possible to produce a huge number of such computers in a short time. Their attractive price for buyers and some innovations, for example, a larger, compared to the personal computers of other companies produced at that time, the amount of RAM, allowed the IBM PC to become the most popular personal computer in the world.

2.6. Computer architecture for concentrated information processing

A modern computer consists of several functional units: processor, memory, device controllers, etc. Each node is a complex electronic device that can include millions of logic gates. For a better understanding of the principle of operation of each node and the computer as a whole, the concept of levels of computer representation is introduced.

Digital logic level - the level of logical circuits of the basic system of elements.

Microarchitectural level- the level of organization of information processing within the functional unit. This includes registers for various purposes, a device for processing incoming commands, a data conversion device, and a control device.

Command level- a set of functional units and connections between them, a system of commands and data transmitted between devices.

The set of blocks, connections between them, data types and operations of each level is called level architecture.

Command-level architecture is commonly referred to as computer architecture or computer organization. In this section, we will look at various computer architectures. Other layer architectures will be discussed in the following sections.

2.6.1. Fixed device architectures

Computers with concentrated processing These are computing systems in which one or more processing devices (processors) are compactly located and use internal data transmission buses for information exchange. Computers of the first and second generation had a closed architecture with a limited set of external equipment. This architecture is typical for computers, the basic system of logical elements of which is built on discrete electronic components (vacuum tubes, transistors). The introduction of any additional functional block in such architectures was associated with an increase in power consumption, occupied space and dramatically increased the cost of the entire system. Therefore, a computer made according to this architecture did not have the ability to connect additional devices that were not provided by the developer.

An enlarged diagram of such a computer architecture is shown in Fig. 2.9. The operative memory stores commands and data of executable programs, the ALU provides not only numerical processing, but also participates in the process of input-output of information, carrying out its entry into the operative memory. An input / output channel is a specialized device that operates on commands given by a control device. The channel allows the connection of a certain number of external devices. The control unit ensures the execution of program commands and controls all the nodes of the system.

Rice. 2.9. Closed-circuit computer architecture

Computers of this architecture are efficient at solving purely computational problems. They are poorly suited for the implementation of computer technologies that require the connection of additional external devices and a high speed of information exchange with them.

6.2. Computing systems with open architecture

In the early 70s. by DEC (Digital Equipment Corporation) a computer of a completely different architecture was proposed. This architecture made it possible to freely connect any peripheral devices, which immediately interested the developers of control systems for various technical systems, since it provided free connection to a computer of any number of sensors and actuators. The main innovation was the connection of all devices, regardless of their purpose, to common bus transmission of information. The devices were connected to the bus in accordance with bus standard. The bus standard was a freely distributed document that allowed peripheral equipment manufacturers to develop controllers for connecting their devices to buses of various standards. The architecture of an open-type computer based on the use of a common bus is shown in Fig. 2.10. General management of the entire

Modern digital devices: touch screens scanners cameras video cameras mobile phones web cameras document cameras video projectors wireless data transmission devices video surveillance systems e-books digital microscopes

Touch screens can be equipped with televisions, computer monitors and other screen devices. They can be installed in payment terminals, in equipment for trade automation, in pocket computers, in operator panels in industry.

Scanning devices A scanner is a device designed to enter into a computer various color and black-and-white images (photographs, drawings, slides), as well as text information from a sheet of paper, from a page of a book or magazine. The scanner is used when there is a need to enter text and / or a graphic image from an existing original into a computer for its further processing (editing, etc.).

Scanner is a device for entering information from paper into computer memory and further editing text or images.

Fields of application of cameras Widely used in the printing industry, scientific research, medicine, geology, forensic science. In these and many other industries, it is quite often necessary to obtain images almost instantly, followed by processing and sending them over long distances via the Internet.

Webcams are digital cameras capable of capturing images in real time, which are then transmitted over the Internet or other video application.

A document camera is a special video camera. It is used when it is necessary to show something small that exists in one copy (books, pictures, images from a microscope). Connects to TV, projector, computer.

E-books are classified as a type of tablet computer. Their appearance is due to the development and specialization of tablet computers in general. Some modern devices are equipped with a touch screen and have an extended set of functions, and allow not only reading, but also editing text.

Benefits Compact and portable. One device can store hundreds and thousands of books. In addition, the device is usually smaller and lighter than a paper book. Image settings. At the request of the user, you can change the font style and size and the output format (in one column or in two, portrait or landscape). The ability to change the font size makes it possible to read books for people who are not allowed to read by the small, unregulated font of paper books. Additional features. The device can be used for text search, hyperlinks, display of temporary selections and notes, electronic bookmarks, a dictionary.

Benefits Built-in programs - speech synthesizers allow reading texts. The e-book allows not only reading texts, but also displaying animated pictures, multimedia clips or playing audiobooks. The cost of the text. Many texts in electronic form are free of charge or cheaper than in paper form. Availability. If you have an Internet connection, the texts are available for download at any time from the respective sites (electronic libraries).

Benefits Environmentally friendly. To read texts in an e-book, you do not need paper, for the production of which forests are cut down. Safe for asthmatics, allergy sufferers, house dust and paper dust.

Disadvantages E-readers with TFT screens have an adverse effect on human vision, similar to a computer. Relatively poor image quality, not comparable to paper books published on expensive high quality paper [source unspecified 42 days]. Like any electronic device, e-book readers are much more sensitive to physical impact (damage) than paper books. High price. Some publishers release the electronic version of the book with a delay. Some of the books are not officially published as an electronic version at all.

Disadvantages In some models [clarify] DRM is used, which imposes restrictions, including on fair use, so the use of DRM leads to a situation that any book cannot be read on any device. One of the striking examples was the remote deletion of legally purchased books from users' devices. However, since it is not difficult to buy an e-book that reads formats that do not support DRM (for example, fb 2, rtf, txt, etc.), and not all e-books have communication capabilities, this can hardly be considered a disadvantage of e-books. as a class of devices. Devices for reading e-books require periodic recharging of the built-in rechargeable batteries (batteries).

Digital microscope A digital microscope is a microscope equipped with a digital imaging system that transfers images to a computer. A digital microscope makes it possible not only to observe micro objects, but also to document images using the input system installed on the microscope, and, if necessary, carry out measurements on images and analyze them using software.

Digital Microscope Digital video cameras, digital cameras, or analog input systems can be used to transfer images from a microscope or stereomicroscope to a computer. With the help of these devices, the image from the microscope is transferred to a computer for subsequent archiving or processing, if necessary. The choice of an input system depends on the tasks to be solved and the requirements for image quality.

Digital microscope Digital microscopes allow you to transmit images with various magnifications from several times magnification to hundreds of thousands of times magnification

A graphics tablet, or digitizer, is designed to enter graphic images into a computer, and is used when working with professional graphics and CAD programs, as well as for creating or copying drawings or photographs. It allows you to create drawings just like you would on a piece of paper. This input device consists of a tablet and a pointer. The image is converted to digital form, hence the name of the device (from the English digit - number).

Graphic tablet The principle of operation of the digitizer is based on fixing the coordinates of the cursor on the surface of the tablet using a built-in mesh consisting of wire or printed conductors. The device allows you to convert the movement of the pointer on the tablet into vector graphics. The digitizer accurately determines the absolute coordinates of the pointer on the tablet and translates them into the coordinates of a point on the monitor screen.

Graphic tablet Special circular cursors and pens are used as pointers. Like mice, pointers are provided with buttons. Cursors allow you to precisely set the coordinates of a point, they are often used when working in CAD. Pens are used when working in graphic editors, some of them are pressure-sensitive and allow you to change the parameters of the lines

Graphics tablet Tablets are rigid and flexible. Flexible tablets can be rolled up into a tube, they are convenient for transportation and storage, they are lighter, more compact and more expensive, but at the same time they have lower resolution and reliability than rigid ones.

Graphic tablet The result of the digitizer's work is reproduced on the monitor screen and, if necessary, can be printed out on a printer. Digitizers are usually used by architects and designers. The high price of professional digitizers with a large tablet format and a quality, balanced pointer limits the use of this input device

The digital information processing device and the "brain" of the entire publishing system is a computer, which is also a multilevel structure. It includes both processing elements (processor) and several types of information storage devices (RAM, hard disk, video memory), as well as a number of auxiliary elements (ports and other components)

Working with graphics, especially those intended for printing purposes, requires quite significant parameters of the computer used. Unfortunately (for the author only), the pace of technological progress in this area is unusually high, and the timing of writing, preparing, printing and distributing the book does not keep pace with them, so we will consider only the fundamental parameters that must be understood by every designer who sits down at a computer.

A personal computer is, first of all, a system unit, in which all the main components of a computer are located. The "brain" of a computer is microprocessor - the central device of the computer is an electronic circuit, several square centimeters in size, which ensures the execution of all application programs and the control of all devices. The microprocessor is made in the form of an extra-large (not in size, but in terms of the number of electronic components, the number of which reaches several million) integrated circuit located on a silicon plate.

Microprocessors can differ in the following main parameters:

Type (model) means the generation of microprocessors, for example, there are processors of the series, which are collectively called "286", "386", "486", "Pentium".

Clock frequency determines the number of elementary operations performed per second. It is measured in hertz (Hz). The clock speed is the main parameter that ensures the performance of the processor. The higher the processor type, the higher the clock speed. One of the first models of personal computers had a processor with a clock speed of 4.77 MHz, and the latest processors crossed the 1 GHz barrier.

Bit depth determines the number of bits transmitted simultaneously (synchronously) over data buses. Computer performance is also directly related to bit depth. This parameter changes in leaps and bounds: 8 bits, then 16, 32 bits, and finally 64-bit buses.

A computer as a whole is characterized by a number of other parameters that affect its performance.

Operational memory ( or RAM - random access memory) defines the amount of memory that the processor "disposes" of. Random access memory is fast and volatile (when the power supply is cut off, the information is completely lost) memory, in which the currently executable program and the data necessary for this are located. The higher this value, the more information can be simultaneously available for processing. The amount of RAM in a relatively short historical period has increased from 640 KB to tens of MB in modern systems (even in the most modest configurations). The performance (speed) of a computer directly depends on the amount of RAM.

Video memory - it is a separate RAM located on a dedicated video card. This memory contains data corresponding to the current screen image.

In a modern personal computer, the principle of an open architecture is implemented, which allows you to practically freely change the composition of devices (modules). A large number of peripheral devices are connected to the main information highway. In this case, it is very important that some devices can be replaced by others. Even the microprocessor and memory chips are no exception.

The hardware connection of peripheral devices to the information highway is carried out through a special block, which is called controller(sometimes called an adapter). And software control of the operation of external devices is also provided by special programs - drivers, which are usually integrated into the operating system.

Digital devices

Analog Devices

Analog devices include functional electronic units designed to perform various operations and conversions on analog signals. Structurally, analog devices can be represented as:

1. Two-terminal

It has 2 pairs of input terminals, to which the signal sources are connected, and the load is connected to the output terminals. It is a transmission link with control parameters.

Digital devices include functional units designed to perform operations on information objects in the form of digital signals. Code words are used to represent digital signals. Features: the simplest alphabet is used for construction - two letters, denoted by the symbols 0 and 1. The code word is a number in 2 SS. The number of letters in the codeword is fixed.

A word contains n letters or digits. In digital devices, the object of information is binary numbers, not functions of time.

Principles of functioning of digital devices:

1) To execute the command, a certain time is allotted, for this a clock pulse generator is used, it formulates the control signal

2) After the start of the operation, all input code words are converted to the required output

3) Output codewords are sent to storage in the digital system memory or to external devices to perform actions

Ways to handle codewords:

For the implementation of operations on code words, it is extremely important to them in the form of electrical signals. A potential way of presenting has gotten widespread. Logic zero corresponds to low signal level (voltage), logical one - high. Operations on codewords can be performed in two ways: sequentially (bit by bit) and in parallel.

The simplest converters of information:

A computer consists of millions of elements: transistors, diodes, registers, which are part of integrated circuits. But the study of the work of a PC is facilitated by the regularity of its structure, which means: a computer consists of a large number of the simplest elements, all of several types. The elements form a small number of typical circuits.

According to the degree of complexity of the functions performed, they are distinguished:

1) Elements - the simplest part that performs operations on individual bits. Distinguish logically (and, or, not, and-not, or-not), storage (triggers of various types) and auxiliary, serving to amplify and generate signals.

2) Nodes - consist of elements and perform operations on words. Distinguish between combinational and cumulative (sequential)

Combinational are built exclusively on logical elements;

Accumulators include logic gates and memory gates;

PC nodes include: registers, counters, adders, multiplexers, etc.

3) Devices - consist of several nodes, perform one or a number of similar operations on machine words. Devices include ALU, memory device, control device, memory device, input / output device.

Digital devices - concept and types. Classification and features of the category "Digital devices" 2017, 2018.