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Keyboard prices
The main division of keyboards is by connection and by case type. Classic wired keyboards can be connected via USB or PS/2. The first option is the most versatile - the vast majority of computers have a USB port. At the same time, for stationary PCs with a separate PS / 2 input, it makes sense to purchase a keyboard for it - this will free up an additional USB port for other peripherals.
Wireless connection can be via radio or Bluetooth. The first option is suitable for any device with a USB port - such keyboards are equipped with an appropriate adapter. The second is optimal for portable equipment equipped with a Bluetooth module, such as laptops and tablets: in this case, an adapter is not required at all.
Keyboards can be produced in full-size, compact or Num-case. The first option is designed for cases where the dimensions are not critical - primarily for desktop PCs. Such keyboards have both a basic set of keys and a separate numeric keypad.
Compact models do not have a digital block, which made it possible to reduce the size. They are quite suitable for most tasks, but still less functional than full-size ones. Therefore, it is worth specifically looking for such a keyboard when compactness is crucial - for example, in addition to a travel laptop.
Num-keyboard is actually a separate number pad without other keys. Such models are designed for cases where you need to constantly use the Num-block (for example, for calculations on a calculator), but it is not available in the existing equipment. It can be useful as an addition to a compact keyboard or laptop.
Separately, you can highlight specialized keyboards for tablets. They are made compact, while they can be equipped with special mounts and play the role of a stand. When buying such a keyboard, you need to clarify its compatibility with a specific tablet.
There are gaming keyboards designed for video game fans (including those that are not designed for any other use at all). Another specialization is multimedia: such models have individual keys player controls and can act as a remote control, especially when connected wirelessly. And for those who have to work hard with typing, models of "ergonomic" design can be useful - they reduce fatigue. Also, keyboards with low key travel are considered optimal for fast typing.
Manufacturers even took care of those who like to drink tea or coffee at the computer: keyboards are produced with moisture protection, which tolerate spilling liquid without consequences.
Topic 1.4: Service software and the basics of algorithmization
Introduction to economic informatics
1.2. Technical means of information processing
1.2.3. PC devices and their characteristics
Personal computers are produced in the following designs: stationary (desktop) and portable. The most common are desktop PCs, which allow for easy reconfiguration.
Consider the IBM compatible desktop personal computer. The composition of the PC is called the configuration. Because the modern computers have a block - modular design, the necessary hardware configuration can be implemented from ready-made units and blocks (modules) manufactured by various manufacturers.
Device compatibility is a fundamental principle of the open architecture that IBM has come up with. This was the impetus for mass production of both individual components and computers.
The basic configuration includes devices without which a modern PC cannot work:
- system unit;
- a keyboard that provides information input to a computer;
- mouse manipulator, facilitating the input of information into the computer;
- monitor designed to display text and graphic information.
System unit
In personal computers produced in a portable version, the system unit, monitor and keyboard are combined into one housing.
The system unit is a metal box with a removable lid, which contains various devices computer.
According to the shape of the body are:
- Desktop - flat cases (horizontal arrangement), they are usually placed on a table and used as a monitor stand
- Tower - elongated in the form of towers (vertical arrangement), usually located on the floor.
Cases vary in size, the indicated prefixes Super, Big, Midi, Micro, Tiny, Flex, Mini, Slim indicate the dimensions of the cases. On the front wall of the case there are buttons “Power” - Start, “Reset” - Restart, indicators of power and progress of the PC.
Ports (input - output channels)
The following ports are located on the back wall of the case of modern PCs (more precisely, they can be placed):
- Game - for gaming devices (to connect a joystick).
- VGA - integrated into the motherboard VGA - controller for connecting a monitor for an office or business PC.
- COM - asynchronous serial (denoted COM1-COMZ). A mouse, modem, etc. are usually connected through them.
- PS/2 - asynchronous serial ports for connecting a keyboard and mouse.
- LPT - parallel (designated LPT1-LPT4), printers are usually connected to them.
- USB - a universal interface for connecting 127 devices (this interface can be located on the front or side wall of the case).
- IEEE-1394 (FireWire) - interface for transferring large amounts of video information in real time (for connecting digital cameras, external hard drives, scanners and other high-speed equipment). The FireWire interface is equipped with all camcorders operating in digital format. It can also be used to create local networks.
- iRDA - infrared ports are designed for wireless connection pocket or notepad PCs or cell phone to a desktop computer. Communication is provided under the condition of direct visibility, the data transfer range is not more than 1 m. If the PC does not have a built-in iRDA adapter, then it can be made as an additional external device(USB iRDA adapter) connected via USB port.
- Bluetooth ("bluetooth") is a high-speed microwave standard that allows you to transfer data over distances up to 10 meters. If there is no built-in Bluetooth adapter, then it can be made as an additional external device ( usb bluetooth adapter) connected via the USB port. USB bluetooth adapters are designed to wirelessly connect pocket or notebook PCs, or a cell phone to a desktop computer.
- Connectors sound card: for connecting speakers, microphone and line output.
It should be noted that the presence or absence of the listed ports in a PC depends on its cost and the level of modernity.
AT system unit the main nodes of the computer are located:
- a system or motherboard (motherboard) on which daughter boards (device controllers, adapters or cards) and other electronic devices are installed;
- power supply that converts mains power into D.C. low voltage, for electronic circuits computer;
- a hard disk drive designed to be read from and written to a non-removable hard disk magnetic disk(Winchester);
- optical disc drives (such as DVD - RW or CD - RW) designed to read and write to compact discs;
- floppy disk drives (or drives) used to read and write to floppy disks;
- cooling devices.
Keyboard
Keyboard- a device designed for user input of information into a computer. The standard keyboard has over 100 keys. Keyboard keys are divided into 6 groups:
- Typewriter keys.
- Numeric keys (switching the operating mode is carried out by the NumLock key).
- Editing keys (Insert, Delete, Back Space).
- Cursor keys (two groups of keys: four arrow keys and four keys: Home, End, Page Up, Page Down).
- Special keys (Ctrl, Alt, Esc, Num Lock, Scroll Lock, Print Screen, Pause).
- Function keys F1 - F12 (located at the top of the keyboard and are designed to call the most frequently used commands).
The placement of the keys of the first group corresponds to a typewriter. The arrangement of Latin letters on the IBM PC keyboard is usually the same as on an English typewriter, and the Cyrillic letters are like on a Russian typewriter.
To enter capital letters and other characters located on the upper case of the keyboard, there is a key. For example, to enter an uppercase letter, you must press the key and, without releasing it, press the key with the desired character.
The key is used to fix the upper case mode. The key is used to create a space between characters. The key when editing text works like a "carriage return" on a typewriter. In addition, pressing this key can mean the end of entering a command or other information and accessing the computer.
Switching the keyboard language (Russian - Ukrainian - English) can be done using the keyboard switch located on the taskbar, or using keyboard shortcuts (Shift + Ctrl or Shift + Alt).
Mouse manipulator
Mouse manipulator- manipulator type control device. A small box with keys (1, 2 or 3 keys). Move mouse over flat surface(for example, a rug) is synchronized with the movement of the mouse pointer on the monitor screen.
Information is entered by moving the cursor to a certain area of the screen and briefly pressing the buttons of the manipulator or clicking (single or double). According to the principle of operation, manipulators are divided into mechanical, optomechanical and optical.
Notebook PCs use trackballs and pointers as mice. The combination of a monitor and a mouse provides an interactive mode of operation of the user with a computer, this is the most convenient and modern type of user interface.
Microsoft has released a new set of keyboard and mouse designed for desktop PCs. The product is called Natural Ergonomic Desktop 7000 and uses wireless technology.
Monitors
Monitors are devices that serve to provide an interactive mode of the user's work with a computer by displaying graphic and symbolic information on the screen. In graphics mode, the screen consists of dots (pixels from the English pixel - picture element, picture element), obtained by dividing the screen into columns and rows.
The number of pixels on the screen is called the resolution of the monitor in this mode. Currently, PC monitors can operate in the following modes: 480x640, 600x800, 768x1024, 864x1152, 1024x1280 (number of vertical and horizontal pixels).
Resolution depends on the type of monitor and video adapter. Each pixel can be colored in one of the possible colors. Color display standards: 16, 256, 64K, 16M color shades of each pixel.
According to the principle of operation, all modern monitors divided into:
- Monitors based on cathode ray tube (CRT).
- Liquid crystal displays (LCD).
- plasma monitors.
The most common monitors are cathode ray tubes, but monitors with liquid crystal displays (screens) are becoming more popular. Modern plasma displays have the highest image quality.
Standard monitors come in 14", 15", 17", 19", 20", 21" and 22" diagonal lengths. In CRT monitors, the image is formed by a cathode ray tube. When setting up the monitor, it is necessary to set the resolution and color display mode so that the frame refresh rate does not exceed 85 Hz.
In LCD monitors, the image is formed using a matrix of pixels. Each pixel is formed by the glow of one screen element, so each monitor has its own maximum physical resolution. So, for example, for 19-inch monitors, the resolution is 1280x1024.
In order to avoid distortion of images on the screen, it is recommended to use LCD monitors in their maximum resolution modes. For LCD monitors, the frame rate is not critical. The image looks stable (no visible flicker) even at 60Hz refresh rate.
In plasma monitors, the image is formed using a matrix of pixels, as in LCD monitors. The principle of operation of a plasma panel is a controlled cold discharge of a rarefied gas (xenon or neon) in an ionized state (cold plasma).
A pixel forms a group of three subpixels responsible for the three primary colors, which are microchambers, on the walls of which there is a fluorescent substance of one of the primary colors. This is one of the most promising flat panel display technologies.
The advantages of plasma monitors are that they do not have image flicker, the picture has high contrast and clarity throughout the display, they have good visibility from any angle and a small panel thickness. The disadvantages include - a large power consumption.
The computers we are used to look the same: large case, monitor, keyboard and mouse. All these components take up quite a lot of space, are not very mobile and consume a lot of energy. The Hong Kong company Acute angle decided to change this stereotype. Its engineers separated all the key computer modules from the case and placed them inside a compact keyboard that you can take with you anywhere.
The resulting K2 minicomputer includes a motherboard PCB, Intel processor, video core, up to 8 GB random access memory, a hard drive with a capacity of up to 128 GB and many necessary ports. At the same time, the most advanced (and heavy) model weighs only 450 grams.
In addition to being extremely compact and portable, the keyboard computer offers users incredibly low power consumption. For example, the K2 model consumes only 10 watts of electricity versus 60-80 for an average desktop computer. Thanks to this, all Acute angle models practically do not need and can be assembled without a single cooler.
K2 supports Windows 10 Home OS. The capabilities of even basic models of minicomputers will be enough for most everyday tasks. Among them: creating presentations, working with email and office suites, games, online shopping, music and video.
A few days ago, Acute angle launched a Kickstarter fundraiser and raised the required amount of HK$100,000 almost instantly. Thanks to this, the first K2 will go to their owners in October this year. Their price will be about 14,000 rubles with worldwide delivery.
Personal Computer is a complex electronic device designed to perform a wide range of tasks. It can be various calculations, calculations, listening to music, watching videos, various office tasks, games and much more.
Personal Computer may be stationary or mobile. To mobile computers include laptops, netbooks and tablets.
The desktop computer has also recently undergone changes, but in most cases it is a system unit, monitor, input devices (keyboard and mouse), audio devices (speakers, headphones and microphone), as well as other peripheral devices (printer, scanner, etc.). .).
For normal operation personal computer All you need is a system unit, monitor, keyboard and mouse.
It is also necessary operating system, in most cases they use Windows, but you can also download Linux.
Next, we will take a closer look at each of these devices.
System unit
Main node personal computer is the system unit. He is frame, most often a metal vertical box, on the front panel of which there are power buttons and disk drives. All the necessary connectors and cables are displayed on the back wall. The system unit consists of a power supply, a motherboard (it is also a system board or "motherboard"), hard drive(HDD), video card, processor (CPU), random access memory (RAM), disk drives (CD / DVD), sound card and network card. Often network and sound card are carried out integrated into the motherboard, that is, the radio elements of the board are soldered directly to motherboard.
Power Supply
The power supply is made in the form of a separate box, which is located at the top rear of the system unit and has several power cables for all elements of the system unit.
Power Supply
Motherboard
The motherboard is the largest printed circuit board in the system unit, on which all the main components of the computer (CPU, RAM, video card) are installed, it also has connectors for connecting a hard drive and disk drives, as well as USB ports and connectors that go to back panel corps. The motherboard coordinates the operation of all computer devices.
Motherboard
CPU
The processor is a microcircuit designed to perform basic computing operations. Processors are produced by two companies AMD and Intel. Depending on the manufacturer of the processor, the socket (its installation location) is also different, so you should not forget this when choosing a motherboard. You just don't paste AMD processor on the motherboard for Intel processors.
CPU
video card
The video card is a separate printed circuit board installed in the PCI Express slot of the motherboard and is designed to display images on the monitor screen. It processes the received information and converts it into an analog and digital video signal, which is fed to the monitor through a connector via a cable. A video card usually has a processor (GPU) and RAM.
video card
RAM
RAM is one or more small cards installed in special slots on the motherboard (DDR). RAM provides temporary storage of intermediate data during computer operation. RAM is characterized by the speed of access and the amount of memory. To date, the most fast memory has DDR3 standard.
RAM
HDD
The hard drive is a permanent storage of data, it can be both user data and system or temporary data. The operating system is stored on the hard disk, without which the normal operation of the computer will be impossible. Also, the operating system can use HDD to save the contents of RAM (for example, in hibernation mode). It is a closed metal parallelepiped hard drive, which is connected to the motherboard via a connector (SATA).
HDD
Drive
The optical disc drive looks like a hard drive, but has a retractable optical disc tray on the front panel. Serves as a drive for reading and writing optical discs.
On system board others can be installed additional devices, for example wifi module or TV tuner.
Monitor
The computer monitor is used to graphic representation information that is clearly understandable to the PC user. Recently, only liquid crystal displays (LCDs) have been produced. Monitors can be equipped with digital and/or analog video connectors (DVI, HDMI).
Keyboard
The keyboard is an essential input device for any computer. The keyboard is a group of keys for entering symbolic information. Also, many modern keyboards are equipped with additional keys, for example, to control media players and various programs.
