Every day, sitting down at his workplace in the office, a person takes a mouse in one hand and begins to fulfill his duties. He knows why he needs a keyboard, printer, scanner, but does not even imagine that they have their official name. All these are input and output devices.
How it works
All devices in a personal computer are controlled by a central processor. To ensure interaction with it, the output and input devices make requests to the south bridge - the logical element of the motherboard. It serves to provide communication and processing requests from external devices to the north bridge or central processor, if the bridge is absent.
In general, computer science is engaged in the study of the structure of a personal computer. It defines input and output devices as components of a typical personal computer that provide the user with a computer. But before starting to describe all the devices, the basic input-output device deserves special mention. It is - BIOS. This chip on the PC motherboard provides an initial check of all connected devices and starts the operating system.
Classification
Personal computer input and output devices can be classified in different ways. The determining factor for this will be their functional responsibilities.
The first paragraph will indicate the main input-output devices. In fact, only one point could be indicated here - the keyboard, since without it, no user computer would continue to boot. You can completely turn off the monitor and mouse, but the computer will not work without a keyboard. The exception is server computers that operate without any external devices connected at all. So, the main input / output devices, without which an ordinary user cannot work, are:
You can also highlight additional input / output devices:
- printers
- scanners
- joystick;
- projector;
- also I / O devices include audio devices.
This is not a complete list of possible devices that interact with the user, you can list them for a very long time. Therefore, let's look at the input / output devices of the computer in more detail.
Monitors
Computer monitors have undergone many changes throughout their history. Starting from the old, using a cathode ray tube, and ending with the modern LCD.
By itself, a monitor or display is a device that serves to display graphic information to the end user. They can be divided according to several criteria.
1. By type of information.
- Alphanumeric These displays are intended solely for displaying textual information.
- Graphic. We encounter these monitors every day, sitting down at a personal computer. They are intended to represent information in graphical form, including video.
2. By screen type.
- CRT A cathode ray tube monitor , with which you may have worked in 2000.
- LCD is a liquid crystal "flat" display, used now everywhere. Also, this type of monitor is used in laptops.
- Plasma
- Laser - has not yet entered mass production.
Keyboards
What about keyboards? The fantasy of manufacturers in this area has stepped far forward, and a sense of humor pushes for the most daring experiments.
Among the keyboards, you can also find minimalistic options - without a side additional panel with numbers, and huge gaming keyboards with built-in joysticks, additional buttons and speakers. There are keyboards with an additional USB-connector and pink keyboards with "obscure buttons" for "blondes". There are also silicone, folding keyboards to make them easier to carry, or just folding three times.
If you are going to get a keyboard, just go to the computer store and choose the one that you like.
Mouse
Computer mice are computer input / output devices without which a normal user cannot work. If an advanced user can navigate through folders and files, as well as some programs and games exclusively using the keyboard, then an ordinary person is simply not able to do this. For all the time of existence, computer mice have undergone not so strong changes.
The first mice worked on the basis of the ball at the base. Moving it in different directions, the ball rotated and controlled the controllers.
Then he was replaced by optical mice based on LEDs. The first generation of optical mice required the obligatory presence of a special rug, on which hatching was applied, contributing to increased reflectivity of the surface. Moreover, the first mice had personal rugs, they could not be replaced with others.
The second generation of optical mice has a more complex device. A mini-video camera is installed on the bottom of the mouse, continuously making micrographs of the surface and comparing them with each other to determine the displacement of the device.
A newer device is a semiconductor laser mouse. Among their advantages can be identified low power consumption, reliability, lack of glow.
Another mouse option is found as an addition to a graphics tablet. Such induction mice are rather inconvenient to use, since they cannot be replaced by more convenient ones on the arm, and increased accuracy is discredited by a small ability to move away from it at a distance from the tablet.
Printers
These are devices for printing information. For all the time of its existence, printers have not changed much. Technologies are developing, laser printers are replacing inkjet printers, but previous generations continue to live. What is the reason for this? The fact is that different types of printers are suitable for different types of printing. All of them perform one function and are not very different in design. The following printer types are available:
- matrix
- inkjet;
- laser;
- thermal printers.
In the matter of choosing such a device, people usually adhere to personal preferences and habits. However, if you are going to print photos on it, and not just text documents, then the laser is more suitable for you due to the increased print quality.
Scanners
A device for inputting information into a computer. The peculiarity lies in the fact that scanners enter information into a PC exclusively in graphical form. The development of scanners has stalled solely on changing their sizes. At first they became smaller and more compact, and then they were replaced by huge "combines" - output and input devices that combine a photocopier, printer and scanner.
Sound
Each of us loves to watch movies, listen to music at home. Speakers, headphones, audio systems and home cinemas, as well as headsets and microphones - all this relates to audio output and input devices.
There are many different microphones and speakers that differ in the quality of recording audio or playing it, respectively. Probably, any person can determine how good the sound of a speaker is. When choosing an audio system, it is also recommended to be guided by design and power to your taste.
Video
To work with video graphics, special devices for outputting and inputting information are allocated - cameras and projectors.
A projector is a device designed to create an image of an object on a large screen. The following types of projectors are distinguished:
- Dioscopic . The image appears due to the passage of rays of light through a transparent film with a picture.
- Episcopal . Creates an image using projection of reflected rays.
- Epidioscopic creates an image of both transparent and opaque objects on the screen.
- The multimedia projector is directly related to the topic of the article. This device displays graphic information from a computer to a large surface.
As for the cameras, then there is no need to tell anyone. In most cases, the higher the resolution of the shooting camera, the better the finished picture. With the advent of laptops, USB cameras began to be replaced by laptops built into the monitor.
Advice
After reading this article, you found out what output and input devices exist, what types they are divided into and what types are relevant today. If you are going to independently equip your workplace and gaming place, as well as independently choose the devices that you want to have at home at hand, then this article should help you with the choice of gadgets.
When going to a computer store, remember that sellers can offer you something more expensive or already stale, outdated goods. Do not be too lazy to go online before reading a trip and read customer reviews about various models of external devices.
Remember the main rule of the buyer: more expensive does not mean better. In a computer store, buying a printer or a headset, you may well overpay for the brand, and then regret your purchase for a long time.
An example is HP printers. Yes, they are considered one of the best, but replacing a cartridge that has ended or just a small malfunction will fly you a pretty penny solely because of the fame of the manufacturer.
When buying a sound system, do not hesitate to check the sound and performance of the speakers. And if you are going to buy a webcam, then test its image, since the resolution not always stated in the documentation may correspond to the available one.
And the main rule. When buying a product, check with the seller for warranty information. For example, for some devices, services require the box in which the unit was delivered. A striking example is Asus laptops. In most cases, nowhere on the store website is information indicated that manufacturers require a company box when contacting a service center.
Be careful and have a good shopping!