The hardware of a computer refers to the physical devices that make up the computer, which are divided into five major parts: operators, controllers, memory, input devices, and output devices.
I. The basic hardware components of a computer.
The mainframe is the main body of the entire computer, it can be said that when working with computers, the work is done inside it. The appearance of the host is divided into two kinds of vertical and horizontal. Vertical chassis structure is more conducive to heat dissipation, more popular some.
The keyboard is an indispensable input device in a computer, through which users can enter commands and data, and through which they can control the operation of the computer. Most common keyboards are 101 or 104 keys, and some of the more innovative 104 keyboards tend to come with two Windows keys and an application key to improve the efficiency of operating the computer on the Win7 operating system. These keys can be categorized into a large keyboard area, an edit key area, a function key area, and a small keyboard area.
The large keyboard area*** has sixty-one keys, which are arranged in the same layout as a typewriter and contain 26 letters, 10 numbers, common punctuation marks, space bar, and individual computer-specific keys for typing text, numbers, symbols, and issuing various commands to the computer.
Function key area in the upper left of the keyboard, *** there are twelve keys, the keys are labeled F1 to F12, the role and function with the operating system, application software definition, press F1 can open the application help.
Editing key area on the keyboard on the right side of the middle zone, *** there are ten keys, used in text editing, control of the cursor page, move, and text insertion and deletion and so on.
The keypad area is the seventeen keys on the far right side of the keyboard, including numbers, decimal points, and the four operation symbols.
There are three more keys to the right of the top left function key: the screen print key, the scroll lock key, and the pause key.
The keyboard has three types of interfaces: AT, PS/2, and USB, which can be connected to the corresponding interfaces on the motherboard. When connecting, you just need to correspond to the shape and color of the interface, which is usually not connected incorrectly.
Currently there are many keyboards designed with ergonomics in mind.
The monitor is the basic output device of the computer, and is an indispensable part of the whole computer hardware system.
We now commonly use liquid crystal displays, compared with the traditional cathode ray tube monitors, radiation is relatively low, small size, less power consumption. It utilizes the properties of liquid crystals, the arrangement becomes orderly when energized so that light passes through easily, and the arrangement is chaotic when not energized, preventing light from passing through, and is controlled by a circuit to display images. It has the following parameters:
Screen size: refers to the size of the screen itself.
Viewing angle: the angle between the normal line of the screen and the location where the user can see what is displayed on the screen. The viewing angle of an LCD monitor is symmetrical from left to right, and asymmetrical from top to bottom.
Resolution: the number of pixels that the monitor can display, is the product of the number of dots per line and the number of lines per screen.
Dot Pitch: The distance between two neighboring pixels of a monitor. The smaller the dot pitch, the clearer the monitor picture.
Response time: the speed at which each pixel of an LCD monitor responds to an input signal, i.e., the speed at which a pixel goes from dark to light or from light to dark.
The mouse is an important input device in the computer, which can conveniently position the mouse pointer exactly at the screen position we specified, and easily complete various operations.
According to its working principle, the mouse is divided into mechanical mouse, photoelectric mouse and optical mouse. Currently we often use the mouse is photoelectric mouse. Photoelectric mouse is placed below the two parallel to the small light source, the mouse can only move in a specific mouse pad, the light source issued by the mouse pad after reflection by the mouse to receive the mobile signal, sent to the computer, so that the mouse pointer on the screen and then move. Mouse pointer and mouse movement direction is the same, the movement distance is also proportional. Optical mouse use is more flexible, the failure rate is relatively low.
The mouse generally has two buttons, left and right, the left button is most commonly used, followed by the right button, between the two buttons there is a sliding scroll wheel, mainly to facilitate browsing the web. The mouse is connected to the serial port of the host computer, and the mouse driver is loaded in order to use it. However, for the mouse compatible with Microsoft, the mouse driver compatible with Microsoft has been installed automatically during Win7 installation, so there is no need to install the mouse driver in Win7 environment. According to the different types of interfaces, mice are categorized as serial mice, PS/2 mice, bus mice, and USB mice.
The main performance indicator of a mouse is the resolution, i.e. the number of dots that can be detected per inch of movement.
Wireless mouse is in the mouse with a dry battery wireless remote control, with a USB receiver connected via USB, there is an automatic hibernation function, the reception range within ten meters.3D vibration mouse by the fan-shaped base and a controller that can be movable, with a full range of three-dimensional control capabilities, and vibration function.
The speaker is equivalent to the mouth and throat of the computer, with which the computer can produce a pleasant sound. Speaker shell has a wooden and plastic two kinds of, two speakers a left and a right placed on both sides of the computer, and the monitor has a certain distance, in order to get the stereo effect.
The microphone is equivalent to the computer's ears, with which the computer can transmit external sound to the computer, transformed into digital waveforms, input to the document or multimedia image.
Asymmetric digital subscriber line technology is a broadband technology based on telephone lines that divides the user spectrum over a twisted pair of wires into three bands, with low upstream speeds and high downstream speeds (150 times that of previous modems) without being asymmetric.
Asymmetric digital subscriber line is a dedicated Internet access, and can be and ordinary telephone **** stored on a telephone line, Internet access and receive and make calls do not affect each other, do not need to dial.
The telephone line into the home signal is an analog signal, the information handled by the computer is digital, so the computer into the network communication when the analog signal is converted to a digital signal, the digital signal is converted to an analog signal, respectively, called modulation and demodulation. So we have both functions of the hardware device called modem, commonly known as "cat". Asymmetric digital subscriber line modems are divided into three types: built-in, external and USB.
Printers are also a common output device. Because what is displayed on the monitor is invisible once the power is turned off, and it is not convenient to move the monitor around for others to read, we still need to use a printer to print out the results of our work.
Printers are divided into pin printers, inkjet printers and laser printers.
Pin printers print characters and graphics through the needles on the print head, which has a lower resolution and slower printing speed.
Inkjet printers are small in size and mass, print at a resolution of 360 dots per inch or more, and print more slowly with average results.
Laser printers are a combination of copiers, computers and lasers, printing speed, high resolution, no noise, with synchronized multi-side mirrors and complete optical components to write characters on the toner cartridge, the laser sweeps over the toner cartridge by switching the two states to indicate the white area and the black area. The toner cartridge rotates once and the laser printer prints a line. The laser printer itself contains memory, typically between 64MB and 2GB.
The scanner is the main device for text and picture input, equivalent to the eyes of the computer, capable of converting optical signals into electrical signals through optoelectronic devices, and converting the electrical signals into digital signals through analog-to-digital converters to transmit a large amount of textual and pictorial information into the computer.
The key device of the scanner is the charge coupler, which adopts a prismatic color-separation optical system to separate natural light into red, green and blue primary colors to scan graphics.
Flatbed scanner, text and pictures are fixed in a glass window, the scanning head moves under the text or picture, accepts the reflected light from the text or picture, these reflective rays are reflected by a system of mirrors, through the convex lens to focus the light on top of the photodiode, turning the light into an electric current, and then finally converted into digital information to be stored in a computer, which is capable of scanning once and reading in an entire page of It can read a whole page of text or pictures in one scan.
Scanner performance indicators include: optical resolution, color bits, scanning speed and format size. Optical resolution, also called horizontal resolution, is measured in pixels per inch or dots per inch. Color bits are the scanner's ability to distinguish the colors of a picture.
Cameras can be divided into two categories: digital cameras and analog cameras. Digital cameras can capture images directly and transfer them to a computer through a serial, parallel or USB port. According to the form of the camera, it can be divided into desktop pedestal type, high pole type and LCD hanging type. Cameras can also be divided into driven and non-driven type of camera.
The technical specifications of the camera are image resolution/resolution, image format, number of color bits, image compression method, and performance indicators such as video capture rate, horizontal and vertical scanning frequency, maximum moving image resolution, maximum still image resolution, signal-to-noise ratio and automatic brightness adjustment.
Digital camera is a new type of image processing equipment, it works on the same principle as the general camera, is the use of when the object is away from the convex lens is greater than twice the focal length of the convex lens can become an inverted reduced real image of the principle of the outside world to the external image sensitivity to the camera's internal photosensitive chip, after digital processing, directly stored in the camera's memory and can be directly put on the computer. After digital processing, the images are stored directly in the camera's memory and can be put directly into a computer. However, the quality of the photos is slightly inferior to that of traditional photos. The longer the focal length of the lens, the more room for the convex lens and sensor to move, and the greater the zoom power, the farther away the scene can be photographed.
The number of pixels in a digital camera includes effective pixels (the value of the pixels that are actually involved in light-sensitive imaging, converted at the lens zoom magnification) and maximum pixels (the true pixels of the light-sensitive device).
The touch screen of a computer is a novel input device, including surface acoustic wave touch screen, resistive touch screen, capacitive touch screen and infrared touch screen. It has the function of an input device, giving commands directly on the screen with your hand, and cannot be used alone away from the computer screen, and has an output function.
Surface acoustic wave is a kind of mechanical wave that propagates along the surface of the medium. When the finger touches the screen, the sound wave on the contact is blocked to determine the position of the coordinates. The touch screen is made of a flat glass plate, installed in front of the monitor screen, the upper left and lower right corners of the vertical and horizontal direction of the ultrasonic transmitting transducer, the upper right corner of the two corresponding ultrasonic receiving transducer fixed. The four peripheries have reflective stripes sparsely to densely spaced at a 45-degree angle in precise intervals.
Resistive touch screen is a multilayer composite film with the surface of the display, the grass-roots level for a layer of organic or inorganic glass, the surface of a layer of transparent conductive layer, covered with a layer of hardening treatment of the outer surface, smooth and scratch-resistant plastic layer, the inner surface of the inner surface is also a layer of transparent conductive layer, the conductive layer of the conductive layer of the two layers of the transparent isolation between the point of separation between the insulation between them a number of small transparent.
Capacitive touch screen is in the glass screen plated with a transparent thin film body layer, in the conductor layer plus a piece of protective glass, plated on all sides of the narrow electrode, the conductor to form a low-voltage AC electric field.
Infrared touch screen by mounted on the outer frame of the touch screen infrared emission and acceptance of sensing elements, the hand can change the contact on the infrared light, to achieve the touch screen operation.
The operation on the computer is no longer single rely on the keyboard and mouse, the light pen is suitable for habitual writing user's operation, with a full range of mouse functions, and the computer's serial port connected.
The light pen can be operated directly on the computer screen or on a reflective panel. With the light pen, users can enter text in the same way as they are accustomed to writing, without having to master an input method.
Projector is a projector by the convex lens, plane mirror, light screen and other components of the optical instrument, it can be projected on the slide image or text enlarged projected on the screen, is the use of the object away from the convex lens distance is less than twice the focal length is greater than the focal length of the convex lens into an inverted magnification of the principle of the real image, the technical indicators is the brightness of the light is a description of the unit of time the light source radiation produces a strong or weak ability to visually respond to the light source. In the international system of units, it is the unit of lumens.
The projector is connected to the host computer's display card, and the video output is connected to a fifteen-pin D-type interface cable on the monitor to make the monitor work like the original.
Liquid crystal is a substance between liquid and solid matter, the projector uses the photoelectric effect of liquid crystal to produce images with different gray levels, color, divided into liquid crystal light valve projector and liquid crystal panel projector.
Plotter is a device that automatically draws graphics according to people's requirements. It can output the output information of the computer in the form of graphics. Plotter is mainly used to draw a variety of management charts and statistical charts, geodetic maps, architectural design drawings, circuit wiring diagrams, a variety of mechanical drawings and computer-aided design drawings.
Modern plotter has an intelligent function, it has its own processor, you can use the drawing commands, with linear and character algorithm processing and self-testing and other functions. In the drawing software support, the plotter can draw complex and accurate graphics, is a variety of computer-aided design indispensable tool. Plotter performance indicators are mainly the number of drawing strokes, drawing paper size, resolution, interface form and drawing language. There are many types of plotter, according to the structure and working principle, the plotter can be divided into two categories of roller and platform.
Two, the host of the basic hardware components.
Open the main chassis, we can see the host by the power supply, motherboard, central processing unit, memory, hard disk, display card and sound card and other components.
The power supply is generally installed in the host box, its role is to convert the AC 220V voltage for computer components to work ± 5V, ± 12V and other DC voltage. The quality of the power supply is critical to the stability of the computer, because power failures can easily cause the computer to work improperly, and in serious cases even burn the motherboard, the central processing unit and other valuable components.
Power supplies generally come with a fan that blows air outward through a corresponding opening in the chassis, which serves to cool the power supply itself as well as for air circulation and cooling inside the chassis, so it's usually desirable to have a fan with the highest possible airflow and the lowest possible noise level.
We're now using a new power structure called ATX power, which is very powerful, not only with better power management, but also with support for soft shutdowns. With it, after you confirm the shutdown with your mouse, you don't have to press the POWER button on the main chassis with your hand, the computer can already be shut down automatically.
Today's multimedia computers use a 350-watt power supply.
The mainframe of a minicomputer is generally fitted with a system motherboard, the largest printed circuit board installed in the mainframe, on which are distributed the various components and plugs that make up the computer system circuitry.
The motherboard has many large-scale integrated circuits, ultra-large-scale integrated circuit devices and electronic circuits, including chipsets, central processing unit sockets, memory slots, bus expansion slots, peripheral ports and BIOS chips. Many motherboards with power management features, in the specified time, no keyboard, mouse and disk operation, the system automatically cuts off the disk drive and monitor power supply, so that the screen goes black, the system only to the central processor power supply. The bus is a set of wires with a string of plug adapters, all of which are connected to each wire. When a bus adapter is inserted into one of the expansion slots, it is connected to the bus's public **** wire, which receives the public **** signals and information coming from inside the microcomputer.The ISA expansion slot is generally black in color, and is the longest expansion slot in the motherboard, and is one of the must-have slots in the early motherboards.The PCI expansion slots are shorter in length, generally white in color, and the bit widths are generally 32-bit or 64-bit. Currently only graphics cards have an AGP bus.
The parallel communication port, LPT1, is commonly known as the print port because it is often connected to a printer, which transmits eight signals simultaneously and a complete byte of information at a time in parallel.
Serial communication port, that is, COM1, COM2, generally connected to the mouse, external Modem or other serial devices. It can only transmit one signal in one direction, one binary bit at a time, and one byte of information can only be transmitted one byte at a time.
The USB port can be used for USB flash drives, digital cameras, cell phones, and also for printers. Today's printers can be connected directly to a computer through a USB port, and the appropriate printer driver can be installed.
On the motherboard, there is usually a ROM-BIOS, which is a system boot program solidified in read-only memory. It saves the most important basic input and output programs of the computer, system setup information, power-on self-test program and system boot boot boot program. Read-only memory is normally read-only.
The central processor is the heart of the computer, composed of operators and controllers, the internal structure is divided into controllers, operators and memory, these three parts of the coordination of each other, you can make judgments, calculations and and control the computer parts of the coordinated work.
The current popular central processor for the Intel Core central processor, divided into dual-core, quad-core and octa-core. Dual-core CPUs are based on a single semiconductor that has two processor cores with the same functionality on one processor.
Measurement of the central processing unit is the word length, word length is the computer can directly handle the number of bits of binary data, marking the computer's ability to process data, the word length determines the ability of the computer's arithmetic and precision, the longer the word length, the computer's arithmetic ability is stronger, the higher the precision, the more the number of effective data storage units, the stronger the ability to find the address. The word length of personal computers is now divided into sixteen, thirty-two and sixty-four bits.
The memory in which high-speed data exchange can take place is called a cache, also called a cache. The central processor usually reads data from the cache, and the central processor calls for data from the memory only when it has no data. The larger the cache capacity, the better the performance of the central processor. The cache of a CPU is divided into a Level 1 cache and a Level 2 cache. In Core processors, the memory controller and cache for all four cores are on top of a single die.
Memory is the memory component of a computer and is used to store raw data, intermediate results, and programs that instruct the computer to work during operation.
Memory can be divided into random-access memory, which allows data to be read and written, and read-only memory, which allows data to be read and written. Programs on disk must be transferred into memory before they can be run, and the central processor has direct access to memory to exchange data with it. When the computer loses power, the information in the random access memory is lost. The information in the latter can only be read, not randomly written, and is not lost even when the power goes out.
Because of the complexity of the circuitry factor, the computer are used in the binary number, only 0 and 1 two digital, every two into one, the easiest to express with the circuit, such as 0 on behalf of the circuit does not work, 1 on behalf of the circuit is smooth. We usually use the computer does not feel it is in the binary calculation is because the computer will be your input information is automatically converted to binary, calculated binary number and then converted to you can see the information displayed on the screen.
In memory contains a large number of basic units, each storage unit can hold eight binary bits, i.e., an integer between zero and two hundred and fifty-five, a letter or a punctuation mark, etc., called a byte. The capacity of the memory is the basic unit of bytes, each unit has a unique serial number, called the address. By virtue of the address, the central processor manipulates each unit accurately and processes the data. Since the unit of byte is too small, we define several larger units that are rounded to the tenth power of 2, in units such as KB, MB, GB, TB, and so on.
Common types of memory include synchronous dynamic random memory, double-rate synchronous dynamic random memory, and interface dynamic random memory.
External memory is like a diary, used to store some programs or data that need to be stored for a long time, and will not be lost after a power failure, the capacity is relatively large, but the access speed is slow. When the computer wants to execute the program in the external memory and process the data in the external memory, it needs to read the data in the external memory into the memory first, and then the central processor can process it.
The magnetic disk of a hard disk is made of a hard material with a high degree of precision. The hard disk is enclosed in a casing along with the drive, and it has a much larger capacity and is much faster to read and write than a flash drive or CD-ROM.
The hard disk is composed of several hard disk platters around a **** the same axis of the platter group, two platters only leave the distance between the placement of the magnetic head. Each platter has two platters, the platters are divided into a number of concentric circles, known as magnetic tracks. These concentric circles have different perimeters but the same amount of storage. Each track is divided into many areas, each called a sector, and each sector stores five hundred and twelve bytes of information. In a hard disk, a collection of identical track numbers on several platters is called a plenum, and these tracks have an identical direction of rotation of the magnetic field. Each platen corresponds to one head, but with today's hard drives, two heads can read one platter. So the hard disk capacity is determined by the number of plasmas, the number of platters, and the number of sectors per track. Hard disk capacity is equal to the number of cylinders multiplied by the number of platters multiplied by the number of sectors per track multiplied by 512, usually in GB, TB, many hard disk manufacturers calculate GB and TB in decimal, 1GB is 1000MB, 1TB is 1000GB.
The inside of the hard disk consists of magnetic storage platters, the number of which ranges from one piece to three pieces, and each platter has a certain capacity called the single disk Each platter has a certain capacity, called a single disk, and the sum of the capacities of several platters is the total capacity of the hard disk.
The spindle motor of a hard disk drives the platters to rotate at high speed, generating buoyant force that makes the magnetic head float above the platters, and the hard disk reads the data on the platters through the magnetic head, and the faster the rotational speed is, the shorter the data-reading time will be. The faster the RPM, the shorter the time it takes to read the data. The RPM largely determines the speed of the hard disk.
The time it takes for a hard disk's magnetic heads to move to a designated track on the platter is called the average seek time, measured in milliseconds, and the smaller this time is, the better.
The data transfer rate is the rate at which the computer can accurately find the appropriate data from the hard disk and transfer it to the memory, including both internal and external data transfer rates, and is measured in megabytes per unit of time. Hard disks have IDE and SCSI interfaces.
Flash drives are miniature, high-capacity mobile storage products that do not require a drive with a USB interface. Flash chips are used as the storage medium, connected to the computer through the USB interface to realize plug-and-play.
Computer binary digital signals into a composite binary digital signals (joining the allocation, check, stack and other commands) read and write to the USB chip adapter interface, through the chip processing signals assigned to the EEPROM memory chip of the corresponding address of the storage of binary data to achieve the storage of data. eeprom data memory, the principle of its control is a voltage-controlled gate transistors of the high and low values of voltage, the gate transistor junction capacitance, the gate transistor junction capacitance, the gate transistor junction value, the gate transistor junction value is the value of the voltage. The junction capacitance of the gate transistor can save the voltage value for a long time, and the main reason for saving the data after power failure is that the floating gate and the selection gate are added to the original transistor. A floating gate that stores electrons is formed on a semiconductor that conducts current unidirectionally between the source and the drain. The floating gate is wrapped with a silicon oxide film insulator. Above it is a selector/control gate that controls the transfer current between the source and drain. The data is 0 or 1 depending on the presence or absence of electrons in the floating gate formed on the silicon substrate. The presence of electrons is 0 and the absence of electrons is 1. Flash memory, as its name implies, is initialized by deleting data before writing. Specifically, the electrons are exported from all the floating gates. This means that all data will be returned to "1". When writing, only when the data is 0 is written, and when the data is 1, nothing is done. When writing 0, a high voltage is applied to the gate electrode and drain to increase the energy of the electrons conducting between the source and drain. This causes the electrons to break through the oxide film insulator and enter the floating gate. When reading data, a certain voltage is applied to the gate electrode, and a large current is 1, while a small current is set to 0. In the state where the floating gate does not have electrons (data is 1), applying a voltage to the drain electrode when the gate electrode applies a voltage to the state, a current is generated between the source and drain electrodes due to the movement of a large number of electrons. In contrast, in the state where the floating gate has electrons (data of 0), fewer electrons are conducted in the channel. Because the voltage applied to the gate electrode is absorbed by the floating gate electrons, it is difficult to have an effect on the channel.
Superdisks usually have a capacity of 1 GB to 8 GB.
CDVDs have a large capacity of about 700 megabytes to 50 GB, are portable and inexpensive, and have a capacity equal to the sum of the capacity of several hundred floppy disks or flash drives.
The optical disk is divided into five main layers: substrate, recording layer, reflective layer, protective layer and printing layer. The material of the disc is plastic, the data surface is plated with a layer of aluminum, and the data is recorded on concave and convex undulating grooves of different heights, which are read by the laser head of the optical disc drive. The laser from the head hits the bumpy surface and then focuses on the recesses and bumps of the reflective layer. The convex surface reflects the laser light back as it is, and the concave surface diffuses the light. Optical disc drives recognize data based on "reflection" and "dispersion," with light intensity varying from high to low, from low to high as 1, and continuous light intensity for a period of time as 0.
Optical disc drives include read-only drives, burners, DVD drives, and so on, DVD drives, etc. CD-ROM drives are generally built-in with a front panel with a headphone jack, volume control dial, LED indicators, play/skip buttons, and load/exit CD buttons. The basic function of a graphics card is to control the computer's graphics output. It is installed in an expansion slot on the computer's motherboard or integrated into the motherboard and works between the central processor and the monitor.
Display card mainly includes the image processor, video memory, digital-to-analog converter, AGP bus interface and other parts of the data flow from the central processor to the central processor after the data coming from the central processor to the image processor to process the chip processed data into the video memory, read out the data from the video memory to send the digital-to-analog converter to the data conversion work from the digital-to-analog converter into the monitor.
Display
Graphics memory is the core component of the graphics card, storing the data processed by the graphics chip, the larger the memory, the larger the maximum resolution supported by the graphics card. The larger the memory, the larger the maximum resolution supported by the graphics card. The capacity of the memory is at least "horizontal resolution*vertical resolution*log2 colors/8".
The NICs are divided into Ethernet NICs and laptop NICs, and a NIC has an LED indicator to show the different working status of the NIC. Laptop computers are generally equipped with built-in network card and wireless Internet access, available network cable through the laptop RJ-45 interface to connect to the network, wireless Internet access, you need to check the laptop wireless Internet access switch is open.
Now the mainstream network card for the PCI interface card, the theoretical bandwidth is 32-bit 133MB, the current mainstream is 10/100/1000Mbps PCI adaptive card, according to the need to automatically identify the operating frequency of the connected network devices, automatically work in the 10/100/1000Mbps network bandwidth.
Desktop computers have a network card on the motherboard and an RJ45 crystal interface on the back of the host computer, which connects to the network via a network cable.
Sound is an analog signal, and when a computer processes sound, it goes through an analog/digital conversion that turns it into a series of digital quantities called digitization. In a computer, a sound card is necessary to process sound information more perfectly.
A sound card is the basic configuration of a multimedia computer. It has three main functions. Music synthesis pronunciation function, analog audio input and output function, mixing effector function.
In the past, when using a sixteen-bit sound card, the sampling frequency is 44.1 kHz, the sound of one second is cut into 44,100 equal parts, and the sixteen-bit bit length can cut the signal amplitude into 65,536 equal parts. With a bit length of twenty-four bits, the signal amplitude can be sliced into 16777216 equal parts. This is like the measurement of length, where units in feet certainly seem rougher than units in inches. Therefore, at the same sampling frequency, the larger the bit length, the better the result. For the same bit length, the higher the sampling frequency, the better the results.
Video cards are not the same as display cards and include video capture cards, video overlay cards, TV receiver cards, TV encoding cards, DVD playback cards, etc., which are used for video-assisted functions in multimedia computers.
The main function of the video capture card is to digitize the film and television images and send them to the computer for processing. It can play the standard video signal on the computer monitor for video image capture. When the video capture card and the display card are connected, the display content can be adjusted in terms of color and contrast, and special effects and subtitles can be superimposed and other processing.
The video overlay card inputs standard video signals through the video input port, superimposes them on the computer's own VGA signals, and sends the combined processed signals to the monitor.
The TV receiver card receives PAL and NTSC TV signals, allowing you to watch TV in front of your computer screen.
The TV encoding card converts signals from the computer screen to TV signals to watch the picture on the computer screen on the TV. Its output is connected to the video input of a large screen TV.
I hope I can help clear your doubts.