The standard name of "mouse" should be "mouse", and its English name is "Mouse". It has a history of 38 years since its emergence. The use of the mouse is to make the operation of the computer easier. Instead of the cumbersome instructions of the keyboard.

Mouse interface type: The mouse can be divided into three types according to the interface type: serial mouse, PS/2 mouse, and bus mouse. The serial mouse communicates with the computer through the serial port. There are two types of connections: 9-pin interface and 25-pin interface. The PS/2 mouse is connected to the computer through a six-pin micro DIN interface. It is very similar to the keyboard interface. Pay attention to the distinction between the bus mouse interface and the bus interface card. .

The working principle of the mouse: The mouse can be divided into a mechanical mouse and an optical mouse according to its working principle. The mechanical mouse is mainly composed of a rolling ball, a roller and a grating signal sensor. , drives the rolling ball to rotate, and the rolling ball drives the roller to rotate. The photoelectric pulse signal generated by the grating signal sensor installed at the end of the roller reflects the displacement changes of the mouse in the vertical and horizontal directions, and is then processed and converted by the computer program. Control the movement of the cursor arrow on the screen. The optical mouse detects the displacement of the mouse, converts the displacement signal into an electrical pulse signal, and then controls the movement of the cursor arrow on the screen through program processing and conversion. The optical mouse uses a photoelectric sensor instead. Rolling ball. This type of sensor requires a special pad with a stripe or dot pattern.

In addition, the mouse can also be divided into two-button mouse, three-button mouse, and roller mouse according to its shape. The functions of the left and right buttons of a sensor mouse, a two-button mouse and a three-button mouse are exactly the same. Under normal circumstances, we do not need the middle button of a three-button mouse, but when using some special software (such as AutoCAD, etc.), this button will Play some roles; roller mice and sensor mice are commonly used on laptop computers. Turn the small ball in the middle of the mouse in different directions, or move your finger on the sensor pad, and the cursor will move in the corresponding direction. When the cursor reaches the predetermined When you press the mouse or sensor pad, the corresponding function can be performed.

Wireless mouse and 3D mouse: The new wireless mouse and 3D vibrating mouse are relatively new mice. The so-called "wireless" means that there is no wire connection, but a wireless remote control using two AA batteries. The mouse has an automatic sleep function, the battery can be used for one year, and the receiving range of the 3D vibration mouse is within 1.8 meters. It is a new type of mouse that can not only be used as an ordinary mouse, but also has the following characteristics: (1) It has all-round three-dimensional control capabilities. It has six movements: forward, backward, left, right, up and down. direction, and can combine the movement directions of front, right, left, etc. (2) The appearance is different from that of ordinary mice. It generally consists of a fan-shaped base and a movable controller. (3) It has a vibration function, that is, a tactile feedback function. .When playing some games, you will feel your mouse vibrate when you are hit by an enemy. (4) It is a true three-button mouse. No matter in DOS or Windows environment, the middle button and right button of the mouse are very useful.

Keyboard

The keyboard is the most commonly used and important input device. Through the keyboard, English letters, numbers, punctuation marks, etc. can be input into the computer to issue commands to the computer. Enter data etc.

The keyboards in the PC XT/AT era were mainly 83-key and lasted for a long time, but they have been eliminated with the popularity of window systems in recent years. Instead, 101-key and 104-key keyboards took the mainstream position in the market. Of course, there were also 102-key and 103-key keyboards, but due to poor promotion, they were just a flash in the pan. In the past six months, the 104-key keyboard has been followed by the emerging multimedia keyboard, which adds many commonly used shortcut keys or volume adjustment devices to the traditional keyboard, further simplifying PC operations and making it easier to send and receive emails and open browser software. , start the multimedia player, etc., you only need to press a special button. At the same time, major improvements have been made in the appearance, emphasizing the personalization of the keyboard. At first, this type of keyboard was mostly used on brand-name machines. Brand-name machines such as HP and Lenovo were the first to adopt this type of keyboard, which was widely praised and was once regarded as a feature of brand-name machines. As time goes by, independent products with various shortcut functions gradually appear on the market and are sold separately, with dedicated drivers and setting software, and personalized operations can also be realized on compatible machines.

Conventional keyboards include mechanical keys and capacitive keys. Among industrial computer keyboards, there is also a keyboard with touch membrane keys. Mechanical keyboards are the earliest structures adopted. They generally use a principle similar to that of a metal contact switch to make contacts conduct or disconnect. They have the characteristics of simple process, easy maintenance, average feel, loud noise, and easy wear and tear. Most cheap mechanical keyboards Keyboards use copper sheet springs as elastic materials. Copper sheets are easy to break and lose elasticity. The failure rate increases over time. Now they have been basically eliminated and replaced by capacitive keyboards. It is a keyboard based on capacitive switches. The principle is to change the distance between electrodes by pressing the keys to produce changes in capacitance, temporarily forming conditions that allow the oscillation pulse to pass.

Theoretically, this kind of switch is non-contact, with minimal or even negligible wear rate, and no hidden danger of poor contact. It has low noise, easy to control the feel, and can produce high-quality keyboards, but the process is more mechanical. The structure is complex. There is also a keyboard for industrial computers that uses soft-touch membrane keys in order to be completely sealed, and is only suitable for special occasions.

The appearance of the keyboard is divided into standard keyboard and ergonomic keyboard. The ergonomic keyboard separates the left-hand key area and the right-hand key area specified by the fingering on the standard keyboard to form a certain The angle prevents the operator from consciously clamping his arms and maintains a more natural shape. The keyboard with this design is named Natural Keyboard by Microsoft. It can effectively reduce the left and right hand keys for users who are accustomed to touch typing. Areas of miss rate, such as the letters "G" and "H". Some ergonomic keyboards also intentionally enlarge the area of ??commonly used keys such as the space bar and the Enter key, and add a hand support plate at the lower part of the keyboard to provide a support point for the previously suspended wrists and reduce fatigue caused by long-term suspended wrists. These can be regarded as humanized designs.

Keyboard shell. Currently, the keyboards of desktop PC computers all use movable keyboards. The keyboard serves as an independent input component and has its own shell. The keyboard panel is made of different plastics according to the grade. The bottom of some high-quality keyboards uses thicker steel plates to increase the texture and rigidity of the keyboard. However, this undoubtedly increases the cost, so many cheap keyboards directly use plastic base designs. . In order to adapt to the needs of different users, the bottom of the keyboard is equipped with foldable support legs. Expanding the support legs allows the keyboard to maintain a certain inclination. Different keyboards will provide single-stage, double-stage or even three-stage angle adjustment.

Keyboard interfaces include AT interface, PS/2 interface and the latest USB interface. Most desktop computers now use PS/2 interface, and most motherboards provide PS/2 keyboard interface. Older motherboards often provide AT interfaces, also known as "big ports", which are now uncommon. As USB is a new interface, some companies quickly launched keyboards with USB interfaces. The USB interface is just a selling point and has little effect on improving performance. Users who are willing to try and are not nervous about the USB port can choose it.

Floppy drive

The world's first 5.25-inch floppy drive was developed by Shugart Associates in 1976 for IBM's mainframe. It was later used in IBM's early PCs. In 1980, Sony introduced a 3.5-inch disk. From the early 1990s to the present, 3.5-inch, 1.44MB floppy disks have been used as the standard data transfer method for PCs.

Early computers generally used 5.25-inch floppy drives, and there were two main types of 5.25-inch floppy drives. One is a 5.25-inch double-sided high-density floppy drive (also called a 5.25-inch 1.2M floppy drive), which can read and write 5.25-inch double-sided high-density floppy disks (1.2M), 5.25-inch double-sided low-density floppy disks (360K), and 5.25-inch single-sided low-density floppy disks. Floppy disk (180K). The other is a double-sided low-density floppy drive. The main difference from the former is that it cannot read and write 5.25-inch double-sided high-density floppy disks (1.2M). Later, a 3.5-inch double-sided high-density floppy drive (also called a 3.5-inch 1.44M floppy drive) was produced, which can read and write 3.5-inch double-sided high-density floppy disks (1.44M) and 3.5-inch single-sided high-density floppy disks (720K). For a long time, computers generally came with two floppy drives, a 5.25-inch 1.2M floppy drive and a 3.5-inch 1.44M floppy drive. Nowadays, only a 3.5-inch 1.44M floppy drive is generally equipped.

Ordinary floppy drives are characterized by small capacity and high cost per unit capacity; floppy disks are error-prone and have poor reliability; and are slow. Laptops generally use a built-in 3.55" 1.44MB floppy drive or an external floppy drive.

Optical drive

The optical drive is a common accessory in desktop computers. With the increasing use of multimedia The more widely used, the optical drive has become a standard configuration in many desktop accessories. At present, the optical drive can be divided into CD-ROM drive, DVD drive (DVD-ROM), Combo (COMBO) and recorder.

CD-ROM drive: also known as compact disk read-only memory, is a read-only optical storage medium. It was developed using the CD-DA (Digital Audio) format originally used for audio CDs.

DVD drive: It is an optical drive that can read DVD discs. In addition to being compatible with common formats such as DVD-ROM, DVD-VIDEO, DVD-R, CD-ROM, etc., for CD-R/RW, CD-I, VIDEO-CD, CD-G, etc. must be well supported.

COMBO optical drive: "Combo" optical drive is the common name for COMBO optical drive, and COMBO optical drive is a collection. A multi-functional optical storage product that integrates CD burning, CD-ROM and DVD-ROM.

Writing optical drive: including CD-R, CD-RW and DVD burners, among which DVD burners are also included. Divided into DVD+R, DVD-R, DVD+RW, DVD-RW (W stands for repeatedly writable) and DVD-RAM.

The appearance of a recorder is similar to that of an ordinary optical drive, except that the three speeds of writing, rewriting and reading are usually clearly marked on the front panel.

CD burning speed: CD burning speed refers to the maximum CD-R burning speed supported by the optical storage product. At present, the mainstream built-in CD-RW products in the market can achieve a maximum recording speed of 52 times, and there are also some 40 times and 48 times products. In actual work, the recording speeds of the three are affected by factors such as host performance. Not a huge disparity. 52x speed is basically close to the limit of CD-RW recorders, and it is difficult to improve it. The speeds of external CD-RW burners on the market vary widely, including 8x speed, 24x speed, 40x speed, 48x speed, and 52x speed. Generally, products with compact dimensions and an emphasis on portability generally have faster burning speeds. low level. The relatively bulky external CD-RW recorders basically maintain a high recording speed, even the same as the built-in ones.

DVD burning speed: The highest burning speed that DVD burning machines in the market can currently achieve is 16 times. For 2 to 4 times the burning speed, the data transfer volume per second is 2.76M to 5.52MB. A 4.7GB DVD takes about 15 to 27 minutes; burning at 8x speed only takes 7 to 8 minutes, which is only a little slower than burning a CD-R, but considering the data it burns The recording speed of 8x has reached a very high level. DVD burning speed is the primary factor in purchasing a DVD burner. If you have sufficient funds, try to choose a high-speed DVD burner.

CD reading speed: The maximum CD reading speed refers to the maximum optical drive speed that an optical storage product can achieve when reading a CD-ROM disc. Because it is for CD-ROM discs, the speed is rated as CD-ROM double speed, not DVD-ROM double speed. At present, the maximum CD reading speed that CD-ROM can achieve is 56 times; the DVD-ROM reading speed of CD-ROM is slightly lower, and there are relatively few products that reach 52 times, and most of them are 48 times; COMBO products are basically All reached 52 times speed.

For a 50x speed CD-ROM drive, the theoretical data transfer rate should be: 150×50=7500K bytes/second. In fact, the difference in the speed of the optical drive reading the disk is not very important. This is because it is no longer a laggard in a computer system. Moreover, the current nominal value of high-speed optical drives is only the maximum speed at which the outer ring can be read under ideal circumstances. In practical applications, it is generally 24-speed. Therefore, whether it is a 36-speed, 40-speed or 50-speed optical drive, the subjective feeling is not very different in actual use.

DVD reading speed: Maximum DVD reading speed refers to the maximum optical drive speed that optical storage products can achieve when reading DVD-ROM discs. The speed is defined as DVD-ROM double speed. At present, the maximum DVD reading speed that a DVD-ROM drive can achieve is 16 times; the maximum DVD reading speed that a DVD recorder can achieve is 12 times. I believe that 16 times speed products will be launched soon; currently in the COMBO in the mall The maximum DVD reading speeds supported by the product are mainly 8x speed and 16x speed.

CD rewriting speed: CD rewriting speed refers to the maximum burning speed at which the recorder can erase data and burn new data when burning a CD-RW disc and storing data on the disc. Faster CD-RW recorders can reach 32 times the speed when rewriting CD-RW discs. Although DVD recorders also support writing to CD-RW discs, the general CD rewriting speed is slightly lower than that of CD-RW recorders. , only individual products can achieve 32 times the copy speed. COMBO products also perform well in CD-RW rewriting. The products on the market now can basically reach 24x speed, and some products have also reached 32x speed.

DVD rewriting speed: DVD rewriting speed refers to the maximum recording speed at which a DVD recorder can erase data and burn new data when burning a DVD recording disc of corresponding specifications. When data is stored on the disc, . At present, the maximum DVD copying speed that can be achieved by various formats of DVD recorders is 4 times speed, which is about 5.4MB/s per second.

Monitors

Desktop computers usually use two types of CRT monitors and LCD monitors:

Roughly speaking, CRT monitors are now divided into spherical picture tubes and flat picture tubes. kind. The so-called spherical surface means that the cross-section of the picture tube is a spherical surface. This type of picture tube is curved in both the horizontal and vertical directions. A flat picture tube is completely flat both horizontally and vertically, and the distortion will be smaller than that of a spherical tube. Nowadays, the true spherical tube display has disappeared, replaced by the "flat right-angle" picture tube. The flat right-angle picture tube is not actually a plane in the true sense, but the curvature of the picture tube is smaller than that of the spherical tube, which is close to a plane, and the four The angles are just right angles. Currently, except for flat-panel monitors and LCD monitors, all spherical tube monitors on the market are this kind of spherical tube monitors. Since most of them are relatively cheap, they are widely used in low-end models.

At present, most LCD monitors are TFT-type LCD monitors.

The size of a CRT monitor refers to the diagonal size of the picture tube. The maximum viewing area is the maximum range of graphics that the monitor can display. The size of the picture tube is usually measured by the diagonal length in inches (1 inch = 2.54cm). Common ones are 15 inches, 17 inches, 19 inches, 20 inches, etc. The display area will be smaller than the size of the display tube. The display area is expressed as the product of length and height. Usually people also use the diagonal length of the visible part of the screen to express it. The viewing area of ??a 15-inch monitor is about 13.8 inches, the viewing area of ??a 17-inch monitor is mostly between 15 and 16 inches, and the viewing area of ??a 19-inch monitor reaches about 18 inches.

The size of the LCD monitor refers to the diagonal size of the LCD panel in inches (1 inch = 2.54cm). The current mainstream ones are 15 inches, 17 inches, 19 inches, etc.

Fan

Fan noise is the noise generated by the fan when it is working. It is affected by many factors and the unit is decibel (dB). When measuring the noise of the fan, it needs to be carried out in an anechoic room with a noise less than 17dB, one meter away from the fan, and aligned with the air inlet of the fan along the direction of the fan shaft, and measured using A-weighted method.

The spectral characteristics of fan noise are also very important, so a spectrum analyzer is also needed to record the frequency distribution of the fan noise. Generally, the fan noise is required to be as small as possible and there should be no abnormal sounds.

Fan speed refers to the number of times the fan blade rotates per minute, and the unit is rpm. The fan speed is determined by the number of turns of the coil in the motor, the operating voltage, the number of fan blades, the inclination angle, the height, the diameter and the bearing system. When the fan structure is fixed, the rotation speed of the DC fan (that is, the fan using DC power) changes synchronously with the change of the operating voltage. The fan's speed can be measured through the internal speed signal, or it can be measured externally (external measurement uses other instruments to see how fast the fan rotates, while internal measurement can be viewed directly in the BIOS or through software. Internal The measurement error is relatively large).

There is no necessary relationship between fan speed and heat dissipation capacity. Higher fan speed will bring higher noise. When purchasing radiator products, if the air volume is about the same, you can choose a fan with a low speed. It will be quieter when in use.

Air volume refers to the total volume of air sent out or inhaled by the air-cooled radiator fan per minute. If calculated in cubic feet, the unit is CFM; if calculated in cubic meters, it is CMM. Radiator products often The air volume unit used is CFM.

Motherboard

The common motherboard is the ATX motherboard. It is manufactured using a printed circuit board (PCB). It is manufactured using an electronic printing process on an insulating material. There are two main types of boards on the market: 4-layer boards and 6-layer boards. The most common ones are 4-layer boards. The motherboard designed with 6-layer PCB board is not easy to deform and the stability is greatly improved.

The parts on the motherboard look dazzling, but they are all arranged in a very orderly manner. It mainly includes a CPU socket; three major chips such as Northbridge chip, Southbridge chip, and BIOS chip; five major buses including front-end system bus FSB, memory bus, graphics bus AGP, data exchange bus HUB, and peripheral bus PCI; floppy drive interface FDD, universal There are seven major interfaces including serial device interface USB and integrated drive electronic device interface IDE.

1. The main chips on the motherboard

1. Northbridge chip MCH On the left side of the CPU socket is a memory control chip, also called the Northbridge chip. Generally, there is an aluminum heat sink on it. piece. The main functions of the Northbridge chip are data transmission and signal control. On the one hand, it exchanges signals with the CPU through the front-side bus, and on the other hand, it exchanges signals with the memory, AGP, and South Bridge.

2. Southbridge chip ICH4 Southbridge chip is mainly responsible for data processing and transmission of external devices. There are ICH1, ICH2, and ICH3 earlier than ICH4, but they do not support USB2.0. And ICH4 supports USB2.0. It is also very simple to distinguish them: there are 82801AB 82801BB 82801CB 82801DB on the Southbridge chip, which correspond to ICH1 ICH2 ICH3 ICH4 respectively. The most common symptoms after the Southbridge chip is broken are that it does not light up and some peripheral devices cannot be used, such as the IDE port and FDD port. It may also be that the Southbridge is broken. Because the north and south bridge chips are more expensive and the welding is special, removing them requires a special BGA instrument, so general repair points cannot repair the north and south bridges.

3. BIOS chip FWH It solidifies some direct hardware information in a read-only memory. It is the important interface between software and hardware. When the system starts, it first calls some hardware information from it. Its performance directly affects the compatibility of system software and hardware. For example, some early motherboards do not support hard drives larger than 20G, which can be solved by upgrading the BIOS. Some incompatibility problems with new devices that we encounter in daily use can also be solved by upgrading.

If your motherboard suddenly stops lighting up, but the CPU fan is still spinning, you should first consider whether the BIOS chip is damaged.

4. The system clock generator CLK has a crystal oscillator component in the middle of the motherboard. It generates a series of high-frequency pulse waves. These original pulse waves are then input into the clock generator chip and undergo shaping. With frequency division, it is then assigned to the various frequencies that the computer needs.

5. Super input and output interface chip I/O It is generally located at the lower left or upper left of the motherboard. The main chips include Winbond and ITE. It is responsible for converting the serial data coming in from the keyboard, mouse, and serial port into Parallel data. At the same time, the data from the parallel port and floppy drive port are also processed. At our maintenance site, some peripherals such as keyboard and mouse ports, printing ports, etc. cannot be used. Most of them are due to bad I/O chips, which sometimes even cause the lights to not light up.

6. Sound card chip Because most of the current motherboards have integrated sound cards, and most of them are AC’97 sound card chips. Of course, there are also CMI's 8738 sound card chips, etc. If your integrated sound card has no sound, it's most likely broken here.

2. Main sockets on the motherboard

1. CPU socket At present, all motherboards use socket series zero-pull-out sockets. The early P3 used the socket 370 socket, and now the P4 mostly uses the socket 478 socket. The early P4 also used the socket 423 socket. Intel's server CPUs such as Xeon use the socket 603 socket.

2. Memory bus socket There are three types of memory we can see on the market: SDRAM, DDR SDRAM, and RAMBUS. SDRAM memory has gradually faded out of the market due to the price reduction of DDR memory. It uses a 168-wire socket with two anti-reverse insertion breaks in the middle and left; DDR SDRAM has become the mainstream of the market due to its very high cost performance. It uses a 184-wire socket, with only an anti-reverse insertion break in the middle; although RAMBUS memory has good performance, its price has always been high, and Intel has given up its support, so its future is still a matter of suspense! Its socket uses a 184-wire RIMM socket with two anti-reverse plug-in breaks in the middle.

Some customers have repeatedly reported that the 845 motherboard sometimes fails to recognize all the memory. This is because the Iintel 845 series motherboard can only support 4 banks (one bank can be understood as one side of the memory stick). In the 845 Series motherboards generally have three memory slots, and the second slot and the third slot share two banks. Therefore, if the memory modules you insert in the second and third slots are double-sided 256M, then only one 256M will be recognized.

3. AGP graphics bus socket It is located on the left side of the CPU socket and is brown. Its frequency is 64MHZ. In terms of speed, it is divided into AGP2X, most of them are AGP4X now, and some motherboards already support AGP8X. Since different speeds require different voltages, the main reason why some motherboards do not light up is because the user plugs the old AGP2X graphics card into the new AGP2X motherboard, thereby burning out the AGP socket! What is gratifying is that some new motherboards have integrated voltage automatic adjustment devices on the motherboard, which can automatically identify the voltage of the graphics card.

4. PCI bus socket It is white, next to the AGP socket, the number varies depending on the motherboard. Its frequency is 33MHZ. Plug in more network cards, sound cards and other peripherals.

5. IDE device interface It is generally located under the motherboard. There are forty stitches and eighty threads. Two IDE ports are connected together, and sometimes one is green, indicating that it is IDE1. Because the system detects IDE1 first, IDE1 should be connected to the system boot hard disk. Most current motherboards already support ATA100, and some support ATA133, but higher-end motherboards already support Serial ATA. It is a new technology with higher transmission speed that emerged when the parallel transmission rate cannot be further improved. , will also be the next generation of mainstream technology.

Graphics card

The full name of graphics card is monitor adapter card. Today's graphics cards are all 3D graphics accelerator cards. It is an interface card that connects the host computer and the monitor. Its function is to convert the output information of the host into information such as characters, graphics, and colors, and transmit it to the monitor for display. The graphics card is inserted into the ISA, PCI, and AGP expansion slots of the motherboard. ISA graphics cards have been basically eliminated. Nowadays, there are also some motherboards with integrated graphics cards.

Power supply

What is the most important component in a computer? I believe that the answer given by most people is either CPU or graphics card. That's right, almost all the performance of a computer is limited by the performance of these two main components. Next, after everyone is satisfied with the performance of their respective computers, the issue they are more concerned about is stability.

When our computer fails, most users may immediately target "common things" such as CPU, graphics card, motherboard, memory, hard disk, etc., because after all, the performance of the computer is determined by them. If the performance cannot be achieved, of course the first thing to consider is these important performance components. But you have never thought that all high-performance computer components actually have the most primitive essence, that is, they are "electrical" sub-components. Without "electricity", they cannot play any role at all. Therefore, when computers appeared, When a fault occurs, the least concern is the quality of the power supply.

Essentially, the power supply is the most important component of the computer, its heart. If the power supply is abnormal, it is impossible to ensure the normal operation of other parts, and there is no way to check for other faults. According to statistics, power supply failures account for the highest proportion of the entire machine, and many failures are often caused by the power supply. Therefore, the most basic and important maintenance method for computers is to first equip it with a power supply of sufficient power, fine workmanship, and high quality.

Now is the P4 era, motherboards have gradually ushered in the climax of 64-bit, and the world of graphics cards is full of high-end concepts such as NV40 and ! As an advocate of real-standard power in the power supply market, Xingu Power has consistently conveyed the concept of "real-standard power" in this revolution to promote real-standard power, and is dedicated to providing consumers with high-quality power supplies with real-standard power.

Memory

What is memory? In the structure of a computer, there is a very important part, which is memory. Memory is a component used to store programs and data. For computers, only with memory can they have memory functions and ensure normal operation. There are many types of memory, which can be divided into main memory and auxiliary memory according to their uses. Main memory is also called internal memory (referred to as memory), and auxiliary memory is also called external memory (referred to as external memory). External storage is usually magnetic media or optical disks, such as hard disks, floppy disks, tapes, CDs, etc., which can store information for a long time and does not rely on electricity to store information. However, it is driven by mechanical parts and is much slower than the CPU. Memory refers to the storage component on the motherboard. It is a component that the CPU communicates directly with and uses to store data. It stores the data and programs currently being used (i.e., being executed). Its physical essence is one or more groups with An integrated circuit with data input and output and data storage functions. The memory is only used to temporarily store programs and data. Once the power is turned off or a power outage occurs, the programs and data in it will be lost.

Since memory is used to store data and programs that are currently being used (i.e., being executed), how does it work? The computer memory we usually refer to refers to dynamic memory (i.e. DRAM). The so-called "dynamic" in dynamic memory means that after we write data to DRAM, the data will be lost after a period of time, so it is necessary to An additional circuit performs memory refresh operations. The specific working process is as follows: whether a DRAM memory cell stores 0 or 1 depends on whether the capacitor has charge. The presence of charge represents 1, and the absence of charge represents 0. But over time, the capacitor representing 1 will discharge, and the capacitor representing 0 will absorb charge, which is the reason for data loss; the refresh operation checks the capacitor regularly. If the power is greater than 1/2 of the full power, it is considered to represent 1 , and fully charge the capacitor; if the power is less than 1/2, it is considered to represent 0, and the capacitor is discharged to maintain the continuity of data.

Since the beginning of computers, there has been memory. The development of memory has experienced many technological improvements to this day. From the earliest DRAM to FPMDRAM, EDODRAM, SDRAM, etc., the speed of memory has been improving and its capacity has been increasing. What kind of memory are mainly used in servers today? Currently, IA architecture servers generally use REG?ISTEREDECCSDRAM. In the next issue, we will introduce in detail this new memory technology and the unique technical advantages it brings to servers.

CPU

CPU: Abbreviation of Center Process Unit, translated as central processing unit. Also called a microprocessor. Refers to a large-scale integrated circuit with arithmetic and controller functions. The microprocessor plays the most important role in the microcomputer. It is the heart of the microcomputer and constitutes the control center of the system, coordinating and controlling all components in a unified manner.

CPU generally consists of:

The arithmetic logic unit ALU mainly completes arithmetic operations (+, -, ×, ÷) and various logical operations (AND, OR, NOT, XOR, Shift, comparison) and other operations. ALU is a combinational circuit and does not have the function of registering operands. Therefore, it must have two registers to store operands: temporary register TMP and accumulator AC. The accumulator not only provides operands to ALU but also receives the operation results of ALU.

The register array is actually equivalent to the RAM inside the microprocessor. It includes a general register group and a special register group:

General registers (AX, BX, CX, DX) Used to store data, intermediate results or addresses participating in operations. They can generally be used as two 8-bit registers.

With these general-purpose registers inside the processor, frequent memory accesses can be avoided, the instruction length and instruction execution time can be shortened, the machine's running speed can be improved, and programming can be facilitated.

Special-purpose registers include program counter PC, stack pointer SP and flag register FR. Their functions are fixed and are used to store addresses or address base values.

Timing and control logic are the core components of the microprocessor and are responsible for controlling the entire machine, including fetching instructions from the memory, analyzing instructions (i.e. instruction decoding) to determine the instruction operation and operand address, and fetching Operands, perform operations specified by instructions, and send operation results to memory or I/O ports, etc. It also sends corresponding control signals to other components of the microcomputer to coordinate the internal and external components of the CPU.

Network Card

Network Interface Card (NIC -Network Interface Card) is also called Network Adapter (NIA-Network Interface Adapter), or Network Card for short. It is used to realize the physical connection between networked computers and network cables, provides a physical channel for computers to communicate with each other, and carries out high-speed data transmission through this channel. In a local area network, each networked computer needs to install one or more network cards, and the computer is connected to the network cable system through a media connector.

The network card completes most of the functions of the physical layer and data link layer, including the physical connection between the network card and the network cable, media access control (such as: CSMA/CD), disassembly and assembly of data frames, frame sending and receiving, error checking, Encoding/decoding of data signals (such as Manchester code conversion), serial and parallel conversion of data, etc.