What brands of computer CPUs are there?
The question is: What brands of CPUs are there? Is the processor of a notebook the same as the processor of a desktop? Is the CPU of a mobile phone different from the CPU of a computer? , why the software on mobile phones and computers are not universal is because of the processor.
Answer: There are currently two processor brands for desktop computers and notebooks: Intel and AMD.
The processors of laptops and desktop computers are the same. Due to technical and legal reasons, most of the original computer CPU manufacturers have not joined the ranks of mobile phone and other CPU manufacturers, but there may be in the future.
The CPU directly leads to the data processing method of the program. Therefore, processors with different architectures can only run different systems. Different systems naturally run different programs. Therefore, the reason why the software of mobile phones and computers is not universal is the processor.
What does optical storage mean? Basic computer knowledge
Optical storage is affected by the medium on the surface of the optical disc. There are uneven pits on the optical disc. When the light shines on it, there are different reflections, and then it is converted into digital signals of 0 and 1. optical storage.
Overview of optical storage:
Optical storage refers to technologies, equipment and products that use laser technology to store data on discs, such as optical discs (optical discs), laser drives, related algorithms and Software etc. From the invention of the ruby ??laser in 1960, to the launch of CD discs in 1981, VCDs in 1993, DVDs in 1995, and then BD and HD DVDs in 2002, optical storage technology has been changing with each passing day. The rapid development and widespread use of optical storage technology not only provides conditions for the development and application of computer and multimedia technology, but also changes human entertainment methods to a great extent and greatly improves our quality of life. Of course, there is a protective film on the outside of the disc, which is generally invisible, but you can see where there is information and where there is no information. The same principle applies to recording optical discs. When burning, the light is relatively strong and different concave and convex spots are burned out.
Optical disc is just a general term, which is divided into two categories. One is read-only optical disc, including CD-Audio, CD-Video, CD-ROM, DVD-Audio, DVD-Video, DVD-ROM etc.; the other type is recordable optical discs, which include CD-R, CD-RW, DVD-R, DVD R, DVD RW, DVD-RAM, Double layer DVD R and other types.
With the development of optical technology, laser technology, microelectronics technology, material science, micro-processing technology, computer and automatic control technology, optical storage technology has improved in recording density, capacity, data transfer rate, and addressing time. There will be huge development potential in other key technologies. At the beginning of the next century, optical disk storage will make significant progress in terms of functional diversification and intelligent operation. With the development of optical quantum data storage technology, three-dimensional volume storage technology, near-field optical technology, and optical integration technology, optical storage technology will surely become one of the pillar technologies in the information industry in the next century.
Principles of optical storage
Whether it is a CD disc, DVD disc or other optical storage media, the storage method used is the same as that of a floppy disk or a hard disk, and information is stored in the form of binary data. . To store data on these optical discs, a laser is needed to engrave the binary data converted by the computer on a flat, reflective disc using a data pattern. In order to identify the data, the small pits carved by the laser on the optical disc represent binary "1", while the blank spaces represent binary "0". DVD discs have smaller recording pits than CD-ROMs, and the distance between spiral storage pits is also smaller. The pits in which DVD stores data information are very small and very dense. The minimum pit length is only 0.4μm. The distance between each pit is only 50% of that of CD-ROM, and the track gauge is only 0.74μm.
The main parts of a series of optical storage devices such as CD drives and DVD drives are laser generators and light monitors. The laser generator on the optical drive is actually a laser diode, which can generate a laser beam of corresponding wavelength, and then after a series of processing, it is emitted to the optical disc, and then the reflected signal is captured by the optical detector to identify the actual data. If the disc does not reflect the laser, it means there is a small pit there, and the computer knows that it represents a "1"; if the laser is reflected back, the computer knows that the point is a "0." The computer can then convert these binary codes into the original program. When the optical disc rotates at high speed in the optical drive, the laser head moves back and forth under the control of the motor, and the data is continuously read out.
Understanding computer hardware: What is a computer power supply?
A computer power supply is a device that converts 220V AC power into DC power and specifically supplies power to computer accessories such as motherboards, drives, graphics cards, etc. , is the hub of power supply for various components of the computer and an important part of the computer. At present, most PC power supplies are switching power supplies.
Computer power supply classification
ATX power supply
The ATX specification is a new motherboard structure standard formulated by the Intel Group in 1995. It is in English (AT Extend) The abbreviation can be translated as AT extended standard, and the ATX power supply can be a power supply designed according to this specification. Home computer power supplies currently on the market all follow the ATX specification.
BTX power supply
BTX power supply is a PC power supply designed according to the BTX standard, but the BTX power supply is compatible with ATX technology. Its working principle and internal structure are basically the same, and the output standard is the same as The current ATX12V 2.0 specification is the same and uses a 24pin connector like the ATX12V 2.0 specification. The BTX power supply is mainly derived from the ATX 12V, CFX 12V, and LFX 12V power supply specifications based on the original ATX specification. Among them, ATX 12V is an existing specification. The reason why we continue to look at it is because the ATX12V version 2.0 power supply can be directly used in standard BTX chassis. CFX12V is suitable for chassis with a total system space of 10 to 15 liters. Let's look at the power supply. Although there is no technical change from the previous power supply, it adopts an irregular appearance in order to meet the needs of the size. Currently, three specifications are defined: 220W, 240W, and 275W. The 275W power supply adopts independent dual-channel 12V outputs. The LFX12V is suitable for chassis with a system space of 6 to 9 liters, and currently has two specifications: 180W and 200W. BTX is not an innovative power supply standard. Although the INTEL Group vigorously promotes it, because there are too few manufacturers that support it, it is rarely mentioned now.
Rated power of the power supply
The rated power is the power marked by the power supply manufacturer in accordance with the standards set by the INTEL Group. It can represent the average output of the power supply. The unit is watts, referred to as watts (W). ). The greater the rated power, the more devices the power supply can load.
There are many ways to express the power of a power supply. In addition to rated power and peak power, there is also output power. Output power refers to the power that the power supply can output stably for a long time under necessary conditions. When the power supply actually works, the output power does not have to be equal to the rated power. According to the INTEL Group's standards, the output power will be greater than the rated power, such as about 10. It must be noted that among the various power nominal methods, the rated power is formulated in accordance with the INTEL Group standards and is the most reliable standard for power supply power. It is recommended to use the rated power as a reference and comparison standard when purchasing a power supply. Unfortunately, the names of some power supply manufacturers are not standardized at present, and there is a problem of imaginary numerical values.
At present, the rated power of desktop computer power supply is 200-400W. The specific requirements mainly depend on the needs of computer CPU, graphics card, hard disk and other accessories. The most common requirement is 250-350W. The power supply with higher rated power is better, but of course the price is also more expensive. When purchasing a power supply, you can consider the possibility of not upgrading the hardware and leave a certain amount of margin. However, because the rated power can be a very strict nominal method, too much margin is useless, and there is no need to blindly pursue an excessively high rated power.
Importance of power supply
One of the hard-to-find problems in PC can be insufficient power supply. The symptoms may be that the motherboard is "unusable" and the software causes frequent system crashes. These symptoms may be It is manifested by abnormalities in the motherboard, CPU or memory, and sometimes it seems to be problems with the hard disk, CDROM, floppy disk, etc.
You can imagine: every component in the PC system has the same source of power - the power supply. The power supply must provide stable, continuous current to all equipment without interruption. There may be excessive or insufficient power, and the connected device may not function properly and appear to be broken. For example, the memory cannot be refreshed, causing data files to be lost (leading to software errors); the CPU may deadlock, or restart randomly; the hard disk may not spin, or even weirder---it spins and cannot process controls normally. Signal.
Since so many devices are closely related to power supply, it is no exaggeration to regard the power supply as the most important component of the PC hardware system. Unfortunately, most people fail to realize that when purchasing a power supply, they sometimes prefer old chassis (the chassis has a power supply) in the hope of "cheap and good quality". (As a rule of thumb, this is a common problem.) Older power supplies are no longer as efficient as when they were first used, and do not provide as much energy as the nominal value. Many power supplies do not have the UL mark and may only be able to "extrude" 50-75% of the nominal value. Even the power supply in a well-known chassis may have problems, and we have encountered it in our daily life.
Computer hardware understanding: What is a computer optical drive?
An optical disk drive (optical drive) is a product that combines optical, mechanical and electronic technologies. In terms of combining optics and electronics, the laser light source comes from a laser diode, which can produce a beam with a wavelength of about 0.54-0.68 microns. After processing, the beam is more concentrated and can be precisely controlled. The beam is hit on the optical disc in the first step, and then the optical disc is Reflected back, the signal is captured by a light detector.
There are two states on the optical disc, namely pits and blanks. Their reflected signals are opposite and can be easily identified by a light detector. The information obtained by the detector is only the arrangement of bumps and convex points on the optical disc. There are special components in the drive to convert it and verify it. Then we can get the actual data. The optical disc rotates at high speed in the optical drive, and the laser head moves back and forth under the control of the servo motor to read data.
Classification of optical drives
Optical drives are a very common accessory in desktop computers. As the application of multimedia becomes more and more widespread, optical drives have become standard configuration in many accessories of desktop computers. At present, optical drives can be divided into CD-ROM drives, DVD optical drives (DVD-ROM), COMBO and recorders.
CD-ROM optical 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 optical 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., it is also compatible with CD-R/ RW, CD-I, VIDEO-CD, CD-G, etc. must be supported very, very well.
COMBO optical drive: "Comba" optical drive is the common name for COMBO optical drive.
The COMBO optical drive is a multi-functional optical storage product that integrates CD burning, CD-ROM and DVD-ROM.
Burning optical drives: including CD-R, CD-RW and DVD burners, among which DVD burners are divided into DVD R, DVD-R, DVD RW, DVD-RW (W stands for repeatedly erasable write) 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.
Understanding computer hardware: What is a computer network card?
The connection between the computer and the external LAN is through inserting a network interface board into the host box (or inserting a PCMCIA card into the laptop computer) ). The network interface board is also called a communication adapter or network adapter (adapter) or network interface card NIC (Network Interface Card), but now more people are willing to use the simpler name "network card".
1. Detailed explanation of the function of the network card
The network card is equipped with a processor and memory (including RAM and ROM). Communication between the network card and the LAN is carried out through serial transmission through cables or twisted pairs. The communication between the network card and the computer is carried out in parallel transmission through the I/O bus on the computer motherboard. Therefore, an important function of the network card is to perform serial/parallel conversion. Since the data rate on the network is not the same as the data rate on the computer bus, a memory chip that caches the data must be installed in the network card.
When installing a network card, the device driver that manages the network card must be installed in the computer's operating system. This driver will later tell the network card where in the memory the data blocks transmitted from the LAN should be stored. The network card must also be able to implement the Ethernet protocol.
The network card is not an independent autonomous unit, because the network card itself does not have a power supply but must use the power supply of the computer it is plugged into and is controlled by the computer. The network card can therefore be viewed as a semi-autonomous unit. When a network card receives an erroneous frame, it discards the frame without notifying the computer to which it is plugged. When the network card receives a correct frame, it uses an interrupt to notify the computer and deliver it to the network layer in the protocol stack. When the computer wants to send an IP data packet, it is handed down from the protocol stack to the network card, assembled into a frame, and sent to the LAN.
With the continuous improvement of integration, the number of chips on the network card continues to decrease. Although there are many types of network cards produced by various manufacturers, their functions are similar.
2. How to identify whether the network card is real or fake
Here we will introduce to you the conditions that a high-quality network card should have:
(1) Use spray tin Board
The circuit board of a high-quality network card is generally made of tin-sprayed board. The network card board is white, while the inferior network card is yellow.
(2) Use high-quality main control chip
The main control chip is the most important component of the network card. It often determines the performance of the network card, so the high-quality network card uses The main control chip should be a mature product on the market. Many inferior network cards on the market use older main control chips in order to reduce costs, which undoubtedly puts a discount on the performance of the network card.
(3) Most of them use SMT chip components
Except for electrolytic capacitors and high-voltage ceramic capacitors, most of the other resistive components used in high-quality network cards are more reliable and stable than plug-ins. SMT chip components. Most inferior network cards use plug-ins, which makes the heat dissipation and stability of the network card not good enough.
(4) Titanium-plated gold fingers
The gold fingers of high-quality network cards are made of titanium-plated gold, which not only increases its own anti-interference ability but also reduces the impact on other devices. interference, and the nodes of the gold finger are designed in an arc shape. Most inferior network cards are made of non-titanium-plated gold, and the nodes are also turned at right angles, which affects the performance of signal transmission.
3. The main functions of the network card are as follows:
1. Encapsulation and decapsulation of data The header and trailer are added to become an Ethernet frame. When receiving, the header and tail of the Ethernet frame are stripped off, and then sent to the upper layer;
2. Link management
Mainly CSMA/CD (Carrier Sense Multiple Access with Collision Detection, implementation of the Carrier Sense Multiple Access with Collision Detection protocol;
3. Encoding and decoding
That is, Manchester encoding and decoding.
Understanding of computer hardware: What is a computer sound card?
Sound card is also called audio card (called sound card in Hong Kong and Taiwan): Sound card is the most basic in multimedia technology The component is a piece of hardware that does a better job of converting sound waves/digital signals to each other. The basic function of a sound card is to convert original sound signals from microphones, tapes, and compact discs, and output them to sound equipment such as headphones, speakers, amplifiers, and tape recorders, or to make musical instruments emit beautiful sounds through the Music Equipment Digital Interface (MIDI).
How the sound card works
The sound card obtains the sound analog signal from the microphone, passes through the analog-to-digital converter (ADC), and uses the sound wave amplitude signal to sample and convert it into a series of digital signals, which are stored in the computer. middle. During playback, these digital signals are sent to a digital-to-analog converter (DAC), restored to analog waveforms at the same sampling speed, and then amplified and sent to speakers for sound production. This technology is called pulse code modulation (PCM).
The main functions of the sound card are as follows:
(1) It can record digital sound files. Through the control of the sound card and the corresponding driver, the signals from the microphone, radio recorder and other sound sources are collected, and then compressed and stored in the computer system's memory or hard disk;
(2) Compressed with a hard disk or laser disk The digitized sound files are restored into high-quality sound signals, which are amplified and released through the speakers;
(3) Process the digitized sound files to achieve a specific audio effect;
(4) Control the volume of the sound source, combine various sound sources, and make the reverberation function better;
(5) Use language synthesis technology to read text information through the sound card. Such as reading English words and sentences, playing music, etc.;
(6) Has preliminary audio recognition function, prompting the operator to use passwords to command the computer to work;
(7) Provides MIDI function , enabling the computer to control multiple electronic musical instruments with MIDI interfaces. Also, with the help of the driver, the sound card can output files stored in MIDI format to the corresponding electronic musical instruments and produce corresponding sounds. Make electronic musical instruments commanded by the sound card.
Several main types of sound cards
Since the development of sound cards, they are mainly divided into three interface types: board type, integrated type and external type to meet the needs of different netizens. Each type of product has its own advantages and disadvantages.
Card type: Card type products are the backbone of the market today. The products cover low, medium and high grades, with prices ranging from tens of yuan to thousands of yuan. Most of the early card-based products were ISA interfaces. Because this interface has low bus bandwidth, single function, and takes up too many system resources, it has been eliminated. PCI has replaced the ISA interface and has become the current popularity, and they have better capabilities. And compatibility, it supports plug-in and can be used, and it is very convenient to install and use.
Integrated: The sound card will only affect the sound quality of the computer, and has nothing to do with the system capabilities that PC netizens are more sensitive to.
Therefore, most netizens are satisfied with the need for a sound card that can be used, and are more willing to invest funds in parts that can enhance system capabilities.
Although the compatibility, ease of use and capabilities of board-type products can meet market needs, in order to pursue cheaper and simpler, integrated sound cards have emerged.
Such products are integrated on the motherboard. They do not occupy PCI interfaces, are cheaper, and have better compatibility. They can meet the vast majority of audio needs of ordinary Internet users, and are naturally favored by the market. favor. Moreover, the technology of integrated sound cards is also constantly improving. The multi-channel, low CPU occupancy and other advantages of PCI sound cards have also appeared on integrated sound cards. As a result, it has taken a dominant position and occupied most of the sound card market.
External sound card: It is an emerging thing exclusively launched by Innovation Group. It is connected to the PC through the USB interface and is easy to use and mobile. However, this type of product is mainly used in special environments, such as connecting laptops to achieve better sound quality. There are not many external sound cards on the market at present. Common ones include the innovative Extigy and Digital Music, as well as MAYA EX, MAYA 5.1 USB, etc.
Among the three types of sound cards, integrated products are low-priced and have increasingly mature technology, occupying a larger market share. Following the advancement of technology, this type of product still has very, very big prospects in the mid-to-low-end market
; PCI sound cards continue to become the backbone of the mid-to-high-end sound card field. After all, independent boards have great advantages in design and wiring. Authoritative, more suitable for the performance of sound quality; while the authority and cost of external sound cards are not obvious for home PCs, and they are still a marginal product that fills the gap.