Classification of computers

Super computer:
A computer consisting of hundreds of, thousands of or more processors that can compute a large and complex subject that cannot be completed by a common PC or server.
Is the most powerful computer, the fastest computing speed, the largest storage capacity of a class of computers, is the national level of scientific and technological development and the important symbol of comprehensive national strength.
Supercomputers have the strongest parallel computing power, primarily for scientific computing.
In the meteorological, military, energy, aerospace, prospecting and other fields to undertake large-scale, high-speed computing tasks.
Structurally, while supercomputers and servers can be multiprocessor systems, there is no real difference between them,
Modern supercomputers use cluster system more and pay more attention to the performance of floating-point arithmetic.
Network computer
1. Server
It refers to some high-performance computers, which can provide services through the network.
Compared with the ordinary computer, stability, security, performance and other aspects are required to be higher,
Therefore, the CPU, chipset, memory, disk system, network and other hardware and ordinary computers are different.
The server is the node of the network, which stores and processes 80% of data and information on the network, and plays an important role in the network.
They are high-performance computers that provide a variety of services to client computers, and their high-performance primary tables are computationally capable,
Reliable operation for a long time, strong external data throughput capabilities, and more.
The composition of the server is similar to the ordinary computer, also has the processor, the hard disk, the memory, the system bus and so on, it is specially developed for the specific network application,
There are many differences between server and microcomputer in processing capability, stability, reliability, security, expansibility and manageability.
The main servers are:
Network servers (DNS, DHCP), print servers, terminal servers, disk servers, mail servers, file servers, and so on.
2. Workstations
Based on personal computer and distributed network Computing, it is mainly oriented to professional application field,
With powerful data operations and graphics, image processing capabilities, designed to meet the professional areas of the design and development of high-performance computers.
The most prominent feature is the strong ability of graphic exchange, which has been applied rapidly in the field of graphic image, especially in computer aided design.
The operating system and application software used on the workstation are all placed on the server, as long as the system administrator completes the management and maintenance on the server,
Software upgrades and installations are only required once, and all computers in the entire network can use the new software.
With the advantages of cost saving, high security, easy management and maintainability, this is very attractive to network administrators.
Works by the network card's boot chip (bootrom) in a different form to the server issued a start request number,
After the server receives, according to the different mechanism, sends the boot data to the workstation, after the workstation downloads the boot data,
System control is transferred from the boot ROM to some specific area in memory and boots the operating system.
According to different start-up mechanism, the comparison of common diskless workstations can be divided into RPL and PXE. RPL is the abbreviation for the remote Initial program Load,
This technique is commonly used in Windows95. PXE is an upgrade to RPL, which is the abbreviation for Preboot execution environment.
The difference is that RPL is a static route, and PXE is a dynamic route,
Its communication protocol adopts TCP/IP, which realizes the efficient and reliable connection with the Internet.
It is commonly used in Windows98, Windows NT, Windows2000, Windows XP.
3. Hub
A network device that shares media, which can connect some machines to form a LAN,
The hub itself does not recognize the destination address. All ports on the hub contend for a shared channel of broadband, so as the number of network nodes increases,
As data is increased, the available bandwidth per node decreases. A hub transmits data in broadcast form, that is, to all ports.
If a host in the same local area network transmits data to Host B, the packet is broadcast on a hub-based network,
The same information is sent to all nodes on the network, and each terminal verifies the receipt by verifying the address information of the packet header.
Easy to cause network congestion, the vast majority of data traffic is invalid, resulting in a very low efficiency of the entire network data transmission.
Because the packets sent by each node can be heard, it is easy to bring some security risks to the network.
4. Switch
According to the need of transmitting information on both ends of the communication, the information to be transmitted is sent to the corresponding route according to the requirement by the auto-completion method.
is a communication system to complete the information exchange function of equipment, it is a hub upgrade products,
The appearance is very similar to a hub, which acts in much the same way as a hub.
But there are differences in performance:
Hubs use shared bandwidth to work, and switches use exclusive bandwidth.
All ports on the switch have exclusive channel bandwidth to ensure fast and efficient transmission of data on each port,
The user provides an exclusive, point-to-point connection, and the packet is sent only to the destination port, not to all ports.
Other nodes are very difficult to hear the information sent, so that in a lot of machines or large amounts of data, it is not easy to cause network congestion,
Ensure the security of data transmission, at the same time greatly improve the transmission efficiency, the difference between the two is more obvious.
5. Routers
A network device that is responsible for locating the path, and finding a network path with the least traffic from multiple paths to provide the user with communication.
Routers use routing tables to select paths for data transfer, and the routing table contains a list of network addresses and distances between addresses.
Use the routing table to find the correct path for the packet from its current location to the destination address.
Use the least-time algorithm or the optimal path algorithm to adjust the path of information delivery. After the router is generated from the switch,
Just as the switch is generated from the hub, the router and the switch also have a connection, not completely independent of the two devices.
Routers mainly overcome the inability of the switch to forward packets to the route.
The switch, router is a special network computer, its hardware base CPU,
Memory and interface, the Software Foundation is the network interconnection operating system iOS.
Switches, routers, and PCs, there are central processing unit CPUs, and different switches, routers,
Its CPU is generally not the same, the CPU is the switch, router processing center.
Memory is where switches, routers store information and data,
Cisco switches and routers have the following types of memory components:
ROM Storage switches,
Router power-on self-test,
Start the program and part or all of iOS.
The ROM in the switch and router is rewritable, so iOS can be upgraded.
RAM is similar to random memory on a PC, providing temporary information storage while preserving the current routing table and configuration information.
The NVRAM stores the boot configuration file for the switch and router, and the NVRAM is rewritable.
Flash Flash, which is erasable or programmable, is used to store other Cisco IOS versions for upgrades to the switch, router iOS.
The interface is used to connect the switch and router to the network, which can be divided into two kinds: LAN interface and WAN interface.
The number and type of interfaces vary depending on the switch and router model.
Common interfaces include the following:
High-speed synchronous serial port, can connect DDN, Frame relay (frames Relay), X.25,PSTN (analog telephone line).
Synchronous/asynchronous serial port, the software can be set to synchronize the operation mode.
The AUI port, which is the thick cable mouth. An external converter (AUI-RJ45) is generally required to connect the 10/100BASE-T Ethernet network.
ISDN port, which can be connected to an ISDN network (2B+D) and can be used as a LAN for Internet access.
The Aux port, which is an asynchronous port, is used primarily for remote configuration and can also be used for dial backup, which can be connected to a modem.
Supports hardware flow control (Hardware flow controls).
The console port, which is the asynchronous port, the primary connection terminal, or the computer running the terminal emulator,
Configure the switch, router locally. Hardware flow control is not supported.
Industrial control
A computer system which uses bus structure to detect and control the production process and its electromechanical equipment and process equipment.
The computer and process input and output (I/O) are made up of two major parts.
The computer is composed of a host, a input and an external disk drive, a tape drive, and so on.
A part of the process input/output channel is added outside the computer to complete the inspection data of the industrial production process into the computer for processing;
On the other hand, the computer should exercise the command of production process control, information into the control variables of industrial control object signal,
And then sent to the controller of the industrial control object. The controller is exercised to control the operation of the production equipment.
The main categories of industrial computer are:
IPC (PC Bus industrial pc),
PLC (Programmable control System),
DCS (Decentralized control system),
FCS (Fieldbus system),
CNC (CNC system).
1. IPC
PC Bus-based industrial computer because of its low price, high quality, large output, soft/hardware resources rich.
has been familiar with the vast number of technical personnel and recognition, which is the basis of industrial electric annoyance heat.
Its main components are industrial chassis, passive backplane and can be inserted into the various board cards, such as CPU cards, I/O cards.
Adopt the design and EMC technology of all steel casing, machine card layering filter, double positive pressure fan, etc.
To solve the industrial field of electromagnetic interference, vibration, dust, high/low temperature and other issues.
IPC has the following characteristics:
Reliability: Industrial PCs are available in dust, smoke, high/low temperature, moisture, vibration, corrosion and rapid diagnosis and maintainability.
Real-time: industrial PC real-time on-line detection and control of industrial production process,
Respond quickly to changes in working conditions, collect and output in time to adjust distress self-resetting to ensure the normal operation of the system.
Scalability: Industrial PC due to the use of the Backplane +CPU card structure, thus has a strong input and output function, up to 20 cards can be expanded,
It can be connected with various peripherals and boards such as the road controller, video surveillance system and vehicle detector in the industrial field to accomplish various tasks.
Compatibility: Can use both ISA and PCI and PICMG resources, and support various operating systems, multi-language assembly, multi-tasking operating system.
2, programmable controller (PLC)
PLC English full name Programmablelogiccontroller, Chinese is all called Programmable logic controller,
Definitions are:
A digital operation electronic system designed for use in industrial environments.
It uses a class of programmable memory for its internal storage program, to perform logical operations,
Order control, timing, counting and arithmetic operations, and other user-oriented instructions,
Various types of mechanical or production processes are controlled by digital or analogue input/output.
Programmable control system is a digital operation electronic system specially designed for application in industrial environment.
Using a programmable memory to perform operations such as logical operations, sequential control, timing, counting, and arithmetic operations in the internal storage,
Control all types of mechanical equipment or production processes with digital or analogue input and output.
is a new universal automatic control device which is applied in industrial environment, which is developed by combining computer technology with automation
is a replacement product of a traditional relay. With the rapid development of microelectronics and computer technology,
It has the characteristics of small size, convenient assembly and maintenance, simple programming, high reliability, strong anti-jamming ability, etc.
has been widely used in various fields of industrial control, and has greatly advanced the process of electromechanical integration.
3. Decentralized control system (DCS)
is a high-performance, high-quality, low-cost, flexible configuration of decentralized control system products,
Can constitute a variety of independent control systems, decentralized control system DCs, monitoring and Data acquisition system (SCADA),
It can meet the needs of process control and information management in various industrial fields.
The modular design of the system, the reasonable configuration of hardware and software and the ability of easy expansion can be widely used in decentralized control of large, medium and small power plants,
The transformation of power plant automation system and industrial production process control of steel, petrochemical, papermaking, cement and so on.
4. Fieldbus System (FCS)
is a full digital serial, two-way communication system.
In-system measurement and control devices such as probes, actuators and controllers can be connected, monitored and controlled.
In the classification of the Factory network, it is not only the local network of the Process Control and application of intelligent instrument, but also the embedded function of distributed control application on the network.
Due to its broad application prospects, a large number of foreign manufacturers have the strength to enter the strength of product development.
There are more than 40 types of fieldbus, compared with typical fieldbus: Ff,profibus,lonworks,can,hart,cc-link and so on.
5, CNC system (CNC)
Modern CNC system is a microprocessor or a special computer numerical control system, by storing in memory system program (software) to achieve control logic,
Realize some or all of the CNC function, and through the interface and peripheral equipment connection, called Computer Numerical Control, abbreviated to CNC system.
CNC machine tool is a new technology represented by the CNC system to the traditional machinery manufacturing industry infiltration of the formation of electromechanical integration products;
The technology range covers many areas:
(1) Mechanical manufacturing technology;
(2) Information processing, processing, transmission technology;
(3) automatic control technology;
(4) Servo drive technology;
(5) sensor technology;
(6) Software technology and so on.
Pc
1. Desktops (Desktop)
A separate computer, completely disconnected from other components, is relatively large in size compared to notebooks and netbooks,
Hosts, monitors and other devices are generally relatively independent, generally need to be placed on a computer desk or a dedicated workbench.
The desktop has the following features:
Heat dissipation: Has the advantage which the notebook computer cannot compare.
Extensibility: The chassis facilitates user hardware upgrades, such as optical drives, hard drives.
The chassis has an optical drive slot of 4-5 and a hard drive slot of 4-5. User-friendly future hardware upgrades.
Protective: All aspects of the protection of the hardware against dust. And the water resistance is good, in the notebook this development is not very good.
Clarity: The chassis open, key, restart key, USB, audio interface are in the chassis front panel, user-friendly use.
But the portability of desktops is poor, compared to notebooks is very convenient.
2, computer-integrated machine
The computer is a computer which consists of a monitor, a computer keyboard and a mouse.
Its chip, motherboard and monitor are integrated together, the monitor is a computer.
Some computers also have a TV reception, Av function, but also integrated software, can be used for specific industries dedicated machine.
3. Notebook computer (notebook or laptop)
In addition to keyboards, laptops provide trackpad or touch points, providing better positioning and input capabilities.
Laptops can be broadly divided into 6 categories:
Business, fashion, multimedia applications, Internet-based, learning, special purpose.
Business Type notebook:
Generally can be summarized as strong mobility, long battery life, business software more;
Multi-media application notebook:
Have a strong graphics, image processing capabilities and multimedia capabilities, especially the ability to play, for the enjoyment of products.
Most have a more robust discrete graphics card and sound card (both support HD) and have a larger screen.
Netbooks:
Portable and low-profile laptops with features such as Internet access, e-mail and instant messaging (IM)
Emphasis on portability, more for travel, travel and even public transport on the mobile internet.
Learning Type:
The body is designed as a notebook shape, using standard computer operation,
Fully integrated learning machine, electronic dictionary, repetition machine, point reading machine, student computer and many other machine functions.
Special use:
Services for professionals, can be in the heat, cold, low pressure, high altitude, strong radiation, war and other harsh environment, the use of
Some of the more cumbersome, such as the pre-Olympic Games in the "Asus Everest Base Camp IT service area" use of ASUS notebook computers.
4. Handheld Computer (PDA)
A small, lightweight, easy-to-use, practical, handheld computing device that runs on embedded operating systems and embedded application software.
It is simpler and lighter in terms of volume, function and hardware than laptop computers.
The core technology of PDA is embedded operating system, and the competition among various products is mainly in this.
A smartphone (Smartphone) is built on top of a handheld computer.
Smartphones provide users with enough screen size and bandwidth to carry around and provide a broad stage for software operation and content services.
5. Tablet PC
The tablet is proposed by Bill Gates, at least the X86 architecture, from Microsoft's proposed tablet concept products,
is a non-clamshell, no keyboard, small enough to fit into the ladies handbag, but a full-featured PC.
Embedded
Application-centric, microprocessor-based, software and hardware can be cut,
To adapt to the application system to function, reliability, cost, volume, power consumption and other comprehensive requirements of the special computer system.
It consists of four parts including embedded microprocessor, peripheral hardware device, embedded operating system and user's application.
Is the fastest growing field in the computer market, and it is a computer system with a wide variety of forms.
Embedded systems include almost every electrical device in life, such as handheld PDAs, calculators, TV set-top boxes, mobile phones, digital TVs,
Multimedia players, automobiles, microwaves, digital cameras, home automation systems, elevators, air conditioners, safety systems,
Vending machines, cellular telephones, consumer electronics, industrial automation instruments and medical devices.
The core components of embedded systems are embedded processors, divided into 4 categories:
That is, embedded microcontroller (micro Contrller Unit, MCU, commonly known as single-chip microcomputer),
Embedded microprocessor (Micro Processor Unit, MPU),
Embedded DSP Processor (Digital Signal PROCESSOR,DSP)
and embedded on-chip systems (System on CHIP,SOC).
Embedded microprocessors generally have 4 features:
1, the real-time and multi-tasking has strong support ability, can complete multi-tasking and has a short interrupt response time,
So that the internal code and real-time operating system execution time is minimized;
2, has a strong function of the storage area protection, this is due to the embedded system software structure has been modular,
In order to avoid the wrong cross-function between software modules, it is necessary to design powerful storage area protection function, and also benefit the software diagnosis.
3. Extensible processor structure to rapidly expand the high-performance embedded microprocessor to meet the application;
4, power consumption must be very low, especially for portable wireless and mobile computing and communication equipment in the battery-powered embedded systems.

Classification of computers