1. 1 hardware knowledge
1. 1. 1 computer structure
1. 1.2 memory
Memory, also known as memory, is also commonly known as main memory. It is the main component of computer, relative to external memory. The internal memory includes registers, cache and main memory. The register is in the CPU chip, and the cache is also made in the CPU chip at present, while the main memory is composed of several memory chips inserted into the memory slot of the motherboard. The quality and capacity of memory will affect the running speed of the computer.
The commonly used memories of microcomputers are magnetic core memory and semiconductor memory. At present, the memories of microcomputers are all semiconductor memories.
Semiconductor memory is divided into random access memory (RAM), also known as read-write memory. Read-only memory (ROM for short)
1. random access memory
Random access memory (RAM) is a kind of memory that can read and write data randomly, also called read/write memory. RAM has the following two characteristics: first, it can be read and written. Do not destroy the original storage content when reading, and only modify the original storage content when writing. Second, RAM can only be used to temporarily store information. Once the power is cut off, the stored content disappears immediately, which means it is changeable. RAM is usually composed of MOS semiconductor memory, which can be divided into dynamic RAM and static RAM according to the mechanism of storing data. DRAM is characterized by high integration and is mainly used for large-capacity memory. SRAM is characterized by fast access speed and is mainly used for cache memory.
2. Read-only memory.
ROM is read-only memory. As the name implies, its characteristic is that it can only read the original content, and users can't write new content. The original storage content is written once by the manufacturer using mask technology and kept permanently. Generally used to store special fixed programs and data. Read-only memory (ROM) is a non-volatile memory. Once the information is written, there is no need for an external power supply to save the information, and it will not be lost due to power failure.
According to whether it can be rewritten online, it can be divided into ROM that cannot be rewritten online and ROM that can be rewritten online. Roms that cannot be rewritten online include mask ROM, programmable ROM(PROM) and erasable programmable ROM (EPROM). Roms that can rewrite content online include electrically erasable programmable ROM(EEPROM) and flash ROM.
3.CMOS memory (complementary metal oxide semiconductor memory)
CMOS memory is a chip that can store data with little power. Because of its low energy consumption, CMOS memory can be powered by a small battery integrated on the motherboard and can be automatically charged when the computer is turned on. Because CMOS chips can get power continuously, they can save important data about computer system configuration even after shutdown.
1. 1.3 input and output structure and equipment
1. 1.4 Basic knowledge of embedded system
1.2 operating system knowledge
The basic concept of 1.2. 1
An operating system is a collection of system software that manages computer hardware resources, controls the operation of other programs and provides interactive interfaces for users. Operating system is a key part of computer system, which is responsible for managing and configuring memory, determining the priority of system resource supply and demand, controlling input and output devices, operating network and managing file system. There are many kinds of operating systems, which can be installed on various devices from simple to complex, from the embedded operating system of mobile phones to the large operating system of supercomputers. At present, the popular modern operating systems mainly include Android, BSD, iOS, Linux, Mac OS X, Windows, Windows Phone and z/OS. Except for a few operating systems such as Windows and z/OS, most of them are Unix-like operating systems.
1.2.2 Management function of operating system
1.3 system configuration method
1.3. 1 system configuration technology
1.3.2 system performance
1.3.3 system reliability
1.4 simulation training questions
Chapter II Basic knowledge of system development and operation
2. 1 system development foundation
2. 1. 1 Requirements Analysis and Design Method
2. 1.2 development environment
2. 1.3 Examination review method
2. 1.4 Basic knowledge of project management
2. 1.5 system auditability
2.2 knowledge of system operation and maintenance
2.2. 1 system operation
system maintenance
2.3 Simulation training problems
Chapter III Network Technology
3. 1 network architecture
3. 1. 1 network topology
3. 1.2 OSI/RM
3. 1.3 application layer protocol
3. 1.4 transport layer protocol
3. 1.5 network layer protocol IP
3. 1.6 data link layer protocol
3. 1.7 physical address
Information is stored in memory in bytes. In order to store or obtain information correctly, each byte unit is given a unique memory address, which is called physical address, actual address or absolute address. Addresses are numbered from 0, and 1 is added in sequence every time, so the physical address space of the memory increases linearly. Represented by binary number, it is an unsigned integer, and the writing format is hexadecimal number.
It is the address signal appearing on the external address bus of CPU that addresses the physical memory, which is the final result of address conversion. It is used for cell addressing at memory chip level, corresponding to the address bus connected between the processor and CPU.
3.2 Coding and transmission
3.2. 1 modulation and coding
Modulation is a process of processing the information from the signal source and adding it to the carrier wave to make it a form suitable for channel transmission, even if the carrier wave changes with the signal. Generally speaking, the information of signal source (also called signal source) contains DC component and lower frequency component, which is called baseband signal. Baseband signals can not be used as transmission signals, but must be converted into signals with very high relative baseband frequency to be suitable for channel transmission. This signal is called a modulated signal, and the baseband signal is called a modulated signal. Modulation is realized by changing the amplitude, phase or frequency of the high-frequency carrier signal, that is, the carrier signal of the message, so that it changes with the amplitude of the baseband signal. Demodulation is the process of extracting baseband signal from carrier for processing and understanding by target receiver (also called receiver).
Encode characters, numbers or other objects into numbers by a predetermined method, or convert information and data into prescribed electric pulse signals. Coding is widely used in computer, television, remote control and communication fields. Coding is the process of converting information from one form or format to another. Decoding is the reverse process of coding.
transmission technology
Transmission technology transmission technology refers to the technology that components use the transmission capacity of different channels to form a complete transmission system, so that information can be transmitted reliably. Transmission system is an important part of communication system, and the transmission technology mainly depends on the transmission characteristics of specific channels.
Transmission control
3.2.4 Switching technology
Switching technology can identify the MAC address information in the data frame, forward it according to the MAC address, and record these MAC addresses and corresponding ports in an internal MAC address table. At present, the two-layer switching technology has matured. From the hardware point of view, layer 2 switches's interface module exchanges data through high-speed backplane/bus (the speed can be as high as several tens of Gbps), and layer 2 switches generally contains ASIC (application specific integrated circuit) chips specially used for packet forwarding, so the forwarding speed can be very fast.
3.2.5 Public networks and leased lines
A leased line refers to a telephone line leased from a telephone company to provide a permanent connection from a local area network (LAN) to an Internet service provider or a wide area network (WAN). The leased line bypasses the switching equipment of the local exchange telecommunications bureau (LEC), so it does not need to be started before each data transmission, and they are always connected. If the line is long-distance (between towers), then a long-distance telecommunications company is needed, just like LEC at the other end of the link. Other telecom companies, such as MCI, can also provide LEC bypass facilities in different urban areas. Because the organization will pay a fixed rent for the line according to the contract, it is called "leased line".
3.3 Network
3.3. 1 network classification
local area network
3.3.3 General structure of people
3.3.4 WAN and remote transmission services
3.3.5 Internet
3.3.6 Access network and access technology
network performance
3.4 Network communication equipment
3.4. 1 transmission medium and communication cable
3.4.2 All kinds of communication equipment
3.5 Network connection equipment
3.6 Network software system
3.6. 1 network operating system
administration of networks
3.6.3 Network Applications and Services
3.7 Simulation Training Problem
Chapter IV Network Security
4. 1 safety calculation
4. 1. 1 confidentiality and integrity
4. 1.2 illegal intrusion and virus protection
4. 1.3 Availability
4. 1.4 safety protection
4. 1.5 LAN security
4.2 Risk management
Risk analysis and assessment
Risk response measures
4.2.3 Internal control
4.3 Simulation Training Problem
Chapter V Standardization Knowledge
5. 1 formulation and acquisition of standards
5. 1. 1 formulation and acquisition of standards
5. 1.2 standardization of environmental and safety assessment
5.2 Standardization of information system infrastructure
5.2. 1 standard
5.2.2 Open Systems Interconnection Standard
Data exchange standard
safty standard
5.3 Standardization Organization
5.4 Simulation Training Problem
Chapter VI Basic Knowledge of Informatization
6. 1 information awareness
6.2 Global, National and Enterprise Informatization
6.2. 1 global informatization
6.2.2 National Informatization
6.2.3 Enterprise Informatization
6.3 Enterprise Information Resource Management Foundation
6.3. 1 Overview of enterprise information resource management
6.3.2 Management Methods of Enterprise Information Resources
6.4 Internet laws and regulations
6.5 Network Personal Information Protection Rules
6.6 Simulation Training Problem
Chapter VII Computer Professional English
7. 1 Computer English
7. 1. 1 vocabulary part
7. 1.2 reading section
7.2 Professional English for Network Technology
7.3 Professional English for Network Security