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Студенческий документ № 000064 из ДГТУ (бывш. РИСХМ)

Computer is a programmable electronic machine that processes data and performs calculations and other symbol-manipulation tasks. It can take information from a person through the keyboard or mouse, from a device like CD or floppy disc or from the network through a modem. There are three types of machines: the digital computer, which manipulates information coded as binary numbers, the analog computer, which works with continuously varying quantities; and the hybrid computer which has characteristics of both analog and digital computers.

Digital computers are widely spread and corresponding to their size and intended use they could be divided into four types.

Microcomputers are the smallest used in Small business. at home, and in schools. They are usually single-user machines.

Laptop is a transportable computer, the best partner of yours when going somewhere on business, particularly in conferences, meetings, talks etc. Every dignified businessman uses such device.

Mainframes which can often service several hundred users simultaneously are found in large organizations, such as national companies and government departments.

Supercomputers are mostly used for extremely complex scientific tasks, such as analyzing the results of nuclear physics experiments and weather forecasting. The mechanical, electrical and electronic components of a computer System are called hard Ware. A collection of programs and procedures for making a computer perform a specific task is called software. Software is created by programmers and is either distributed on a suitable medium. such as a floppy disc, built into the computer in the form of firm ware. Examples of software include operating System, compilers and application programs. No computer can function without on form of software.

The main component of a computer, so to say, the very brain of it that executes individual program and controls the operation of other parts is the central processing unit (CPU). It includes the arithmetic and logic unit that carries out all calculations and logical operations, and control unit, which helps to run information around the system, since it decodes, synchronizes and executes program instructions.

The next important component of a computer is called "random access memory" or RAM. The memory is considered "random access" because the memory locations can be accessed directly rather than requiring sequential access. It means that the data can be selected without having to skip over earlier data first This is the way that, for example, a CD, DVD will behave. The CPU load application programs and the data they need into RAM before they can perform any processing. RAM is always supplemented by virtual memory, which increases the number of applications that can be run simultaneously. Virtual memory-space on a hard disc used to temporarily store data and Swap it in and out of RAM as needed. RAM is the short-term memory of the computer. It is volatile, which means that any information stored in it will be lost if power goes out. A permanent type of memory storage used by the computer for important data that does not change is called read-only memory (ROM). It does not lose its components when power is removed. ROM contains programs that are critical to the operation of the computer, for example, the instructions necessary to boot the computer when it is turned on.

BIOS (basic input/output system) is a type of ROM that is used by the computer to establish basic communication when the computer is turned on. Cache is a special memory subsystem with in a computer that temporarily holds data or program instructions to improve overall computer performance. Most caches copy data or from a standard computer memory (RAM) to a type of memory that allows faster data access by the CPU.

Hard disc (Sometimes called Winchester) is large-capacity permanent storage used to hold information such as programs and documents. Needless to say, that memory is one of the most important components of every computer. The larger the memory is the more possibilities are available and can be realized. Memory capacity (computer memory size) is measured in bytes, kilobytes. megabytes, or gigabytes. Byte is the sufficient computer memory to store a single character of data in bits (binary digits, e.g. 1 or O). A byte usually contains eight bits.

No doubt, the computer is a very complicated Compound device, which particularities and especially all the details of its (activities) are beyond the reach of just an average man in the street. but nevertheless each more or less experienced user who wants to acquire a computer is always interested (besides the volume and rate of its memories) in parameters of its components, such as motherboard and video board or video adapter. Of course these parameters must depend on the purposes which his computer will be targeted to.

Motherboard is the main circuit board of the computer that all of the others internal components connect to. Typically, the motherboard contains the CPU, BIOS, memory, mass storage interfaces, serial and parallel ports expansion slots, and all the controllers required to control standard peripheral devices, such as the display screen, keyboard, and disc drive. Other circuit boards are called add-ons or expansion boards.

Because the motherboard contains the CPU, all other chips attached to the motherboard can access the CPU directly without going through the bus i.e. through the wires that provide the routes of transmitting data. Hence it is possible to improve the parameters of your computer if you change or add some new chips. E.g. to add memory to your system you may be able just only to insert additional chips onto the motherboard.

On most PCs, it is possible to replace the motherboard to upgrade to a faster microprocessor. Replacing the motherboard in proves performance of all its components in addition to adding a faster CPU. Besides that, by replacing everything at once you can avoid possible compatibility problems.

Video board is located on an expansion board and inserted into a slot in the computer to provide it with the ability to display a video image. The parameters of this device are very important for

the multimedia purposes. Sound card is used by the computer to record and play audio by converting analog Sound into digital information and vice versa.

Graphics card translates image data from the computer into a format that can be displayed by the monitor.

SCSI (pronounced "skuzzy"), is acronym for small computer system interface. One type of standard interface used to connect computers to devices such as hard discs, printers, scanners. and CD-ROM drivers. SCSI interfaces provide for faster data transmission rates than standard Serial and parallel ports.

Port (an external connection) - the Socket that is used to connect the cable for a peripheral device to. The computer has different ports:

1. parallel port is commonly used to connect a printer

2. Serial port is typically used to connect an external modem, universal Serial bus (USB) is an external connection. The buses connect the computer to all peripheral devices

3. AGP (accelerated graphics ports) is a very high-speed connection used by the graphics card to interface with the computer.

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