CHAPTER II
Basic Course of EnGlish
Unit 1 Ex.1. Read the text. What is a Personal Computer (PC)
A personal computer generally is a low-cost machine that can perform most of the functions of larger computer but use software oriented toward easy, single-user applications. A personal computer is an electronic device that can receive a set of instructions called program and then carry them out. A computer is called hardware because it has no intelligence by itself. A computer system is a combination of four elements: hardware, software, procedures, and data/information.
Software are the programs that tell the hardware how to perform a task. Without software instructions, the hardware doesn’t know what to do.
Let's take a look at some hardware of a typical desktop computer.
The microprocessor ("brain") of the computer system is called the central processing unit (CPU). The CPU oversees almost everything that a computer does. It is generally composed of the main memory, control unit, and arithmetic-logic unit. It constitutes the physical heart of the entire computer system; various peripheral equipment is linked to it, including input/output devices and auxiliary storage units.
Memory is a very fast storage to hold data. It has to be fast because it connects directly to the microprocessor. There are several specific types of memory in a computer:
– Random-access memory (RAM) stores information the computer is currently working with. There is a dynamic (DRAM) and static (SRAM) memory. Chips of a dynamic memory are used as the main RAM of a computer. Chips of static memory are used as an auxiliary memory (cache memory) which is intended for optimization of processor’s operation.
– Read-only memory (ROM) is a permanent type of memory storage, which the computer uses for important data that does not change. ROM is capable to store the information for a long time, even when the computer is switched off.
– Basic input/output system (BIOS) is a type of ROM that the computer uses to establish basic communication when it is turned on. It is used to enter information and instructions into a computer for storage or processing.
– Cache is a supplementary memory system that temporarily stores frequently used instructions and data for quicker processing by the central processing unit.
– Virtual memory is the space on a hard disk to store data and swap it in and out of RAM as needed. It is a scheme that gives users the illusion of working with a large block of memory space (perhaps even larger than real memory), when in actuality most of their work is on a disk.
Motherboard is the main circuit board where you connect all internal components.
Power supply is an electrical transformer, which regulates the electricity used by the computer.
Hard disk is a large-capacity permanent storage to hold information such as software, documents and photos.
Computers have four distinguishing characteristics:
1. Computers perform all operations electronically.
2. Computers have an internal storage capacity.
3. Computers receive operational instructions from stored programs.
4. Computers can modify program execution by making logical decisions.
The modern world of high technology could not be possible without computers. Different types and sizes of computers find uses throughout our society. They are used for the storage and handling of data, secret governmental files, information about banking transactions and so on. Computers have opened up a new era in manufacturing and they have enhanced modern communication systems. They are essential tools in almost every field of research, from constructing models of the universe to producing tomorrow’s weather reports. Using of different databases and computer networks make available a great variety of information sources.
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