История и СИД
Computers can be divided into three main types depending on their size and power. Mainframe computers are the largest and most powerful. They usually fill a whole room and are sometimes referred to as mainframes or computer installations.
Computers are electronic machines, which can accept data in a certain form, process the data and give the results of the processing in a specified format as information.
Computers can be divided into three main types, depending on their size and power.
Mainframe computers are the largest and most powerful. They can handle large amounts of information very quickly and can be used by many people at the same time. They usually fill a whole room and are sometimes referred to as mainframes or computer installations. They are found in large institutions and government departments.
Minicomputers, commonly known as minis, are smaller and less powerful than mainframes. They are about the size of an office desk or smaller and are usually found in banks and offices. They are becoming less popular as microcomputers improve.
Microcomputers, commonly called as micros, are the smallest and least powerful. They can handle smaller amounts of information at a time and are ideal for use as home computers, but are also used in education and business. More powerful micros are gradually being produced; therefore they are becoming the most commonly used type of computers.
A computer can do very little until it is given some information. This is known as the input and usually consists of a program and some data.
A program is a set of instructions, written in a special computer language, telling the computer what operations and processes have to be carried out and in what order they should be done. Data, however, is the particular information that has to be processed by the computer, e.g. numbers, names, measurements.
Information in the form of data and programs is known as software, and mechanical parts that make up a computer system are called hardware. A standard computer system consists of three main sections: the Central Processing Unit (CPU), the main memory and the peripherals.
Perhaps the most influential component is the Central Processing Unit. Its function is to execute programs and coordinate the activities of all the other units. In a way, it is the brain of the computer. The unit consists of three main parts:
a) the Control Unit, which examines the instructions in the users program, interprets each instruction and causes the circuits and the rest of the components disk drives, monitors, etc. to be activated to execute the functions specified;
b) the Arithmetic Logic Unit (ALU), which performs mathematical calculations (+,-,etc.) and logical operations (and, or,etc.);
c) the registers, which are high-speed units of memory used to store and control information. One of these registers is the Program Counter (PC) which keeps track of the next instruction to be performed in the main memory. Another is the Instruction Register (IR) which holds the instruction that is currently being executed
The main memory holds the instructions and data which are currently being processed by the CPU. It has two types: RAM and ROM, both contained in electronic chips connected to the main board of the computer. RAM stands for Random-Access Memory and is the working area of the computer, that is, the basic location where the microprocessor stores the required information. All the information stored in the RAM is temporary. ROM is the acronym for Read-Only Memory, which implies that the processor can read and use the information stored in the ROM chip, but cannot put information into it. ROM chips have constant information, including instructions and routines for the basic operations of the CPU.
The peripherals are the physical units attached to the computer. They include storage devices and input/output devices.
Storage devices (floppy or hard disks) provide a permanent storage of both data and programs. Disk drives are used to handle one or more floppy disks. Input devices enable data to go into the computers memory. The most common input devices are the mouse and the keyboard. Output devices enable us to extract the finished product from the system. For example, the computer shows the output on the monitor or prints the results onto paper by means of a printer.
On the rare panel of the computer there are several ports into which we can plug a wide range of peripherals modems, fax machines, optical drives and scanners.
These are the main physical units of a computer system, generally known as the configuration.
1. Read the introductory text again and answer these questions:
2. Find in the text equivalents for the following words and word-combinations: usually, little by little, to fulfil, to perform, part, at the present moment, to denote, to connect, with the aid of.
3. Read the text. Do the tasks given below.
At the centre of the computer system is the CPU, which can be considered to be the “brain” of the computer. Its main components are the central processor and the main memory. The speed and capacity of these components have been greatly improved with each new generation of computers. In the first generation, the central processor was built from electronic valves, which were rather unreliable. The second generation used transistors. The third generation used integrated circuits. The fourth generation of computers uses microprocessors. These are contained on electronic chips, which are slices of silicon with thousands of electronic components and circuits engraved on them.
Early computers used magnetic cores in their main memory but
fourth generation computers use much smaller and more powerful electronic memory chips.
The two parts of the central processor are the Control Unit (CU) and the Arithmetic and Logic Unit (ALU).
The control unit controls all the other units in the computer system. It decodes the program instructions and makes sure they are carried out in the correct sequence. The arithmetic and logic unit, on the other hand, performs the calculations and data manipulation e.g. comparing, sorting and combining data.
These units have small, short-item storage areas called registers, which are used for special tasks. For example, the register in the CU known as the program computer is used to hold the address of the next instruction to be carried out. The register in the ALU known as the accumulator is used to temporarily hold the data item currently being processed.
Each unit of the CPU is connected by a group of wires called a bus. There are data buses for carrying data from one unit to another, control buses for sending control signals to each unit and address buses for accessing each part of the main memory.
The power of CPU is partly determined by its speed. This is controlled by a clock in the processor, which sends out regular pulses to each unit to keep them in step. The clock pulse rate is measured in megahertz (MHz).
A computer can be made more powerful by connecting a second processor to work in parallel with the first one. When computers are connected in a network configuration, the processing can be shared by the CPUs. This distributed processing make the system much more powerful.
input processor output
Expenses (e.g. payroll, services, publicity)
on the monitor or in printed form
software peripheral devices MONITOR
floppy disk HARDWARE INPUT port
OUTPUT Central Processing Unit
1 The brain of the computer.
2 Physical parts that make up a computer system.
3 Programs which can be used on a particular computer system.
4 'Pile information which is presented to the computer.
5 Results produced by a computer.
6 Hardware equipment attached to the CPU.
7 Visual display unit.
8 Small device used to store information. Same as 'diskette'.
9 Any socket or channel in a computer system into which an input/output device may be connected.
4. Read and guess.
Read these slogans or quotations, and say what computer element they refer to.
1 a) 'Point and click here for power.'
b) 'Obeys every impulse as if it were an extension of your hand.'
2 a) 'Displays your ideas with perfect brilliance.'
b) 'Sec the difference - sharp images and a fantastic range of colours.'
3 a) 'I love this drive. It's quiet and fast.'
b) 'With this it's easy to back up your data before it's too late.'
4 a) 'Power and speed on the inside.'
b) 'Let your computer's brain do the work.'
5 a) '... a big impact on the production of text and graphics.'
b) 'Your choice: a laser powerhouse.'
6 a) 'Your fingers will hardly know they're working.'
b) 'Choose a full 105-key layout, and type with efficiency.'
5. Agree or disagree with the following statements, make the false ones true:
microcomputer (portable) microcomputer (desktop PC) mainframe minicomputer
1. According to the speaker:
a) a mainframe computer is less powerful than a minicomputer.
b) a mainframe is more powerful than a minicomputer.
c) a mainframe is not very powerful but can
execute jobs very rapidly.
2 Mainframe computers arc used by:
a) students and teachers in schools.
b) executives and businessmen.
c) large organizations that need to
process enormous amounts of data.
3 'Multitasking' means:
a) access to a minicomputer through terminals.
b) doing a number of tasks at the same time.
c) connection to a 'host' computer by a network
so that many users have access to data
4 The most suitable computers for home use are:
c) microcomputers (PCs).
5 The smallest and least powerful computers are
b) desktop PCs.
c) laptops and notebook computers.
Working in pairs make up dialogues discussing the following problems. You are a computer novice.
1. Ask another student to describe the computer. Touch upon these aspects hardware and software CPU, main memory, peripherals.
2. Discuss main types of computers giving both their advantages and disadvantages.
Any computer is, architecturally, like any other
computer in the early days of computers.
However, there are differences. They are the following: an early processor used to be made of thousands of vacuum tubes. Reliability was measured in mere hours between failures, and the cooling plant was often larger than the computer itself. Then the transistor was invented. The number of them was enormous in each mainframe. Besides, in computers of the 1950s, the transistors, diodes, resistors, capacitors and other components were mounted on printed-circuit (PC) cards. A typical 5-in. card contained a dozen transistors and a hundred other parts. A card might have contained a single flip-flop and a thousands cards were required to build each computer.
In the early 1960s semiconductors makers created a wholly new technology: a whole flip-flop could be integrated. Several of integrated circuits (ICs) could be mounted on a single printed card. Soon, improved fabrication processors enabled even more complex circuit to be created in a single IC. The new technology was called medium-scale integration (MSI), and the older technology was labeled small-scale integration (SSI). The progress towards smaller computers continued.
If used for computers discrete transistors were too costly and unreliable, they were too large and too slow.
In the 1960s advances in microelectronic components led to the development of the minicomputer, followed more recently by an even smaller microcomputer. Both have filled a need for small relatively flexible processing systems able to execute comparatively simple computing functions at lower cost.
In 1971, Intel Corp. delivered the first microprocessor, the 4004. All the logic to implement the CPU, the central processing unit, of a tiny computer was put onto a silicon chip less than 1/4-in square. That design was soon followed by many others. The progress towards smaller computers is likely to continue: there is already talk of nano-computers pico-computers. When the central processing unit (CPU) of a computer is implemented in a single or very small number of integrated circuits, we call it a microprocessor. When a computer incorporates a microprocessor as its major component, the resulting configuration is called a microcomputer. When the entire computer, including CPU, memory and input-output capability, is incorporated into a single IC, we also call that configuration a microcomputer. To distinguish between the two microprocessor types, we call the latter a one-chip microcomputer.
Modern computer and microelectronic devices have interacted so closely in their evolution that they can be regarded as virtually symbiotic. Microelectronics and data processing are linked.
1. A. The input usually consists of a program and some data.
B. A wide range of peripherals can be plugged into ports on the rare panel of the computer.
C. CPU is considered to be the “brain” of the computer.
D. There exist two types of the main memory.
До тех пор пока в компьютер не введена некоторая информация, он способен выполнить совсем немногие операции.
2. A. A computer can do very little although it is given some information.
B. Unless a computer is given some information it wont work at all.
C. A computer can do very little until it is given some information.
3. The power of CPU is partly determined by its speed.
A. Мощность ЦП не зависит от скорости его работы.
B. Мощность ЦП полностью определяется скоростью его работы.
C. Мощность ЦП частично определяется скоростью его работы.
8. disk drive
В. гибкий диск
D. печатная плата
9. The main components of the computer are the central processor and the … .
10. The second generation of computers used … .
11. Microprocessors are used by the … generation of computers.
12. The register in the ALU is known as the … .
13. The clock pulse rate in computers is measured in … .
14. Physical units attached to the computer are known as … .
15. A set of instructions written on a special computer language is called a … .
16. Information in the form of data and programs is known as … .
17. The unit, which performs mathematical and logical calculations is known as … … … .
18. The most common input devises are the … and the … .
19. The computer shows the output on the … .
20. The computer prints the results on the … .
21. … is the particular information that has to be processed by the computer .
A. program B.routine C. data
22. Each unit of the CPU is connected by a group of wires called a … .
A. board B. track C. bus D. register
23. … are ideal for use as home computers.
A. minicomputers B. microcomputers C. mainframe computers
24. Mechanical parts that make up a computer system are called
A. software B. configuration C. peripherals D. hardware
25 … chips have “constant ” information.
A. RAM B. ROM
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