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Arithmetic/logic: unit (ALU)
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The ALU is capable of performing two classes of operations: Arithmetic and logic.
The set of arithmetic operations that a particular ALU supports may be limited to adding and subtracting or might include multiplying or dividing, trigonometry functions (sine, cosine, etc) and square roots. Some can only operate on whole number (integers) whilst others use floating point to represent real numbers - albeit with limited precision. However, any computer that is capable of performing just the simplest operations can be programmed to break down the more complex operations into simple steps that it can perform. Therefore, any computer can be programmed to perform any arithmetic operation - although it will take more time to do so if its ALU does not directly support the operation. An ALU may also compare numbers and return Boolean truth values (true or false) depending on whether one is equal to, greater than or less than the other ("is 64 greater than 65?").
Logic operation ones involve Boolean logic: AND, OR, XOR and NOT. These can be useful both for creating complicated conditional statements and processing Boolean logic.
Superscalar computers contain multiple ALUs so that they can process several instructions at the same time. Graphics processors and computers with SIMD and MIMD features often provide ALUs that can perform arithmetic on vectors and matrices.
Give Russian equivalents.
To be capable, set, to support, to add, to subtract, to multiply, to divide, square root, whole number, floating point, precision, involve, superscalar, to contain.
Do the test.
1. The ALU is capable of performing … operations.
a) arithmetic and logic
b) logic
c) arithmetic
2. The set of arithmetic operations that ALU supports may be limited to…
a) multiplying
b) adding and subtracting
c) dividing
3. … computer can be programmed to perform any arithmetic operation.
a) Some
b) many
c) any
4 An ALU may also… numbers and return Boolean truth values (true or false).
a) add
b) compare
c) include
5 Logic operation ones involve….
a) Boolean logic
b) AND
c) OR
Module 5
LESSON 1
Read and translate the text.
Memory
Magnetic core memory was popular main memory for computers through the 1960s until it was completely replaced by semiconductor memory.
A computer's memory may be viewed as a list of cells into which numbers may be placed or read. Each cell has a numbered "address" and can store a single number. The computer may be instructed to "put the number 123 into the cell numbered 1357" or to "add the number that is in cell 1357 to the number that is in cell 2468 and put the answer into cell 1595." The information stored in memory may represent practically anything. Letters, numbers, even computer instructions may be placed into memory with equal ease. Since the CPU does not differentiate between different types of information, it is up to the software to give significance to what the memory sees as nothing but a series of numbers.
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In almost all modern computers, each memory cell is setup to store binary numbers in groups of eight bits (called a byte). Each byte is able to represent 256 different numbers; either from 0 to 255 or -128 to +127. To store larger numbers, several consecutive bytes may be used (typically, two, four or eight). When negative numbers are required, they are usually stored in two's complement notation. Other arrangements are possible, but are usually not seen outside of specialized applications or historical contexts. A computer may store any kind of information in memory as long as it can be somehow represented in numerical form. Modern computers have billions or even trillions of bytes of memory.
The CPU contains a special set of memory cells called registers that can be read and written too much more rapidly than the main memory area. There are typically between two and one hundred registers depending on the type of CPU. Registers are used for the most
frequently needed data items to avoid having to access main memory every time data is needed. Since data is constantly being worked on, reducing the need to access main memory (which is often slow compared to the ALU and control units) greatly increases the computer's speed.
Give Russian equivalents.
Magnetic core memory, semiconductor, may be viewed, cell, numbered, to store, a single number, with equal ease, it is up to, software, to give significance, each, to be able to, consecutive, negative numbers, required, stored in two's complement notation, arrangements, possible, specialized applications, data items, to avoid, to access, constantly, reducing, to increase the computer's speed.
LESSON 2
Write down into your vocabulary
Read-only memory, pre-loaded, contents, to be erased, to turn off, to retain, indefinitely, hard disk, random access memory, frequently, to turn on, firmware, to reset, notionally, flash memory, to blur the distinction, conventional, cache, on the programmer's part.
Read and translate the text.
Memory (II)
Computer main memory comes in two principal varieties: random access memory or RAM and read-only memory or ROM. RAM can be read and written to anytime the CPU commands it, but ROM is pre-loaded with data and software that never changes, so the CPU can only read from it. ROM is typically used to store the computer's initial start-up instructions. In general, the contents of RAM are erased when the power to the computer is turned off while ROM retains its data indefinitely. In a PC, the ROM contains a specialized program called the BIOS that orchestrates loading the computer's operating system from the hard disk drive into RAM whenever the computer is turned on or reset. In embedded computers, which frequently do not have disk drives, all of the software required to perform the task may be stored in ROM. Software that is stored in ROM is often called firmware because it is notionally more like hardware than software. Flash memory blurs the distinction between ROM and RAM by retaining data when turned off but being rewritable like RAM. However, flash memory is typically much slower than conventional ROM and RAM so its use is restricted to applications where high speeds are not required.
In more sophisticated computers there may be one or more RAM cache memories which are slower than registers but faster than main memory. Generally computers with this sort of cache are designed to move frequently needed data into the cache automatically, often without the need for any intervention on the programmer's part.
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LESSON 3-4
Write down into your vocabulary
| hard disks to be common I/O devices to provide keyboard mouse display printer floppy disks both inputs and outputs networking another form Engine Control Unit | steering wheel oxygen sensor to monitor speed each wheel gauge spark ignition circuits fuel injection system digital wristwatch button liquid crystal display tiny to contain |
Read and translate the text.
Input/Output (I/O)
Hard disks are common I/O devices used with computers.
I/O is the means by which a computer receives information from the outside world and sends results back. Devices that provide input or output to the computer are called peripherals. On a typical personal computer, peripherals include inputs like the keyboard and mouse, and outputs such as the display and printer. Hard disks, floppy disks, and optical discs serve as both inputs and outputs. Computer networking is another form of I/O. Practically any device that can be made to interface digitally may be used as I/O. The computer in the Engine Control Unit of a modernautomobile might read the position of the pedals and steering wheel, the output of the oxygen sensor and devices that monitor the speed of each wheel. The output devices include the various lights and gauges that the driver sees as well as the engine controls such as the spark ignition circuits and fuel injection systems. In a digital wristwatch, the computer reads the buttons and causes numbers and symbols to be shown on the liquid crystal display. Often, I/O devices are complex computers in their own right with their own CPU and memory. A graphics processing unit might contain fifty or more tiny computers that perform the calculations necessary to display 3D graphics. Modern desktop computers contain many smaller computers that assist the main CPU in performing I/O.
Module 6
LESSON 1-2
Read and translate the text.
Multitasking
While a computer may be viewed as running one gigantic program stored in its main memory, in some systems it is necessary to give the appearance of running several programs simultaneously. This is achieved by multitasking i.e. having the computer switch rapidly between running each program in turn. One means by which this is done is with a special signal called an interrupt which can periodically cause the computer to stop executing instructions where it was and do something else instead. By remembering where it was executing prior to the interrupt, the computer can return to that task later. If several programs are running "at the same time", then the interrupt generator might be causing several hundred interrupts per second, causing a program switch each time. Since modern computers typically execute instructions several orders of magnitude faster than human perception, it may appear that many programs are running at the same time even though only one is ever executing in any given instant. This method of multitasking is sometimes termed "time-sharing" since each program is allocated a "slice" of time in turn.
Before the era of cheap computers, the principle use for multitasking was to allow many people to share the same computer.Seemingly, multitasking would cause a computer that is switching between several programs to run more slowly — in direct proportion to the number of programs it is running. However, most programs spend much of their time waiting for slow input/output devices to complete their tasks. If a program is waiting for the user to click on the mouse or press akey on the keyboard, then it will not take a "time slice" until the event it is waiting for has occurred. This frees up time for other programs to execute so that many programs may be run at the same time without unacceptable speed loss
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Write down into your vocabulary.
May be viewed, it is necessary to give the appearance, simultaneously, to run a program, is achieved by multitasking, having the computer switch rapidly, means, interrupt, cause the computer to stop executing, something else instead, to execute a program, can return, several orders of magnitude faster, each time, perception, may appear, to share, to allocate, slice, turn, cheap, to allow, to complete, event, to occur, to free up, unacceptable speed loss.
Match the word-combinations
| 1. Компьютер можно рассматривать как 2. Программа, сохраненная в главной памяти 3. Достигается мультизадачностью 4. Запуск каждой программы по очереди 5. Одно средство с помощью которого 6. Вызывать остановку выполнения 7. Вызывая переключение каждый раз 8. На несколько порядков быстрее 9. Может показаться, что 10 Нажать на мышь | a. One means by which b. to click on the mouse c. several orders of magnitude faster d. a computer may be viewed as e. program stored in its main memory f. it may appear that g. is achieved by multitasking h. causing a program switch each time i. running each program in turn j. cause the computer to stop executing |
Translate the parts of the sentences into English
- Giving the appearance of running several programs simultaneously is achieved by быстрым переключением каждой программы по очереди.
- Multitaskingis done with a special signal, который называется прерыватель,
- The interrupt can periodically cause the computer to stop выполнение инструкции и вместо нее выполнять что-нибудь другое.
- This frees up time for other programs to execute so that много программ можно было запустить без неприемлемой потери скорости.
- The principle use for multitasking was позволить многим людям пользоваться одним и тем же компьютером.
LESSON 3
Read and translate the text.
Multiprocessing
Cray designed many supercomputers that used heavy multiprocessing.
Some computers are designed to distribute their work across several CPUs in a multiprocessing configuration, a technique once employedonly in large and powerful machines such as supercomputers, mainframe computers and servers. Multiprocessor and multi-core (multiple CPUs on a single integrated circuit) personal and laptop computers are now widely available, and are being increasingly used in lower-end markets as a result.
Supercomputers in particular often have highly unique architectures that differ significantly from the basic stored-program architecture and from general purpose computers. They often feature thousands of CPUs, customized high-speed interconnects, and specialized computing hardware. Such designs tend to be useful only for specialized tasks due to the large scale of program organization required to successfully utilize most of the available resources at once. Supercomputers usually see usage in large-scale simulation, graphics rendering, and cryptography applications, as well as with other so-called "embarrassingly parallel" tasks.
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Write down the words into your vocabulary
Heavy multiprocessing, are designed to distribute, once employed, powerful machines, such as, mainframe computers, a single integrated circuit, multi-core, multiple CPU, are now widely available, are being increasingly used, lower-end markets, in particular, significantly, feature, customized high-speed interconnects, tend to be useful, due to, required to successfully utilize, available resources, large-scale simulation, graphics rendering, cryptography applications, embarrassingly.
Agree or disagree with the statements.
- Cray designed a lot of supercomputers that used heavy multiprocessing.
- No computers are designed to distribute their work across several CPUs.
3. A multiprocessing configuration once employedonly in large and powerful machines.
4. Supercomputers differ significantly from general purpose computers with their architecture.
- Supercomputers usually do not see usage in so-called "embarrassingly parallel" tasks.
LESSON 4
I. Match the words.
- May be viewed
- to run a program
- is achieved by multitasking
- cause the computer to stop executing
- to execute a program
- heavy multiprocessing
- powerful machines
- mainframe computers
- a single integrated circuit
- multi-core
- multiple CPU
- customized high-speed interconnects
a. достигается посредством мультизадачности,
b. основанный на высокоскоростном взаимодействии,
c. может рассматриваться,
d. многозадачный ЦПУ,
e. запускать программу,
f. вызывает остановку компьютера,
g. сложная мультиобработка,
h. выполнять программу,
i. универсальные компьютеры,
j. единая схема, мощные машины,
k. многозадачный сердечник,
l. настроенное высокоскоростное взаимодействие.
Module 7
LESSON 1-2
Read and translate the text.
What is a computer virus?
As you see, there are different types of viruses, and they have already been separated into classes and categories. For instance: dangerous, harmless, and very dangerous. No destruction means a harmless one, tricks with system halts means a dangerous one, and finally with a devastating destruction means a very dangerous virus.
But viruses are famous not only for their destructive actions, but also for their special effects, which are almost impossible to classify. Some virus-writers suggest the following: funny, very funny and sad or melancholy (keeps silence and infects). But one should remember that special effects must occur only after a certain number of contaminations. Users should also be given a chance to restrict execution of destructive actions, such as deleting files, formatting hard disks. Thereby virus can be considered to be a useful program, keeping a check on system changes and preventing any surprises such as of deletion of files or wiping out hard disks.
It sounds quite heretical to say such words about viruses, which are usually considered to be a disaster. The less person understands in programming and virology, the greater influence will have on him possibility of being infected with a virus. Thus, let's consider creators of viruses as the best source.
Write down the words into your vocabulary
Have already been separated into, for instance, tricks with system halts, devastating destruction, are almost impossible, suggest, one should remember, occur, a certain number of contaminations, to restrict execution, deleting files, thereby, can be considered to be, disaster, the less…the greater, influence, let's consider.
LESSON 5
Read and translate the text.
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