Differences between processors

	386	386SX	386DX	486	486SX	486DX
386
386SX
386DX
486
486SX
486DX

X. Переведите на английский язык.

1. Для работы с памятью используются две шины – шина адреса и шина данных.

2. Физический адрес передается из процессора в память по шине адреса.

3. Ширина шины адреса определяет максимальный объем физической памяти, непосредственно адресуемой процессором.

4. Логический адрес, или так называемый, виртуальный адрес, состоит из двух 16-разрядных компонент – селектора и смещения.

5. Преобразование виртуального адреса в физический выполняется при помощи таблиц преобразования адресов.

6. Операционная система, использующая реальный режим работы процессора, не защищена от прикладных программ.

4. Прочитайте следующий текст и переведите его без словаря.

General Setup Notes

Make a new startup disk! Because of changes in the real-mode and protect mode kernels to support FAT32, Windows 95 build 950 startup disks m no! compatible with Windows 95 version 4.00.950B startup disks and vice-versa. Therefore, when setting up Windows 95 version 4.00.950B for I he first time, be sure to make a new startup disk. Please do this even if you are not planning to use FAT32.

If you have the Diamond Video "In Control" utility in your StartUp group, you will see the following message: "Some Control Panel or device settings have changed since you last started Windows. Close all of your programs, restart Windows, and then run Setup again." These utilities are installed by some Diamond Stealth display adapter drivers. Remove them from your StartUp group before running Setup.

If you have the Number Nine Imagine 128 Display Adapter, you will probably have to either set up from MS-DOS or change your display driver to VGA to prevent setup from hanging. There is a new 1128 driver in Windows 95 version 4.00.950B. You should use that driver only with Windows 95 version 4.00.950B for now.

If you have a Compaq LTE 5xxx portable, Setup or Installing New Hardware may hang during Hardware Detection when the computer is docked. If this happens, just restart your computer and let Setup Safe

Recovery continue. It will skip over the detection code that hangs, and complete Setup normally. This is due to the way the BIOS works on this computer.

Finding and fixing hard-disk problems during setup (using ScanDisk)

Windows 95 Setup automatically runs ScanDisk to check for problems on you hard disk(s). If there are problems. Setup cannot continue until they are fixed.

Note: The MS-DOS-based version of ScanDisk that Setup runs may detect long filename errors, but it cannot correct them. These errors will not prevent Setup from proceeding, but once it completes, you should run the new Windows version of ScanDisk from within Windows 95 to correct these errors.

Fixing Hard Disk Problems

If you see a message during Setup that says you must run ScanDisk to fix problems on your hard disk. follow these steps to fix the problems. If you are setting up Windows 96 over MS-DOS or a previous version of Windows, such as Windows 3.1:

1. Quit Windows.

2. If you are setting up from floppy disks, insert Setup Disk 1 into the drive, and then type the following at the command prompt:

a:scandisk.exe /all

where "a" is the drive that contains the Windows disk.

If you are setting up from a CD-ROM, insert the CD-ROM and then type the following:

f:\win95\scandisk.exe /all

where "f is the drive that contains the CD-ROM.

3. Follow the instructions on your screen and fix any problems that ScanDisk finds.

4. Start Windows, and then run Setup again.

If you are setting up Windows 95 over a previous version of Windows 95:

1. Quit Setup.

2. On the Start menu, point to Programs, point to Accessories, point to System Tools, and then click ScanDisk.

3. Check your hard disk(s) and any host drives you have for errors, and repair any problems found.

Note: If you are running Setup from MS-DOS, ScanDisk will run and you'll be able to fix most problems from within Setup.

Problems Running ScanDisk

If you get a message during Setup saying that there is not enough memory to run ScanDisk, free some conventional and/or upper memory, and then run Setup again. If you have MS-DOS 6.x, try running MemMaker to free memory. If you still don't have enough memory, or if you have other problems while Setup is running ScanDisk, then you can bypass ScanDisk in Setup by running Setup with the /IS option. To do this, type the following command:

setup /is

Note: Bypassing ScanDisk during Setup is not recommended. If you do, there may be problems with your hard disk that could cause Windows 95 not to install or run correctly. If you still have problems after running Setup with the /IS option, try running Setup with the /IQ option. To do this, type the following command:

setup /is /iq

Unit 8

I. Запомните следующие слова.

intelligent devices интеллектуальные терминалы

data communications средства передачи данных

packet switching коммутация пакетов

suboptimal ниже оптимального

attach подсоединять; прикреплять

remote access дистанционный доступ / выборка

proliferate разрастаться; распространяться

redundant избыточный; резервный

digital data network цифровая информационная сеть

message switch метод переключения сообщений

message store and forward система хранения

system и передачи сообщений

queuing priorities приоритеты массового

обслуживания

implement выполнить; осуществлять,

реализовывать

recognize признавать

drawback недостаток

observe соблюдать

overcome преодолевать

inherent свойственный

conceive понимать; представлять

append присоединять; добавлять

route прокладывать маршруты

chunk часть, программы

faddish причудливый

remedy мера (против)

fullduplex дуплексный

throughput пропускная способность

network switch сетевая коммутация

II. Определите принадлежность слов к частям речи, слова переведите.

assign – assignment

function – functional – functionality

available – availability

technology – technical – technician – technique

address – addressable

origin – originate – original – originally

alternative – alternate – alternatively

compile – recompile – compiler – compilation

compatible – compatibility

translate – translator – translation

automate – automation – automatically

manager – management – manageability

restrict – restriction – restrictive

significant – significance – signify – sign

mean – meaning – meaningful – meaningless

supply – supplement – supplementary

constant – constancy – constantly

III. Переведите предложения, обращая внимание на инфинитивные обороты.

1. He thought all substances to be made up of tiny particles or atoms which could not be further divided.

2. We know the apparatus used for converting electrical energy from one voltage to another to be called a transformer.

3. When water falls a great distance, its energy is known to change from potential to kinetic.

4. The experimental system is said to have worked even better than designers hoped it would.

5. We expected the wire to be coated with a thin layer of pure rubber.

6. He seems to know the subject thoroughly.

7. We know the electrons to flow from the negative terminal of the battery to the positive one.

8. We expected many articles to have already been written on that subject.

9. The current is known to flow when the circuit is closed.

10. Minerals and crystals appear to possess some unexpected properties.

11. He considered the data obtained by the previous authors to be inaccurate.

12. This method is believed to have given good results.

13. The economics of this development program are likely to be highly satisfactory.

14. A decision is known to be modifiable only by changing the value of some of its conditioning variables.

15. These approaches to problems are considered to be good and likely to succeed.

16. There appears to be a great difference between the substances under investigation.

IV. Переведите предложения, обращая внимание на выделенные слова.

1. The student made two experiments; they were both interesting and useful.

2. Both friends study at computer science department.

3. Both of us will work in the institute laboratory tomorrow.

4. Many scientists and inventors, both Russian and foreign, have greatly contributed to the development and practical application of the electric current.

5. The cost of the control system, both in the equipment needed and in staff, is obviously great.

6. There are important differences between the two materials, both in their technology and in their physical properties.

7. An electronic computer can add, subtract, multiply, and divide as well.

8. Natural sciences include mathematics, physics, chemistry, medicine, geology, biology, bionics, as well as the engineering

9. Because of its strongly electropositive character uranium is difficult to reduce to metallic form, and once prepared is difficult to keep pure.

10. As a matter of fact, if the computer is properly designed, the front panel will be the only part of the computer with which the operating personnel will come in contact using the vast majority of the time the computer is being used.

11. The only criterion in this respect is their time relation.

12. Only in this case does the pressure increase.

13. The very package provided an efficient way of transmitting these particles.

14. Because infra-red rays can be detected by their heating effect, they are sometimes referred to as heat waves.

15. Electricity is used in every home in addition to its industrial applications.

16. Uranium is dangerous because of its radioactivity.

17. Rubber is a very poor conductor of electricity.

18. This is the very appliance which I need for my experiment.

I. Прочитайте текст. Придумайте подходящий заголовок к прочитанному тексту. Перечислите все основные факты,

изложенные в тексте, на русском языке. Попробуйте сделать то же самое на английском языке.

Today the data communications field is far different from what it was years ago. Then, data communications was considered as something that occurred primarily between computers and terminals, something that almost always made use of analog telephone circuits with modems at each end. Now the emphasis is on networks which include not only modems and digital transmission facilities, but also intelligent devices for providing services not previously possible. These networks are seen as a medium to which computers, terminals, and other devices connect independently.

Usually the technology mentioned with such networks is packet switching. But there have always been a large number of cases where other networking techniques were more effective, and the rapid rise of microcomputer technology could make packet switching a suboptimal technology for many applications.

To understand why, it is necessary to go back to some basic questions, like: why do we need networks?

There are, and will continue to be, a lot of applications where a pair of modems attached to a transmission facility will adequately satisfy a user's data communications needs. However, the rapid increase in the demand for remote access to data bases and for distributed processing has proliferated the need for more complex structures. The principal needs to be satisfied by a network are:

• alternate resource selection from a single user's equipment;

• shared use of expensive network facilities;

• shared use of redundant facilities to ensure the highest possible service availability;

• centralized management of network elements;

• error-free communication where required;

• compatibility features so dissimilar equipment can communicate.

All of these requirements can be satisfied by digital data networks. All digital switching techniques are based on a very simple principle. A digital switch receives data from a source like a computer or terminal, stores it for some period, and sends it on to a desired destination.

There are three different kinds of digital switches: message switches, packet switches, and time-division circuit switches. The earliest were the message switches. These are often called message store and forward systems.

They include a processor, usually a computer of some sort, and some storage medium. Some have only minicomputer processors and small discs, others are as large as and can act like full-scale general purpose computers.

Message switches take their name from the fact that they store entire message for later delivery to one or more destinations. They deliver their messages on the basis of availability of transmission facilities and of the busy status of the destination terminal. Sometimes queuing priorities are invoked as part of the strategy to determine message delivery times too. In any case, the message destinations arc determined from address fields in the messages themselves, and one or more specific message protocols must be implemented in the terminal equipment for such systems to work.

Message switching technology has found particular use in handling administrative messages within large organizations. However, it was soon recognized that message switching techniques possess major drawbacks for most data communication applications. The main difficulty is that message switches result in far too much delay for interactive applications. Further, the message protocols which must be observed by the user's equipment for message formats and call setup procedures are very restrictive. And since few standards exist, interfacing such networks requires undertaking significant software development.

Thus, modifications to message switching technology were begun which would overcome some of the drawbacks of message switching for data communications. It was recognized that the major difficulties for data communications applications were inherent in message switching technology. The only way one could hope to better the situation was to conceive digital switching techniques which did not require storing entire messages.

The result of this thinking was the emergence of packet switching. In fact, the essence of packet switching is the same as message switching. A block of data from a terminal has addressing information appended so that network switches can route it through a network to its destination. The key difference between message and packet switching is that packet approaches can divide long messages into chunks so that the total transmission delay through a network is shortened. Further, techniques have been developed where addresses are provided by network switches instead of by the user's terminal so that the packet net can be used on a protocol-transparent basis.

Packet switching has been made operational and has become one of the faddish technologies. However, even though packet switching has many benefits, it also has limitations which, like those of message switching, are inherent in the technology. The fact, that data must be dealt, with in

blocks results in undesirable transmission delays which result from one block waiting for another to finish up. The remedies for the delays are primarily the adoption of protocol dependent fullduplex interfaces. But these often result in many of the same complexities faced in trying to apply message switching techniques to data communications.

The third alternative in digital switching is called time-division circuit switching. The essential difference between message and packet switching Oil the one hand and time-division circuit switching on the other is in the size of the blocks of data stored by data switches. In time-division circuit switching, data from a single terminal is stored in very small segments, usually only a single character at a time. The result of this approach can be dramatically smaller network delays in the case of transmission of data from low speed terminals. Even with higher speed terminals there are many instances where time-division circuit switching produces significantly higher throughput than does packet switching.

Since data switches handle only a small segment of data from a single source at one time, it is obvious that the method of signifying the destination of each small data segment must be handled differently in time-division circuit switching than it is in packet or message switching.

2. Прочитайте текст. Найдите в тексте ответы на следующие вопросы.

1. What are essential classes of network products mentioned in the text?

2. What class of networks has future ahead?

3. What does the choice of LAN technology depend on?

4. What network topologies are discussed in the text?

5. What is the essence of bus topology? Has it any drawbacks?

6. What is the essence of token ring topology?

7. What is done to decrease the propagation delay?

8. Is Ethernet a local area network or a global one?

9. What feature defines the propagation delay on an Ethernet?

10. What feature defines the propagation delay on a token ring?

11. What are the limits to physical growth of networks?

12. What is the advantage of Ethernet over token ring?