Задание 3. Прочитайте текст и обсудите следующие вопросы в группе.

a) What is a microprocessor? Try to give your own definition of this term.

b) What is a microcomputer based on?

Task  4. Complete the gaps in this dialogue with will or would or the reduced forms ’II and У where appropriate. A – first student, B – second student

A) What…..you do when you finish your diploma?

B) ……like to take a course in multimedia.

A) How long…..that take?

B) If I choose the certificate, it….. take 6 months but if i………

A) What…..be the advantage of the master’s?

B) I guess…..have better job prospects.

A) When…..you decide?

B) It depends on my finals. If I do well, i…..go for the master’s.

Task  5. Link each word in column A with a word which it often occurs with from column B. In some cases, more than one link is possible.

A – bulletin, domain, file, graphical, mobile, search, site, synchronous, text, web.

B – board, button, engine, link, map, message, name, page, phone, transmission.

LESSON 24

What is a Microprocessor?

Task 1. Read and translate the text:

Задание 1. Прочитайте и переведите текст

Part II

A microprocessor is the central arithmetic and logic unit of a computer, together with its associated circuitry, scaled down so that it fits on a single silicon chip (sometimes several chips) holding tens of thousands of transistors, resistors and similar circuit elements. It is a member of the family of large-scale integrated circuits that reflect the present state of evolution of a miniaturization process that began with the development of the transistor in the late 1940's. A typical microprocessor chip measures half a centimeter on a side. By adding anywhere from 10 to 80 chips to provide timing, program memory, random-access memory, interfaces for input and output signals and other ancillary functions, one can assemble a complete computer system on a board whose area does not exceed the size of this page. Such an assembly is a microcomputer, in which the microprocessor serves as the master component. The number of applications for microprocessors is proliferating daily in industry, in banking, in power generation and distribution, in telecommunications and in scores of consumer products, ranging from automobiles to electronic games. As in the central processing unit, or CPU, of a larger computer, the task of the microprocessor is to receive data in the form of strings of binary digits (O's and 1's), to store the data for later processing, to perform arithmetic and logic operations on the data in accordance with previously stored instructions and to deliver the results to the user through an output mechanism such as an electric typewriter, a cathode-ray-tube display or a two-dimensional plotter. A typical microprocessor would consist of the following units: a decode and control unit (to interpret instructions from the stored program),

the arithmetic and logic unit, or ALL) (to perform arithmetic and logic operations), registers (to serve as an easily accessible memory for data frequently manipulated), an accumulator (a special register closely associated with the ALL)), address buffers (to supply the control memory with the address from which to fetch the next instruction) and input-output buffers (to read instructions or data into the microprocessor or to send them out). Present microprocessors vary in their detailed architecture depending on their manufacture and in some cases on the particular semiconductor technology adopted. One of the major distinctions is whether all the elements of the microprocessor are divided among several identical modular chips that can be linked in parallel, the total number of chips depending on the length of the "word" the user wants to process: four bits (binary digits), eight bits, 16 bits or more. Such a multichip arrangement is known as a bit-sliced organization. A feature of bit-sliced chips made by the bipolar technology is that they are

"microprogrammable": they allow the user to create specific sets of instructions, a definite advantage for many applications.

Task  2. Answer the following questions:

Задание 2. Ответьте на следующие вопросы:

1. Read the second part of the text ‘What is a Microprocessor’?

2. Study the definition of terms given below the text.

Task  3. Discuss the following questions in group:

a) Find in the text the definition of a microprocessor. What kind of new information has been added to its content?

b) What is the history of the invention of this logic device?

c) What is the function of the microprocessor?

d) What does a typical microprocessor consist of?

e) What is the feature of bit-sliced chips made by the bipolar technology?

f) How are modern microprocessors differentiated?

Task  4. Find the answers to these questions in the following text.

1. Name three different email protocols mentioned in the text.

2. Which email protocol is used to transfer messages between server computers?

3. Why is SMTP unsuitable for delivering messages to desktop PCs?

4. Name two host-based mail systems mentioned in the text.

5. Where are email messages stored in an SMTP system?

6. What happens when you use your Web mail account to access a POP3 mailbox?

7. Give an advantage and a disadvantage of having an option to leave POP3 messages on the server.

8. What are the advantages of using the IMAP4 protocol?

Email Protocols!

Although the format of a mail message, as transmitted from one machine to another, is rigidly defined, different mail protocols transfer I and store messages in slightly different ways. The mail system you’re probably used to employs a combination of SMTP and POP3 to send and receive mail respectively. Others may use IMAP4 to retrieve mail, especially where bandwidth is limited or expensive.

Simple MailTransferProtocol.

SMTP is used to transfer messages between one mail server and another. It's also used by email programs on PCs to send mail to the server. SMTP is very straightforward, providing only facilities to is deliver messages to one or more recipients in batch mode. Once a message has been delivered, it can’t be recalled or cancelled. It’s also deleted from the sending server once it’s been delivered. SMTP uses ’push’ operation, meaning that the connection is initiated by the sending server rather than the receiver. This makes it unsuitable for delivering messages to desktop PCs, which aren't guaranteed to be switched on at all times. In host-based mail systems, such as Unix and Web. SMTP is the only protocol the server uses. Received messages are stored locally and retrieved from the local file system by the mail program. In the case of Web mail, the message is then translated into HTML and transmitted to your so browser. SMTP is the only protocol for transferring messages between servers. How they're then stored varies from system to system.

Post Office Protocol.

POP is a message-retrieval protocol used by many PC mail clients to get messages from a server, typically your ISP's mail server. It only allows you to download all messages in your mailbox at once. It works in 'puli' mode, the receiving PC initiating the connection. PC-based POP3 mail clients can do this automatically at a preset interval. When you use your Web mail account to access a POP3 mailbox, the mail server opens a connection to the POP3 server just as a PC-based application would.The messages are then copied into your Web mailbox and read via a browser.

Since POP3 downloads all the messages in your mailbox, there's an option to leave messages on the server, so that they can be picked up from different machines without losing any. This does so mean that you'll get every message downloaded every time you connect to the server. If you don't clean out your mailbox regularly, this could mean long downloads. When using a Web mail account to retrieve POP3 mail, be careful about leaving messages on the server if too many build up, each download will take a long time and fill up your inbox. Many Web mail systems won't recognise messages you've already downloaded, so you'll get duplicates of ones you haven't deleted.

 Internet Mail Access Protocol.

IMAP is similar in operation to POP, but allows you more choice over what messages you download. Initially, only message headers are retrieved, giving information about the sender and subject. You can then download just those messages you want to read. You can also delete individual messages from the server, and some IMAP4 servers let you organise your mail into folders. This makes download times shorter and there's no danger of losing messages.

Task  5. Mark the following statements as True or False:

1. Different mail systems transfer emails in different ways.

2. IMAP4 requires more bandwidth than the other email protocols.

3. SMTP is used for sending emails from a PC to a server.

4. SMTP delivers messages one at a time.

5. SMTP does not allow a delivered message to be cancelled.

6. SMTP is only one of many protocols used to send mail between servers.

7.POP protocol allows the user to download one message at a time.

LESSON 25