Unit 3

Text Study: Memory.

Additional Text: "Cache" Memories.

Grammar: The Future Perfect Tense.

Text Study

I. Pre-reading Exercises

1. Repeat the words in chorus:

Storage, internal, ongoing, a semiconductor, available,  ROM – Read Only Memory, RAM - Read Write Memory, the acronym, to distinguish, to  access, sequential, substantial, quoted, to require, mercury, a "flip-flop", to elaborate, available.

2. While reading the text you will come across a number of international words. Try to guess what Ukrainian words they remind of you:

Normal, the acronym, an origin, minimal, machines, graphics, displays, byte, bit, popular, technology, magnetic, a disk, gigabyte.

3. Pay attention to some grammatical points:

1) There are primary and secondary storage units. 2) Data as well as instructions must flow into and out of primary storage. 3) Therefore slower, less ex­pensive storage units are available for computer systems. 4) These units are called secondary storage. 5) Data are stored in them in the same binary codes as in main storage and are made avail­able to main storage as needed. 6) It was used to distinguish main memory from secondary storage like tapes. 7) Many different technologies have been used. 8) Repeated again and again, these can be built up into integrated circuits that hold millions of bytes. 9) Individual memory chips with as much as 4 million bytes of storage capacity can now be purchased.

II. Reading

Read the text and be ready to find in the text the answers to the following questions:

·         What is the main function of primary storage?

·         What are two types of computer memory?

Memory

There are primary and secondary storage units. Both contain data and the instructions for processing the data. Data as well as instructions must flow into and out of primary storage.

Primary storage is also called main storage or internal storage. The specific functions of internal storage are to hold (store): 1) all data to be processed; 2) intermediate results of process­ing; 3) final results of processing; 4) all the instructions required for ongoing process.

Primary storage is expensive because each bit is represented by a high-speed device, such as a semiconductor. A million bytes (that is, 8 million bits) is a large amount of primary storage. Often it is necessary to store many millions, sometimes billions, of bytes of data. Therefore slower, less ex­pensive storage units are available for computer systems. These units are called secondary storage. Data are stored in them in the same binary codes as in main storage and are made avail­able to main storage as needed.

Computers have two types of memory: ROM – Read Only Memory, RAM - normal Read Write Memory. The acronym RAM instead of RWM is standard. It actually standards for "Random Access Memory". Its origin is very old, it was used to distinguish main memory (where data values can be accessed in any order – hence "randomly") from secondary storage like tapes (where data can only be accessed in sequential order). ROM memory is generally used to hold parts of the code of the computer's operating system. Some computers have small ROM memories that contain only a minimal amount of code just sufficient to load the operating system from a disk storage unit. Other machines have larger ROM memories that store substantial parts of the operating system code along with other code, such as code for generating graphics displays.

Most of the memory on a computer will be RAM. RAM memory is used to hold the rest of the code and data for the operating system, and the code and data for the program(s) being run on the computer.

Memory sizes may be quoted in bits, bytes, or words:

Bit        a single 0 or 1 data value

Byte     a group of 8 bits

Word   the width of the primary data paths between memory and the CPU,   maybe 16-bit (two byte), 32-bit (four byte) or larger.

Memory sizes are most commonly given in terms of bytes. (The other units are less useful for comparative purposes. Bits are too small a unit of storage. Word sizes vary between machines and on some machines aren't really defined.) The larger memory units like bytes and words are just made up from groups of bits.

All storage devices require simple two-state components to store individual bits. Many different technologies have been used. Some early computers distinguished 0 and 1 bit values by the presence or absence of a pulse of energy moving through a tube of mercury; external storage was provided using paper media like cards or tapes where the presence or absence of a punched hole distinguished the 0/1 bit setting. Later, the most popular technology for a computer's main memory used small loops of magnetic oxide ("cores") that could be set with differing North/South polarity to distinguish the 0/1 bit state. Disks (and tapes) still use magnetic encoding – 0/1 bit values are distinguished by the magnetic state of spots of oxide on the disk's surface. The main memories of modern computers are made from integrated circuits.

One basic circuit is a "flip-flop". This uses four transistors wired together; it can be set in an on or an off state and so can hold one bit. A more elaborate circuit, with eight flip-flops, can hold one byte. Repeated again and again, these can be built up into integrated circuits that hold millions of bytes. Individual memory chips with as much as 4 million bytes of storage capacity can now be purchased. A computer's memory will be made up out of several of these chips.

The amount of memory available on a computer has increased rapidly over the last few years. Most current personal computers now have around 8 million bytes of storage (8 megabyte, 8MB); more powerful workstations have from 32MB to 256MB and large time shared systems may have 1000 MB (or 1gigabyte).

Vocabulary Notes

to flow – витікати, виходити з

primary storage / internal storage – первинний запам’ятовуючий пристрій

intermediate ["IntW'mJdjqt] – проміжний, середній

a semiconductor – напівпровідник

available [q'veIlqbl] – доступний, наявний, корисний

to distinguish [dIs'tINgwIS] – відрізняти, розглядати

sequential [sI'kwenSlql] – послідовний 

to load – грузити, загружати, вміщувати

an external storage – зовнішній запам’ятовуючий пристрій, зовнішня пам’ять

a surface ['sWfIs] – поверхня, зовнішність

an integrated circuit – інтегрована схема

an elaborate circuit – добре продумана схема

to purchase ['pWtSqs]– купувати  

to share – ділитися, поділяти

"flip-flop"– тригер, тригерна схема

mercury ['mWkjurI]– ртуть, ртутний стовп

punched hole – перфораційний отвір

a loop – петля, цикл програми

Comprehension

1. Tell what sentences are true and what are false.

1) There are primary and secondary storage units which contain data and the instructions for processing the data. 2) Primary storage is also called main storage or secondary storage. 3) Primary storage is cheap because each bit is represented by a low-speed device. 4) Slower, less ex­pensive storage units are called secondary storage. 5) Data are stored in secondary storage in the same binary codes as in main storage. 6) Computers have three types of memory. The acronym RAM is Random Access Memory. 7) Its origin is not very old, it was used to distinguish main memory from secondary storage like tapes. 8) ROM memory is generally used to hold parts of the code of the computer's operating system. 9) Memory sizes are most commonly given in terms of bits. 10) The main memories of modern computers are made from integrated circuits.

2. Choose the right answer:

1) Primary and secondary storage units contain … .

a) data and the instructions for processing the data;

b) the instructions for processing the data;

c) only data.

2) The specific functions of internal storage are to hold: … .

a) all data and the instructions;

b) intermediate and final results of processing;

c) all data, intermediate results, final results of processing and the instructions.

3) ROM memory is generally used … parts of the code of the computer's operating system.

a) to drop;

b) to hold;

c) to show.

4) …  are too small a unit of storage.

a) bits;

b) bytes;

c) megabyte.

5) One basic circuit is … .

a) complex;

b) integrated;

c) a "flip-flop".

3. Complete the sentences:

1) Primary and secondary storage units contain … and … . 2) Primary storage is also called … .  3) The specific functions of internal storage are to hold (store): … . 4) A million bytes (that is, 8 million bits) is … . 5) Secondary storage is … . 6) Computers have two types of memory … . 7) Most of the memory on a computer will be … .  8) RAM memory is used to … . 9) All storage devices require … . 10)  The main memories of modern computers are made from … . 11) Most current personal computers now have around … million bytes of storage. 

4. Answer the questions:

1) What does primary storage hold? 2) What is secondary storage? 3) What are types of memory? 4)  Why is primary storage expensive? 5)  What was "Random Access Memory" used to? 6) What was ROM used to? 7) Are memory sizes most commonly given in terms of bytes? Why? 8) What do all storage devices require? 9) What are the main memories of modern computers made from? 10) What is most current personal computers?

5. Find as quickly as possible and read out the sentences containing the following important information:

• primary storage
• two types of memory
• all storage devices

*6. Try to tell the gist of the text.

Word Study

1. Give Ukrainian equivalents of the following.

Primary and secondary storage unit, to contain data and the instructions,  processing the data,  to flow into and out of primary storage unit, intermediate results,  the instructions required,  a high-speed device, available for computer,  to be accessed, in sequential order, to load from a disk,  to store substantial parts,  memory sizes,  a tube of mercury, a punched hole,  magnetic oxide,  the disk's surface, integrated circuits, current personal computers.

2. Give English equivalents of the following.

        Включати інформацію і команди, входити і виходити з первинного запам’ятовуючого пристрою, первинний і вторинний запам’ятовуючі пристрої, сучасний персональний комп’ютер, проміжні результати, високошвидкісний пристрій, доступний для комп’ютера, оброблення даних, необхідні команди, бути доступним, послідовно, зберігати основні частини, загрузити з диска, трубка з ртуттю, розмір пам’яті, магнітний оксид, поверхня диска, інтегровані схеми, перфораційний отвір.

3.  Match the words in A with their synonyms in B:

A                                 B

to flow                        useful

available                     to stream

to distinguish               to fill  

to load                         modern

a surface                     to recognize

to purchase                 appearance

current                        to buy

4. Fill in the gaps with the words from Vocabulary Notes in the appropriate form.

to flow / a semiconductor / integrated circuits / primary and secondary / memory / ROM / RAM / available / to require / to distinguish

1) … storage units contain data and the instructions for processing the data. 2) Data as well as instructions must … into and out of primary storage. 3) Each bit of a primary storage is represented by a high-speed device: … . 4)  Secondary storage is slower, less ex­pensive unit which is … for computer systems. 5) Some computers have small … memories that contain only a minimal amount of code. 6) Most of the memory on a computer will be … . 7) All storage devices … simple two-state components to store individual bits. 8)  Some early computers … 0 and 1 bit values by the presence or absence of a pulse of energy moving through a tube of mercury. 9) The main memories of modern computers are made from … . 10) The amount of … available on a computer has increased rapidly over the last few years.

5. Translate sentences into English using words and word combinations from the Vocabulary Notes.

1) Первинний і вторинний запам’ятовуючі пристрої включають в себе інформацію та інструкції для обробки цієї інформації. 2) Основною функцією первинної пам’яті є утримувати всю оброблювальну інформацію, проміжні і кінцеві результати і команди. 3) Первинна пам’ять – дорога, а вторинна – дешевша. 4) Комп’ютер має два види пам’яті. 5) Основна пам’ять сучасних комп’ютерів складається з інтегрованих схем. 6) Комп’ютерна пам’ять складається з кількох чіпів.

The Grammar in Use

The Future Perfect Tense

1. Turn the following into the Future Perfect.

1) Railway companies had used large computer systems to control ticket reservations by the first of September. 2) A railway’s computer system had got thousands of telephone calls about reservations, space on other railways, and requests for arrivals and departures by 2 p.m. 3) The computer memory had contained all kinds of information by the end of the next day. 4) Computers had certainly revolutionized police work by the end of the month. 5) Almost every medium-sized or large company had used computers to help run the office by that time. 6) You had used a computer in your day - to-day duties by the day of your wedding. 7) A computer really had made office life easier by that year.

2. Replace the infinitive in brackets by the Future Indefinite or the Future Perfect.

1) I (to download) all the information I can find on the Internet about this subject tomorrow. 2) I (to find) the problem by that time tomorrow. 3) I (to type) the password and (to open) the file by midnight, I think. 4)  The new version of this software (to appear) in July. 5) We (to dump) all the information onto the hard disk of the server by that time. 6) We (to search) the database next week. 7) We (to place) all the machines on the fourth floor by 3 p.m. 8) With this system we (to eliminate) all possibilities of error tomorrow.

3. Put questions to the underlined words.

1) This system will have been easy to install by 2 p.m. tomorrow. 2) The system will have failed by the morning. 3) Jack will have been responsible for maintaining the system by the midday. 4) You will have finished typing before I see you. 5) I will have forgotten the extreme game by the next morning. 6) The students will have finished their thesis by the end of April.

Additional Text

(for individual work)

Read and translate the text.

"Cache" Memories

"Cache" memories are increasingly common ("cache – a hiding place for provisions, treasures etc"). Cache memories are essentially hidden from the applications programmer; the cache belongs to the computer hardware and its controlling operating system. These work together using a cache to increase performance. Currently, a typical cache memory would be up to 256 KB in size. The cache may form a part of the circuitry of the CPU chip itself, or may be a separate chip. Either way, the system will be designed so that information in the cache can be accessed much more quickly than information in main storage.

The OS and CPU hardware arrange to copy blocks of bytes ("pages") from main memory into the cache. The selected pages could be those with the instructions currently being executed. Most programs involve loops where particular sets of instructions are executed repeatedly. If the instructions forming a loop are in the cache, the CPU's instruction-fetch operation is greatly speeded up. Sometimes it is worth copying pages with data from main memory to the cache – then subsequent data accesses are faster (though data that get changed do have to be copied back to main memory eventually). The operations shifting pages, or individual data elements, between cache and memory are entirely the concern of the CPU hardware and the operating system. The only way that a programmer should be able to detect a cache is by noticing increased system's performance.

All data manipulated by computers are represented by bit patterns. A byte, with 8 individual bits, can represent any of 256 different patterns.

1. Divide the text into the logical parts and give a title to each one.

2. Put questions to the text.

3. Discuss it with your groupmates.