Glossary

ALU (arithmetic logic unit) – арифметико-логическое устройство

BIOS (basic input/output system) – базовая система ввода/вывода

binary number – двоичное число

blur the distinction – стирать различие

cache memory – кэш (быстродействующая буферная память не-

большой емкости)

CPU (central processing unit) – центральный процессор

consecutive – последовательный, непрерывно следующий друг за

другом

conventional – зд. обычный

erase – стирать, уничтожать

firmware – встроенное программное обеспечение

flash memory – флеш-память (память с групповой перезаписью)

notionally – теоретически

RAM (random-access memory) – оперативная память, оперативное

запоминающее устройство

ROM (read-only memory) – постоянное запоминающее устройство

retain – сохранять, удерживать

two’s complement notation – запись (система обозначений), пред-

ставленная в дополнительном коде

Text b. Computer Data Storage

A computer's memory can be viewed as a list of cells into which numbers

can be placed or read. Each cell has a numbered "address" and can store a single

number. The computer can 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 can be placed into memory with equal ease. Since the CPU

does not differentiate between different types of information, it is the software's

responsibility to give significance to what the memory sees as nothing

but a series of numbers.

In almost all modern computers, each memory cell is set up to store binary

numbers in groups of eight bits (called a byte). Each byte is able to

represent 256 different numbers (2^8 = 256); 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 can store any kind of information in memory if it can be represented

numerically. 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 to 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. As 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.

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, but

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 required software may be stored in ROM. Software 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, as it retains its data

when turned off but is also rewritable. It is typically much slower than conventional ROM and RAM however, so its use is restricted to applications where high speed is unnecessary.

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.

Exercise 4. What do the following abbreviations stand for? They are all used in the article:

PC CPU ALU RAM ROM BIOS

Exercise 5. Find the words in the article which mean the following. The first and the last letters are given:

1) describes events, numbers, etc. that follow one after another without

an interruption (paragraph 2) c…e

2) to remove something (paragraph 4) e … e

3) to arrange something carefully (paragraph 4) o … e

4) a set of instructions which form part of an electronic device and

which allow it to communicate with a computer or with other electronic

devices (paragraph 4) f … e

5) to intentionally become involved in a difficult situation in order to improve

it or prevent it from getting worse (paragraph 5) i … n

Exercise 6. Answer the following questions:

1) How can computer data storage be defined?

2) How does computer memory work (operate)?

3) What can significantly increase the computer’s speed?

4) What is the difference between RAM and ROM?

5) When is flash memory used?

Glossary

ALU (Arithmetic and Logic Unit) – арифметико-логическое устройство

blueprint – детальный план, программа; шаблон, образец

cache – кэш, сверхоперативная память

cluster computing – объединение (группа) компьютеров

computer architecture – архитектура компьютера [вычислитель-

ной системы], организационная структура компьютера [вычис-

лительной системы], включающая потоки и представление дан-

ных, интерфейсы, набор команд, способы адресации, регистры,

аппаратное и программное обеспечение. Термин введён корпора-

цией IBM при создании семейства совместимых ЭВМ System/360

computer buses – компьютерные шины

computer engineering – компьютерная инженерия

conceptual – понятийный, концептуальный, абстрактный

CPU (central processing unit)– центральный процессор

design engineering – инженерное проектирование

direct memory access – прямой доступ к памяти

gate level – на вентильном уровне

implementation – реализация, внедрение

ISA (instruction set architecture) – архитектура набора команд

latch – задвижка

machine (assembly) language – машинный язык (ассемблер)

memory address modes – адрес ячейки памяти

memory controllers – контроллеры памяти

multiplexer – многоканальный модулятор

Multiprocessing – многопроцессорная обработка; параллельная об-

работка

NUMA (Non-Uniform Memory Access or Non-Uniform Memory Architecture)

– технология доступа к неоднородной памяти

processor register – регистр процессора

specify – точно определять, устанавливать