ical parts, their data access time being longer than is that of electronic memories. 8. For this reason most computer systems use electronic memory for primary storage, electromechanical memory being used for secondary storage. 9. Large capacity tape devices are used with large data processing systems, cassettes and cartridges being applied with small systems. 10. The CPU controls the operation of the entire system, commands being issued to other parts of the system.
7. Ознакомьтесь с терминами текста2.
to manage ['таешёз] — управлять; организовывать;
справляться to obtain [ab'tein] — получать; достигать; добиваться
to cause — заставлять; вынуждать; вызывать; быть причиной; причина, основание
flow ['flou] — поток; ход (выполнения программы); последовательность
counter ['kauntaj — счетчик
register [rred3isto] — регистр; устройство регистрации; счетчик; датчик
instruction register — регистр команд
storage register — регистр памяти; запоминающий регистр
address register — адресный регистр
temporarily [ЧетрэгэпЬ] — временно
decoder [di'kouda] — дешифратор
operand address [ops'raind a'dres] — адрес (хранения) операнда
mark ['mak] — отметка; маркер; знак; помечать; обозначать; выделять
timing mark — отметка времени
accumulate [s'kjimyuleit] — накапливать(ся); суммировать; собирать(ся)
accumulator — сумматор; накапливающий регистр; устройство суммирования
compare [кэт'рсэ] — сравнивать; соотноситься
103 Unit & Central Processing Unit
comparer [кэт'реэгэ] — компаратор; устройство сравнения
content ['kontsnt]— содержимое; смысл; объем; количество
involve [in'volv] — включать; содержать; заключать (в себе)
core ['ka] — суть; основная часть; ядро; оперативная память
add feed] — складывать; суммировать; прибавлять; присоединять
added — добавочный; дополнительный adder — сумматор; блок суммирования at least — по крайней мере
8. Прочтите текст и скажите, о каких компонентах центрального процессора и их назначении вы узнали. Переведите текст.
Text 2. THE CPU MAIN COMPONENTS
As it is known the two functional units of the CPU are the control unit (CU) and the arithmetic-logical unit (ALU). The control unit manages and coordinates the entire computer system. It obtains instructions from the program stored in main memory, interprets the instructions, and issues signals that cause other units of the system to execute them.
The control unit operates by reading one instruction at a time from memory and taking the action called for by each instruction. In this way it controls the flow between the main storage and the arithmetic-logical unit.
The control unit has the following components: a counter that selects the instructions, one at a time, from memory; a register that temporarily holds the instructions read from memory while it is being executed; a decoder that takes the coded instruction and breaks it down into individual commands necessary to carry it out; a clock, which produces marks at regular intervals. These timing marks are electronic and very rapid.
The sequence of control unit operations is as follows. The next instruction to be executed is read out from primary stor-
Английский язык. Основы компьютерной грамотности 104
age into the storage register. The instruction is passed from the storage register to the instruction register. Then the operation part of the instruction is decoded so that the proper arithmetic or logical operation can be performed. The address of the operand is sent from the instruction register to the address register. At last the instruction counter register provides the address register with the address of the next instruction to be executed.
The arithmetic-logical unit (AL U) executes the processing operations called for by the instructions brought from main memory by the control unit. Binary arithmetic, the logical operations and some special functions are performed by the arithmetical-logical unit.
Data enter the ALU and return to main storage through the storage register. The accumulator serving as a register holds the results of processing operations. The results of arithmetic operations are returned to 