Bits and bytes

Computers do all calculations using a code made of just two numbers – 0 and 1. This system is called binary code. The electronic circuits in a digit computer detect the difference between two states: ON (the current passes through) or OFF (the current doesn’t pass through) and represent these states as 1 or 0. Each 1 or 0 is called a binary digit, or bit.

Bits are grouped into eight-digit codes that typically represent characters (letters, numbers and symbols). Eight bits together are called a byte. Thus, each character on a keyboard has its own arrangement of eight bits. For example, 01000001 for the letter A, 01000010 for B, and 01000011 for C.

Computers use a standard code for the binary representation of characters. This is the American Standard Code for information Interchange, or ASCII – pronounced [‘æski]. In order to avoid complex calculations of bytes, we use bigger units such as kilobytes, megabytes and gigabytes.

We use these units to describe the RAM memory, the storage capacity of disks and the size of a program or document.

Note: bit is pronounced [bit]; byte is pronounced [bait]

Unit of memory	Abbreviation	Value (Decimal)	Value (Binary)	Exact memory amount
Binary digit	Bit, b	1 or 0		1 or 0
Byte	B			8 bits
Kilobyte	KB or K	1000	1024	1,024 bytes (210)
Megabyte	MB	10002	10242	1,024 kilobytes (220)
Gigabyte	GB	10003	10243	1,024 megabytes (230)
Terabyte	TB	10004	10244	1,024 gigabytes (240)
Petabyte	PB	10005	10245	1,024 Terabytes (250)
Exabyte	EB	10006	10246	1,024 Petabytes (260)
Zettabyte	ZB	10007	10247	1,024 Exabytes (270)
Yottabyte	YB	10008	10248	1,024 Zettabytes (280)

A bit is the smallest unit in a computer’s memory.

A binary code represents text or computer processor instructions using the binary number system's two binary digits, 0 and 1. A binary code assigns a bit string to each symbol or instruction.

B. Fill in the spaces using the words from the text.

1. A … is about one trillion bytes – about as much text as the books and magazines in a huge library.

2. A … is about one million bytes about as much text as a 300 page novel.

3. A …. .is about one thousand bytes – equivalent to one sheet of A4.

4. A …..is about one billion bytes – about as much text as 1,000 books.

5. A ….can store a single character as the letter N or number.

Unit 3 Peripherals

Remember the following words and word combinations.

1. separate, v – отделять, разделять

2. controller – контроллер устройства

3. wide array – огромное количество

4. dongle – защитная заглушка, электронный защитный ключ, электронное устройство защиты

5. protect, v – защищать

6. enter, v – вносить, вводить

7. interpret, v – истолковывать, интерпретировать

8. layout – раскладка клавиатуры, размещение

9. navigate, v – передвигаться

10. to interact – взаимодействовать

11. touchpad – сенсорная панель

12. touchscreen – сенсорный экран

13. rectangular - прямоугольный

14. pointer – указатель, стрелка

15. drag, v – перемещать, тянуть

16. surface – поверхность

17. image – изображение

18. transfer, v – передавать, переносить

19. electrical current – электрический ток

Read and translate the text.