Information, machine words, instructions, addresses

When we see number 562 we normally assume that it represents five hundred and sixty-two. This is because we are conditioned to the decimal system where the base is 10. Nowadays school children are taught to handle numbers with different bases such as octal (8) and binary (2). With the number 562 we understand this to mean that we have 5 hundreds, 6 tens and 2 units (5 · 100 + 6 · 10 + 2 · 1) so each digit has a meaning represented by its value and its position.

Computers work by using the binary system where the base is 2. This means that each position can have a value of 0 or 1. So any information may be represented by the binary system including these two digits. Because at their most basic level, computers only understand the language of electricity: positive (or on or 1) and negative (or off or 0). Instead of going up in powers of ten (10,10 x 10,10 x 10 x 10) the positions go up in powers of 2 (2,2 x 2,2 x 2 x 2,2 x 2 x 2, etc.)

Thus the binary number 1001 can be represented as:

2 x 2 x 2s position 2 x 2s position 2s position units position

1 0 0 1

2 x 2 x 2 x 1 = 8 x 1 = 8

2 x 2 x 0 = 4 x 0 = 0

2 x 0 = 0

1 = 1

9

So 1001 in binary has the same value as 9 in decimal.

A group of contiguous bytes that can be manipulated together is called a word. A word may be 2 bytes (16 bits) or 4 bytes (32 bits) or other combinations. 16 bits can hold number up to 65,535. Word length is the term used to describe a word’s size in numbers of bits.

The memory of the computer can hold instructions that the control unit acts upon, and it can store binary numbers on which arithmetical operations can be carried out. A large number of business operations, and computer-based training in particular, do very little with numbers. They are mostly concerned with accepting as input, manipulating and presenting as output, large quantities of character information-names and addresses.

An address is the name of particular memory location or cell. Each memory location (word or byte) has it own unique address or number just a post office box. If one character is stored in a byte, there are 256 possible characters that the different bit patterns can represent. That is quite adequate for all alphabetic characters in upper and lower case, the number 0 to 9 and the various punctuation and special characters that are found on a typewriter keyboard. One widely used Coding convention is ASCII (American Standard Code for Information Interchange), pronounced as the two words «ass» and «key».

This is a part of the ASCII Code

Сharacter % E+ ‘ ( ) * + , - . /

ASCII Code 37 38 39 40 42 43 44 45 46 47
Сharacter 0 1 2 3 4 5 6 7 8 9

ASCII Code 48 49 50 51 52 53 54 55 56 57

ASCII Code 65 66 67 68 69 70 71 72 73 74

Thus, if we wanted to hold FRANKLIN in part of the correct answer it could be held somewhere in memory (say location 5390 onwards) as the following ASCII codes:

Letter F R A N K L I N

Code in memory 70 82 65 78 75 76 73 78

Memory location 5390 5391 5392 5393 5394 5395 5396 5397

Computer people generally refer to 1000 (1024 to be precise) byte as a kilobyte (kb) and a million bytes as a megabyte (mb). So, if somebody has a microcomputer with 640 k memory locations than means there are 640,000 locations in the machine.

Reasonable operations are mathematical and logical. Mathematical operations include arithmetical and algebraic operations. Arithmetical operations are addition, subtraction, multiplication, division, taking a square root, etc.; and algebraic operations are called raising to a power as well as differentiating and integrating.

Logical operations include comparing, selecting, sorting, matching, etc.

III. Translate these into your own language:

1. a set of marks and signs 7. bytes

2. circular beginning and ending with people 8. bits are grouped

3. we are conditioned to the decimal system 9. can be manipulated together

4. base 10. to hold instructions

5. including these two digits 11. memory location

6. the positions go up in powers of 2 12. to include

IV. Translate these into English:

1. множество знаков 7. десятичное число

2. число представляет 8. запоминать, хранить в памяти

3. учат работать с числами 9. выполнять

4. у каждого есть свое значение 10. точно

5. двоичная система исчисления 11. разумные операции

6. основной уровень


V. Fill in the necessary words:

1. ..... is a set of marks or signs.

2. We are conditioned to the ..... ..... .

3. Computers work by using the ..... ..... where the ..... is 2.

4. The ..... of a computer consists of a large number of locations.

5. A ..... is the smallest part of information.

6. A byte consists of 8 ..... .

7. The memory of the computer can ..... instructions.

8. Computer people generally ..... ..... 1 000 bytes as a kilobyte.

VI. Fill in the prepositions:

1. Nowadays school children are taught to handle numbers ..... different bases.

2. ..... their most basic level, computers only understand the language of electricity.

3. Instead of going ..... in powers of ten, the positions go ..... ..... powers of 2.

4. Each position can be set ..... 0 or 1.

5. Bits are grouped ..... units.

6. The memory can store binary numbers ..... which arithmetical operations can be carried ..... .

VII. Give the correct definitions of the following terms:

a) information c) bit e) word g) reasonable operation

b) binary system d) byte f) address

VIII. Answer the following questions:

1. What is information?

2. Do computers work by using binary or decimal system?

3. What is the base of the binary system?

4. How can any information be represented?

5. What is the ASC II Code?

regardless независимо

to monitor to fit

to enter a hardware representative

a routing peripheral available

to direct a variety to purchase

a property an occurrence a competitor

to modify to afford incredibly

solely to confine to convince


II. Read the text and do the exercises that follow it.