Presentation on the topic "Encoding of text (symbolic) information". Presentation on informatics on the topic "coding of text information" Download presentation coding and processing of text information
Coding and Processing of Textual Information Chapter II
2. Coding and processing of textual information 1.Coding of textual informationCoding of textual information 2.Creating and editing documentsCreating and editing documents 3.Formatting a documentFormatting a document 4.TablesTables 5.Computer dictionaries and machine translation systems Computer dictionaries and machine translation systems 6.Optical systems Document Recognition Systems
Encoding text information
Textual information Textual information - information expressed using natural and formal languages in writing The text consists of: letters (uppercase and lowercase letters of the Russian and English alphabets) numbers (1, 2,… 9) characters? #% ^ &.) math symbols (+ - * / =) 4
Binary coding of text information To encode each character, 8 bits of information are required (N = 2 8 N = 256) Each character corresponds to a unique binary code from the interval from to (in decimal code from 0 to 255) 6
Code table Codes from 0 to 32 - correspond to operations (line feed, space entry, etc.) Codes from 33 to 127 - international, correspond to Latin characters, numbers, punctuation marks and arithmetic operations Codes from 128 to 255 - national, those. in different national encodings different characters correspond to the same code 7
Unicode is a new international standard for coding text characters, which allocates 2 bytes (16 bits) for each character. According to this standard, you can encode characters (N = 2 16 N =) The Unicode table includes Russian and Latin alphabets, numbers, signs and mathematical symbols, Greek, Arabic, Hebrew and other alphabets 10
Jobs In text mode, the computer monitor screen is typically split into 25 lines of 80 characters per line. Determine the amount of text information that occupies the entire screen of the monitor, encoded in Unicode 2. A computer user who is good at entering information from the keyboard can enter 100 characters per minute. How much information can a user enter in one minute in Windows encoding? Unicode encoding? eleven
Practical work 2.1. "Encoding Russian letters" To complete the task, use: OpenOffice Writer Program Calculator Save the file in your folder under the name "Encoding Russian letters" 12 Unicode encoding (hexadecimal code) Decimal system Task: fill in the table
13
1.How much memory will the text below take if it is known to use the ASCII encoding table? Happy New Year, dear friends! 2. How many characters are there in an ASCII text if it is known to take up a bit of memory? Task 2.2 Task for repetition Encoding text information 14
Creating and editing documents
1.Simple text editors - allow you to edit text and format the font (Notepad); 2. Word processors - allow you to insert lists and tables, formulas, check spelling, work with graphics (MS Word, OpenOffice Writer); Text editor types: 18
3. Desktop publishing systems - powerful word processing programs that allow you to create layouts for books, magazines and newspapers (Microsoft Publisher, Adobe PageMaker); 4. Web editors - used to prepare Web pages and Web sites (Microsoft Publisher, Microsoft FrontPage) for publication on the Internet. 20 Types of text editors:
Ways of creating documents in text editors 1. With the help of the Wizard - to create documents with a complex structure (letters, resumes, faxes, calendars, etc.); the development of a document using the wizard is carried out by entering the necessary data into the sequentially appearing dialog panels. 22
Page parameters 1. Page format - determines its size: A3 (42 × 29.7 cm) - for announcements, posters; A4 (21 × 29.7 cm) - for abstracts, letters, statements; A5 (21 × 14.8 cm) - for information, etc. 2. Page orientation - sets the position of the text and the appearance of the page on the monitor screen: portrait orientation - for ordinary texts; landscape orientation - for tables with many columns. 3.Bargins - determine the distance from the edges of the page to the borders of the text 25
Text document formats .txt - universal text format, files have a small information volume and can be read by various applications, text formatting is not saved; .rtf - universal extended text format, formatting results are saved, large information volume of files; thirty
1.Use the wizard to create a calendar for the next month. 2.Use the Template to create your resume. 3.Save the created documents in your folder Text Documents Performed in MS Word 33 Practical homework is optional for an additional mark
Reference information Key assignment: Keyboard shortcut Purpose Enter Enter a command, move the blinking cursor to a new line. Shift Allows you to print uppercase characters and uppercase (uppercase) letters. Delete Deletes the selected object; deletes characters to the right of the blinking cursor. (Backspace) Deletes characters to the left of the blinking cursor. Esc Cancel commands, exit the program. Caps Lock Switch to caps mode. Ctrl + Alt + Delete Wakes the computer out of the freeze state. Num Lock Enables the right numeric keypad. Shift + Alt Switch the keyboard to another language. Shift + Ctrl Switch the keyboard to another language. 34
Reference information Fragment selection: 1. Arbitrary text fragment - put the mouse pointer at the beginning of the fragment and, with the LC pressed, move it along the text, highlighting letter by letter; 2. one word - 2 LC per word; 3. one offer - 1 LC for the offer while holding down the Ctrl key; 4. one line - 1 LC in the selection bar opposite the desired line (on the left margin of the document, the type of the mouse pointer -); 5. paragraph - 2 LCs in the selection bar; 6. whole document - 1 LC in the selection bar with the Ctrl key pressed; 7.Vertical text fragment - with the LC pressed and the Alt key pressed, move the mouse pointer down and to the right. 35
Task: Create a text file and insert a formula into it Save the file in your folder in odt format, under the name: "Inserting formulas into a document" Detailed recommendations for implementation on the next slide 36 Practical work 2.2. "Inserting Formulas into a Document"
37
Document formatting
STRUCTURAL UNITS OF TEXT Text editor environment Text typed by the user on the keyboard is displayed in the working area of the editor on the screen. The place of influence on the working field is marked with the cursor. The cursor looks like a blinking dash or rectangle. Often the text is larger than what can fit on the screen. In this case, only part of the text is located within the working area. The screen is a kind of window through which you can view the text. To move through the text, special keyboard keys or scroll bars in the document window Briefly about the main text editor (TP) is an application designed for creating and editing text documents, viewing document content on the screen, changing the document format, printing text on paper using printer. The standard components of the TP environment are: a working field, a text cursor, a status bar, a command menu, a markup ruler, a scroll bar. symbol word line paragraph section page 40
Font A font is a complete set of symbols for a specific drawing: - font name (Times New Roman, Arial, Courier New); - presentation method (raster, vector); - character width (monospaced fonts); - serif and serif fonts (Times New Roman, Arial). 42
Numbered, bulleted and multilevel lists - used to place various lists in the document Numbered list: 1. First element 2. Second element 3. Third element Bulleted list: First element Second element Third element Multilevel list: 1. First element Second level 2. Second Element 46 Lists
Tables
Creating and modifying a table The sequence of creating a table: When further modifying the table, the following are available: insertion and deletion of rows, columns, cells; changing the width of the columns, the height of the rows (using the mouse or by specifying their exact values in centimeters or percentages); resizing of individual cells, dividing into several or merging with neighboring ones. Table Insert Table 52
Lesson schedule for the week Days of the week Subject Start time Lesson end time Homework Monday Tuesday Wednesday
Hypertext A hypertext document is a document containing links to other documents. A hyperlink is a selected object linked to another file using a hidden address and responding to a mouse click. A hyperlink can point to bookmarks in the same document and to bookmarks in other documents. 56
Practical work 2.4. "Creating and formatting lists" Practical work 2.4, page of the textbook. 58
Practical work 2.5. "Tables" Practical work 2.5, page of the textbook. An example of a table is shown on slide 57 59
Create a table "Schedule of lessons for the week" The table should reflect the following information: - day of the week; - the ordinal number of the lesson; - the name of the subject; - the start time of the lesson; - the end time of the lesson; - homework. Performed in MS Word 60 Practical homework is optional for an additional grade
High speed of translation of multi-page documents (1 page / s) High quality of translation of technical documents, business correspondence and other specialized texts Possibilities of computer translation systems Example: http \\ 63
Optical Document Recognition Systems
Practical work 2.6. "Recognition of" paper "text and translation using a computer dictionary" 72 Assignment: 1.Recognize the encyclopedic article 2.Translate the encyclopedic article from English into Russian 3.form a glossary of terms (table 5 terms from the article) Recommendations for the implementation of the work: Materials 2.6 ... Practical Recognition and Translation
"Texts in computer memory" - Texts in computer memory. "Abracadabra". Text encoding. Code table, international ASCII standard. The word will take 14 bytes = 112 bits of memory, since 1 byte = 8 bits. Example 1: How many bits of computer memory does the word MICROPROCESSOR occupy? Computer alphabet. Principle of sequential coding of the alphabet:
"Coding in Informatics" - About what? where is it stored? how is it coded? Comparison chart. Solving problems for coding information. The essence of coding. Homework: Gen. DNA structure. Properties of the genetic code. Storage of hereditary information. ABOUT WHAT? Hereditary information. Genetic code.
"Determination of the amount of information" - Objectives To study methods of determining the amount of information: quantitative; alphabetical. N = 2I. Not matter and not energy ...? We measure ... An alphabetical approach to quantifying information. The amount of information. Don't be surprised, information can be quantified. Purpose: to find out how information can be measured.
"Sign systems for coding information" - Coding information. What methods and organs of sense does a person use to reproduce information? Electromagnetic waves (radio, television, cell phone). Perception: Visual. Give examples of the use of information and communication technologies. Information coding using sign systems.
"Sign system" - Homework (to prepare for the survey): Give examples of sign systems. Information coding using sign systems. 1. Signs: form and meaning. Information coding. For long-term storage, characters are recorded on storage media. The sign system is based on a set of characters called the alphabet.
"Numbers in the computer" - +. Number forms of signed integers. Representation of numbers in the computer memory. Number 3910 = 100111 2 in two-byte format: 1) A and B are positive: Signed numbers. They have a different view. 3) A - positive, B - negative, | B |<|A|. Арифметические действия. Число 3910 = 100111 2 в однобайтовом формате:
There are 15 presentations in total
Piyaeva Olga Nikolaevna
Place of work: municipal budgetary educational institution "Taraskovskaya secondary school"
Position: IT-teacher
School address: Moscow region Kashirsky district Taraskovo village 22 Komsomolskaya street
Grade: 8
Lesson topic: Encoding of text information. (the first lesson on the topic "Coding information")
Lesson type: learning new knowledge
Lesson type: traditional information technology
Goals:
Educational:
to acquaint students with methods of encoding information in a computer;
consider examples of problem solving;
Developing:
contribute to the development of the cognitive interests of students.
Educational:
to cultivate endurance and patience in work, a sense of camaraderie and mutual understanding.
Tasks:
Educational:
to form students' knowledge on the topic “Coding of text information”;
Developing:
develop the skills of analysis and introspection;
to promote the formation of figurative thinking in schoolchildren;
Educational:
to form the ability to plan their activities.
Equipment:
workplaces of students (personal computer),
teacher's workplace,
multimedia projector,
Software: PC, PowerPoint, tables, diagrams.
Lesson Information Card:
№ p / p
Lesson stage
At-
measure-
new time
Didactic
what purpose
Forms and methods of work
Types of student activities
Organizational
ny moment
2 minutes
Include students in a business rhythm, prepare the class for work
Oral communication from the teacher
The mood for productivity
active
ness
The study
new
material
18 minutes
Form cognitive motives. Ensure learners accept the purpose of the lesson. Form concrete ideas about the coding of text information.
Explanation of the new material using
presentation
Listening and memorizing, answering the teacher's questions, completing the assignment for decoding
information
Physical education
2 minutes.
Prevent fatigue in children
Exercise
Exercise
Consolidation of the acquired knowledge
10 min.
Organize activities to apply new knowledge
Practical work
Practical
work
Initial test of understanding
8 minutes
Reveal the level of primary assimilation of new material
Frontal poll
Differentiated independent work
Answer teacher's questions
Do independent work
Homework
2 minutes.
Give information on homework and instructions on how to complete it
Homework briefing
Writing homework in diaries
Summing up the lesson (reflection)
3 min.
Self-examination by students of understanding the topic
Receiving an unfinished proposal
Discussion of what they learned and how they worked
During the classes.
Organizing time.
Guys, I am glad to see you in full force, in a good mood and I hope for a fruitful lesson.
Sit down.
Now we will conduct a lesson readiness raid with you:
show diaries
show pens
show the tutorials
show notebooks
Everything is ready for the lesson, we can start.
Learning new material
Today we are starting to study the big topic "Coding and Processing of Textual Information", and our first lesson is called "Encoding Textual Information"
On the screen is the first slide of a multimedia presentation with the topic of the lesson.
In today's lesson, we will get acquainted with the methods of coding text that were invented by people at various stages of the development of human thought, with binary coding of information in a computer, we will learn how to determine the numeric codes of characters, enter characters using numeric codes and re-encode Russian-language text in a text editor.
The problem of protecting information has worried people for several centuries.
Codes appeared in ancient times in the form of cryptograms (which in Greek means "secret writing"). Sometimes the sacred Jewish texts were encrypted using the replacement method. Instead of the first letter of the alphabet, the last letter was written, instead of the second - the penultimate, etc. this ancient cipher was called atbash.
Slide show # 2
Before you are several methods of coding text that were invented at various stages in the development of human thought.
- cryptography- it is secret writing, a system of changing the letter in order to make the text incomprehensible to the uninitiated;
- morse code or a non-uniform telegraph code, in which each letter or character is represented by its own combination of short electric current chips (dots) and chips of triple duration (dashes);
- surdogesty- sign language used by people with hearing impairments.
Question: What other examples of encoding textual information can be given?
Students give examples . ( Vigineer cipher, replacement cipher)
Slide show # 3
One of the earliest known encryption methods is named after the Roman emperor Julius Caesar (1st century BC). This method is based on replacing each letter of the encrypted text with another, by shifting in the alphabet from the original letter by a fixed number of characters. So the word byte when shifted three characters to the right, encoded with a word dgmh ... The reverse process of decoding a given word - it is necessary to replace each encrypted letter, with the third one to the left of it.
Slide show number 4
In Ancient Greece (II century BC) a cipher was known, which was created using the square of Polybius. For encryption, a table was used, which was a square with six columns and six rows, which were numbered from 1 to 6. One letter was written in each cell of such a table. As a result, each letter corresponded to a pair of numbers, and encryption was reduced to replacing the letter with a pair of numbers. The first digit indicates the row number, the second the column number. The byte word is encoded in this case as follows: 12 11 25 42
Slide show number 5.
Decipher the following phrase using the Polybius square.
"33 11 35 36 24 32 16 36 11 45 43 51 24 32 41 63"
Question: What did you do?
Student response: We learn from examples
The answer is compared with the correct answer that appears on slide 5.
Binary encoding of text information in a computer
Teacher: Information expressed in natural and formal languages in writing is commonly referred to as text information.
Slide show number 6.
To represent textual information (uppercase, lowercase letters of the Russian and Latin alphabets, numbers, signs and mathematical symbols), 256 different characters are sufficient.
If you add up all the signs:
33 lowercase letters of the Russian alphabet + 33 uppercase letters = 66;
For the Latin alphabet 26 + 26 = 52;
Numbers from 0 to 9
it turns out that you need 127 characters. There are still 129 values that can be used to denote punctuation marks, arithmetic signs, service operations (line feed, space, etc.)
Slide show number 7
According to the formula N = 2 I, you can calculate how much information is needed to encode each character:
N = 2 I 256 = 2 I 2 8 = 2 I I= 8 bits
To process textual information on a computer, it is necessary to represent it in a binary sign system. We have calculated that to encode each character requires 8 bits of information, that is, the length of the character's binary code is eight binary characters. Each character must be associated with a unique binary code from the interval from 00000000 to 11111111 (in decimal code from 0 to 255).
When text information is entered into a computer, it is binary encoded. The user presses a signed key on the keyboard, and a specific sequence of eight electrical impulses (binary sign code) is sent to the computer. In the process of displaying on the computer screen, reverse transcoding is performed, i.e. converting the binary code into its image.
Slide show number 8
The assignment of a specific binary code to a sign is a matter of convention, which is fixed in the code table. An international agreement has been adopted to assign a unique code to each character. ASCII (American Standard Code for Information Interchange) code table has been adopted as an international standard.
This table contains codes from 0 to 127 (letters of the English alphabet, signs of mathematical operations, service symbols, etc.), and codes from 0 to 32 are assigned not to symbols, but to function keys.
Write down the name of this code table and the range of characters to be encoded.
Codes 128 through 255 are allocated for the national standards of each country. This is sufficient for most developed countries.
For Russia, several different code table standards (codes 128 to 255) have been introduced.
Slide show number 9.
Here is some of them. Let's consider and write down their names:
KOI - 8 , Windows, MS-DOS , Mac, ISO.
There are approximately 6,800 different languages in the world. If you read a text printed in Japan on a computer in Russia or the United States, then it will be impossible to understand it. So that the letters of any country could be read on any computer, two bytes (16 bits) were used to encode them.
Let's, with you, also determine the number of characters that can be encoded according to this standard:
N = 2 I = 2 16 = 65536
this number of characters is enough to encode not only the Russian and Latin alphabets, but also the Greek, Arabic, Hebrew and other alphabets.
Physical education
And now let's have a physical education: first, with the tip of your nose, write figuratively on the ceiling "I like computer science."
Physical education for the eyes:
Blink quickly, close your eyes and sit quietly, slowly counting to 5. Repeat 4-5 times.
Extend your right arm forward. Follow with your eyes, without turning your head, for slow movements of the index finger of an outstretched hand to the left and right, up and down. Repeat 4-5 times.
Look at the index finger of your outstretched hand at 1-4, then move your gaze into the distance at 1-6. Repeat 4-5 times.
At an average pace, do 3-4 circular movements with the eyes to the right side, the same amount to the left. Relaxing the eye muscles, look into the distance at a count of 1-6. Repeat 1-2 times.
Consolidation of the acquired knowledge.
No wonder the Roman fabulist Phaedrus said: "Science is the captain, and practice is the soldiers." Therefore, now let's move from theory to practice.
Open the textbook to page 152, find practice # 8, read it.
Write down in a notebook the topic of practical work "Coding of text information", the purpose of the work: to learn how to determine the numeric codes of characters, enter characters using numeric codes and re-encode Russian-language text in a text editor.
Turn on your computers and we'll do the job together.
Task number 1. In the Word text editor, define the numeric codes of several characters:
in Windows encoding;
in Unicode encoding (Unicode)
Launch a text editor Word
enter the command (Insert - Symbol ...). The Symbol dialog box appears. The central part of the dialog box is occupied by the symbol table.
To determine the decimal numeric code of a character in Windows encoding using the drop-down list from: select the Cyrillic encoding type (dec.).
Select a symbol from the symbol table. The character code: appears in the Character Code: text box.
To define a Unicode hexadecimal numeric code using the drop-down list from: select the Unicode encoding type (hex).
Select a symbol from the symbol table. A hexadecimal numeric character code appears in the Character Code: text box.
Using an electronic calculator, convert the hexadecimal numeric code to the decimal number system:
0586 16 = X 10; 1254 16 = X 10; 8569 16 = X 10;
Task number 2. In the text editor Notepad, use numeric codes to enter a sequence of characters in Windows and MS - DOS encodings.
Launch the standard Notepad application with the command (Program - Accessories - Notepad).
Using the additional numeric keypad, while pressing the Alt key, enter the number 0224, release the Alt key, the symbol "a" will appear in the document. Repeat the procedure for numeric codes from 0225 to 0233, a sequence of 10 characters "abcddezhziy" in Windows encoding will appear in the document.
Using the additional numeric keypad, while pressing the Alt key, enter the number 224, release the Alt key, the symbol "p" will appear in the document. Repeat the procedure for numeric codes from 225 to 233, a sequence of 10 characters "rstufhtschshsh" in MS - DOS encoding will appear in the document.
Initial test of understanding
Teacher questions
1. What is the principle of encoding text information used in a computer? (When text information is entered into a computer, its binary coding occurs. The user presses a signed key on the keyboard, and a certain sequence of eight electrical impulses (binary code of the sign) is sent to the computer. converting the binary to its image.)
2. What is the name of the international character encoding table?( ASCII(American Standard Code for Information Interchange - American standard code for exchange information )
3. List the names of encoding tables for Russian-language characters. (KOI - 8, MS - DOS , Mac, ISO , Windows )
The teacher gives out cards with individual assignments. (Petya and Kolya write e-mails to each other in KOI - 8. Once Petya made a mistake and sent a letter in Windows encoding. Kolya received the letter and, as always, read it in KOI - 8. The result was a meaningless text in which the word *** was often repeated ***. What word was in the original text of the letter?
Option 1 - ULBOET (scanner)
Option 2 - RBNSFSH (memory)
Option 3 - RTYOFET (printer)
Option 4 - DYULEFB (diskette)
Option 5 - FTELVPM (trackball)
Option 6 - NPOIFPT (monitor)
Option 7 - RTPGEUUPT (processor)
Option 8 - LMBCHYBFHTB (keyboard)
Option 9 - NBFETYOULBS RMBFB (motherboard)
Option 10 - FBLFPCHBS YUBUFPFB RTPGEUUPTB (processor clock frequency)
Homework
According to N. Ugrinovich's textbook, clause 3.1. pp. 74 - 77
Encode your name and surname in the KOI - 8 code. Write the result as:
binary code
decimal code
Additional task (on the card): decode the text using the KOI -8 encoding:
254 212 207 194 205 213 196 210 207 214 201 218 206 216 208 210 207 214 201 212 216, 218 206 193 212 216 206 193 196 207 194 206 207 206 197 205 193 204 207,
228 215 193 215 193 214 206 217 200 208 215 193 215 201 204 193 218 193 208 207 205 206 201 196 204 209 206 193 222 193 204 193:
244 217 204 213 222 219 197 199 207 204 207 196 193 202, 222 197 205 222 212 207 208 207 208 193 204 207 197 211 212 216,
233 204 213 222 219 197 194 213 196 216 207 196 201 206, 222 197 205 215 205 197 211 212 197 21 203 197 205 208 207 208 193 204 207.
(To live life wisely, you need to know a lot,
Remember two important rules to start with:
You better starve than just eat anything
Informatics and information technology. Textbook for grade 8 / N. D. Ugrinovich. - M. BINOM. Knowledge Laboratory, 2011 .-- 205 p .: ill.
Journal "Informatics and Education", No. 4,2003, No. 6,2006
Informatics 7 - 9 cl. / A.G. Kushnirenko, G.V. Lebedev, Ya.N. Zaidelman, M.: Drofa, 2001 .-- 336 p .: ill.
LESSON DEVELOPMENT "Coding text information"
Grade: Grade 9
Lesson type:
§ familiarization with new material,
§ a practical lesson.
Lesson type: combined.
Lesson Objectives:
§ Didactic: to provide initial comprehension of the new content of the material.
§ Pedagogical: lead students to understand the reasons and ways of transforming and storing text information on a computer in the form of binary code.
Lesson objectives:
Educational:
§ Introduce the concepts of text information, coding of text information, code table.
Developing:
§ To teach how to determine the character code and symbol by code using code tables and a text editor.
§ Teach to encode and recode text information.
Educational:
§ Continue the formation of interest in the subject, the formation of a worldview.
§ To foster a culture of behavior in the classroom, accuracy, independence, the ability to listen.
§ To cultivate personal qualities: activity, the ability to cooperate and work in a group.
§ Prepare students for life in a rapidly changing information world.
Lesson equipment:
§ Textbook by N.D. Ugrinovich Informatics Grade 9, BINOM, Knowledge Laboratory, 2014.
§ Teacher's workplace.
§ Workplaces of students: PC with Windows XP operating system.
§ Text editor Notepad.
§ Multimedia projector.
§ Presentation "Coding of Text Information".
§ Practice cards.
§ Encoding tables.
Forms of education : frontal, individual, group (work in pairs).
Teaching Methods and Techniques: explanatory and illustrative, partly search, verbal (frontal conversation), visual (demonstration of a computer presentation), practical (doing practical work on a PC), reflection (frontal survey).
During the classes
Lesson stage
Activity
Time (min)
Organizational
moment
Checking readiness for the lesson (students have notebooks, textbooks)
Updating
knowledge, repetition of what has been learned
Preparing to study new material, frontal survey
Learning new
material
Lecture accompanied by a multimedia presentation, writing on the board and in notebooks
Practical work
Doing a Practice Activity on a Computer
Anchoring.
Working in pairs
Self-compilation of an assignment for your friend, checking the correctness of the implementation
Lesson summary. Reflection
Teacher message, frontal survey
Homework
Diary entry
After completing a topic, students should
know:
§ the principle of coding text information in a computer;
§ the principle of storing text information;
§ the concept of the encoding table;
§ modern encoding tables;
be able to:
§ determine the character code in the given encoding table;
§ find a character by a given code;
§ select and change different character encodings for text.
Stage 1 of the lesson. Organizing time
Greetings. Checking readiness for the lesson.
Message of the topic of the lesson "(slide 1).
Setting the goals of the lesson (slide 2):
§ Get acquainted with the concepts of text information, coding of text information, code table.
§ Learn to determine the character code and symbol by code using code tables and a text editor.
§ Learn to encode and recode text information.
2nd stage of the lesson. Knowledge update. Repetition of what has been learned
The children are invited to answer the questions (slide 3):
1. What is information?
Answer: this is information about the surrounding world (object, process, phenomenon);
it is a reflection of the surrounding world in the form of signals and signs.
2. What types of presentation information do you know?
Answer: Numeric, text, graphic, sound, video, combined.
3. What is encoding?
Answer: The process of presenting information using a sign system.
Stage 3 of the lesson. Learning new material
Text information is information expressed in natural or formal languages in writing (slide 4).
Text information includes:
§ Russian alphabet letters
§ Latin alphabet letters
§ Numbers
§ Signs
§ Math symbols
Question: What is natural language and what is formal language?
Answer: A natural language is a language that has developed historically and that has arisen naturally. For example, Russian spoken.
A formal language is a language that is artificially invented with strict rules. For example, the language of algebra, the language of the computer.
256 different characters are enough to encode text information! Let's recall the basic formula of computer science and calculate the amount of information required to encode 1 character (slides 5, 6):
N = 2 i, where
N - the number of code combinations
i - the length of the binary code
256 = 2 i 28 = 2 i I = 8 bits
To process textual information in a computer, it is necessary to represent it in a binary sign system. A person distinguishes characters by their outline, and a computer - by their binary codes. When we enter textual information into the PC, its binary coding occurs, i.e. the image of the sign is converted into its binary code. When you press a key, a sequence of 8 electrical impulses is sent to the computer. The character code is stored in RAM (slide 7).
In the process of displaying on the screen, the reverse process occurs (slide 8).
Question: which device is engaged in converting information into binary code and vice versa?
Answer: microprocessor.
The assignment of a specific binary code to a sign is a matter of agreement, which is recorded in the code table (slide 9).
Encoding table- this is a table in which all the symbols of the computer alphabet are assigned serial numbers - codes.
The international standard for PC is the table ASCII - American Standard Code for Information Interchange (American Standard Code for Information Interchange).
The first 33 codes in this table correspond not to characters, but to operations (space, line break, paragraph mark, and others). Codes from 33 to 127 are international (Latin alphabet characters, numbers, arithmetic signs, punctuation marks). Codes from 128 to 255 are national, i.e. in different national encodings the same code corresponds to different characters (slide 10).
There are currently 5 different encodings for encoding Russian letters ( Windows, MS - DOS, Mac, ISO, KOI-8) (slide 11).
Historically, it so happened that the national part of the code tables appeared inconsistently in different countries and in different operating systems. Code tables ISO and KOI-8 appeared in the USSR. Code table MS - DOS was designed for the operating system Microsoft DOS , code table Windows - for the operating system Microsoft Windows ... Code table Mac used in operating systems Mac OS (slide 12).
Texts created in one encoding will not display correctly in another!
Sometimes it becomes necessary to use more than two languages in one text document. For example, when printing text on geometry, you may need Russian characters, Latin letters, Greek letters. How to be in such a situation?
In 1991, a new code standard was proposed, where 2 bytes of memory were allocated for each character. The code table was named Unicode ... In the code table Unicode 65536 characters. This number of code combinations allows you to encode the signs of the languages of almost all alphabets of the world! (slide 13).
4th stage of the lesson. Practical work on the computer
Let's remember the objectives of the lesson. The first goal - to get acquainted with the concept of coding text information, code table - we have achieved.
Learn to encode text information, determine the character code and symbol by code, using code tables and a text editor,practical work will help us (slide 14).
