Codes: ASCII and UNICODE

Содержание и основные понятия

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Alterna chapter 13
Codes: ASCII and UNICODE
How a computer turns letters into numbers and backwards, from the ASCII to the Unicode table, from even codes to the Fano trees.
The computer only understands numbers.
But we print letters, we read words, we watch emoji.
coding
In this chapter, you will learn how the first ASCII agreement was designed, why it was not enough and how Unicode came into being, bringing together more than 140,000 characters out of hundreds of languages.
GEF
PIF
OGE
EEG
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Relationship to the previous section
B
Chapter 12
We've learned that the amount of information is measured in bits and bytes.
I = N × i
shows how many bits are needed to store the sequence of characters. But how does the computer keep the text exactly? How does one letter "A" turn into a set of bits?
The answer is encoded.
Each encoding defines the correspondence table: "Symbol * number" and "number ~ symbol." The common power of the alphabet (chapter 10), we can calculate the number of bits per symbol. Knowing the code number itself, we can accurately calculate the volume of any text. That's why the encoding is a logical extension of the information theory.
01
Chapter Pages
Five pages with theory, interactors and a bank of assignments.
13.1
ASCII and UNODC
Code history, ASCII table, Unicode UTF-8/16/32, converter, volume calculator
13.2
Equitable and uneven codes
Equal/unequal codes, calculator, decoder
13.3
Trees and Fano condition
Binary trees, BST, bypasses, Fano condition, coding
13.4
EEG/EGL workshop
Filters and Review Tasks
13.5
Polygon examination
Quest 800 XP, test 8 min, open task
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Heading route
Recommended procedure for passing
13.1 ASCII and UNICODE
- See how computers represent symbols, study the ASCII table and converters.
13.2 Equitable and uneven codes
- Axis difference between fixed and variable length codes, work with decoder.
13.3 Trees and Fano Condition
- understand how trees help build efficient codes.
13.4 Workshop
- train on real OGE/EEG review assignments.
13.5 Polygon examination
- Final check with timer and task.
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Links with other chapters
Chapter 10
Alphabet: The strength of the alphabet is the number of symbols that need to be coded.
Chapter 11
Coding: turning symbols into numbers is the basis for working with text.
Chapter 12
Information volume: I = N × i depends on the code selected.