Coding/decoding

Содержание и основные понятия

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Alterna chapter 11
Coding/decoding
Code tables (ASCII, Unicode), binary text, image, and sound coding are all GEF/OPFs with interactive OGE/EGE assignments.
In this chapter, you will learn how a computer presents any information in a binary form, get to know the code tables, and learn how to solve the problems of the EEG and the EGE for coding.
GEF
PIF
OGE No. 1-6
EEG No. 4-8
📐
Key formulas
Three formulas to know by heart
Capability of the alphabet
N = 2
i
N is the power of the alphabet, i is the weight of the symbol (bit)
Interpretation of text
I = K × i
K is the number of symbols, i is the weight of the symbol
Images
I = x × y × i
x,y is the size, i is the depth of the color
📊
Interactive graph I = K × i
The text message -- move the slides and see the result.
GEF
OGE No. 1
K
- number of symbols
1
200
1000
i
- weight of symbol (beat)
1
8
32
I =
200
×
8
=
1,600 bits
= 200 bytes (0.2 Kbyte)
Comparison:
SMS: 70×16 = 1,120 bits
Page: 2,000×16 = 32,000 bits
Book: 200,000 x 16 = 3,200 000 bits
11
Chapter Pages
Five pages with theory, interactors and a bank of assignments.
11.1
Coding and decoding
What is coding and decoding? Examples from life. Interactive encryption.
GEF
OGE No. 1-4
11.2
Code tables
ASCII, Unicode, UTF-8/16/32, CP1251, KOI-8. Interactive overview of ASC II.
GEF
OGE No. 1-6
EEG No. 4
11.3
Duplicate coding
Translation of numbers, text code, images and sound.
GEF
OGE No. 1-6
EEG No. 4-8
11.4
EEG/EGL workshop
Coachs of the OGE and the EEG, combined training, scavenger by formulas.
OGE No. 1-6
EEG No. 4-8
11.5
Polygon examination
Final test with a timer (10 questions).
OGE No. 1-7
EEG No. 4-8
📊
What do you study?
🔄
Codeing
What is coding and decoding, examples of life?
📋
Code tables
ASCII, Unicode, UTF-8/16/32, CP1251, KOI-8.
💻
Binary code
Translation of numbers, text coding, graphics, sound.
🎯
Examination preparation
OGE/EGE task bank, timer test.
🖥
Pixel Editor
Draw and look at the binary image code.
🔢
System converter
== sync, corrected by elderman == @elder_man
🚀
Quick Start: Examples
Example 1: Translating a number into a binary system
Objective:
Move the number 42 to the binary system.
Решение:
42 / 2 = 21 (ост. 0)
21 / 2 = 10 (ост. 1)
10 / 2 = 5 (ост. 0)
5 / 2 = 2 (ост. 1)
2 / 2 = 1 (ост. 0)
1 / 2 = 0 (ост. 1)
Читаем снизу вверх:
101010₂
Example 2: Full text in CP1251
Objective:
Text of 500 characters in CP1251.
Решение:
CP1251: 1 символ = 1 байт
500 × 1 =
500 байт