In The Name Of ALLAH,The Most Beneficent and Merciful.

Shahzada Saleem 1421-310026

Muhammad Usman 1421-310060

Data Communications

The way in which data is represented.The sender and receiver use same code.Here we discuss two types of codes….

Jean-Maurice-Emile Baudot  

French telegraphengineer and inventor of the first means of digital communication Baudot code

 Baudot's hardware had three main parts: the keyboard, the distributor, and a paper tape.

Five bits allowed 32 different characters .

Baudot keyboard,telegraph 1884

Values Ltrs Shift

FIGS Shift

Values Ltrs Shift

FIGS Shift

3 A - 23 Q 1

25 B ? 10 R 4

14 C : 5 S

9 D Who are you? 16 T 5

1 E 3 7 U 7

13 F ! 30 V ;

26 G & 19 W 2

20 H # 29 X /

6 I 8 21 Y 6

11 J Bell 17 Z “

15 K ( 0 BLANK BLANK

18 L ) 31 LTRS LTRS

28 M . 27 FIGS FIGS

12 N , 4 SPACE SPACE

24 O 9 8 CR CR

22 P 0 2 LF LF

Symbols are all of equal size and therefore decoding them using a table would be easier Baudot code is resilient in the presence of

transmission errors

Limitation on the number of characters it can represent - total of 62 characters

Apparent lack of logic in the way the characters and the numbers have been allocated - the bit

pattern for the number one (11101) is numerically larger than the bit pattern for the number nine

(00011).  

ASCII stands for American Standard Code for Information Interchange. 

ASCII code is the numerical representation of a character

It is seven bits 128 combinations.

As data is represented by seven bits 128 different combinations are possible

Usually transmitted as 8-bits and thus one bit can be employed for simple error

detection ASCII code is widely used for

representation in the internal structure of a computer and thus translation is not normally

required if information is to be transmitted over a network

Occasionally much of the information to be transmitted will be relatively

similar and thus the seven-bit code can waste space

ThankYou!