computer

1
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Chapter-2 Encoding Schemes and
number systems

Introduction
The mechanism of converting data into an equivalent cipher using
specific code is called encoding.
When a key on the keyboard is pressed, it is internally mapped to a
unique code, which is further converted to binary.




Example 2.1 When the key ‘A’ is pressed (Figure 2.1), it is internally
mapped to a decimal value 65 (code value), which is then converted
to its equivalent binary value for the computer to understand.
2.1.1 American Standard Code for Information Interchange
(ASCII)
Encoding scheme ASCII was developed for standardising the
character representation. ASCII is still the most commonly used
coding scheme.
• ASCII value of D is 68 and its equivalent 7-bit binary code =
1000100
• ASCII value of A is 65 and its equivalent 7-bit binary code =
1000001



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, 2
These notes are provided by studifysuccess.

• ASCII value of T is 84 and its equivalent 7-bit binary code =
1010100
• ASCII value of A is 65 and its equivalent 7-bit binary code =
1000001




www.studifysuccess.com Made by Vrinda Rastogi