Class 9|Technical [digitalogy] chapter-1

 

Chap-1                                                                  Number system                                                                                    2076/12/19

v  The way of represent a number in a computer system is called Number system.

v  Types of Number system are:

1.       Binary number system

2.       Decimal number system (dinary)

3.       Octal number system

4.       Hexadecimal number system

A.      The  number system which contain two different digits (0,1)is called Binary number system.

B.      The number system which contain 10 different digits(0,1,2,3,4,5,6,7,8,9) is called Decimal number system(dinary).

C.      The number system which contain 8 different digits (0,1,2,3,4,5,6,7) is called Octal number system.

D.      The number system which contain 16 different digits (0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F) is called Hexadecimal number system.

                                                                                Number conversion

1)Convert (101101)₂ into Decimal number system.

                          Here,

                                (101101)₂=(?)₁₀

                                101101=1*2⁵+0*2⁴+1*2³+1*2²+0*2¹+1*2⁰

                                                =1*32+0*16+1*8+1*4+0*2+1*1

                                                =32+8+4+1

                                                =45

                          (101101)₂=(45)₁₀

 

Note:Other learn in class

 

 

 

Chap-2                                       Binary arthemetic operator

1’s Complement

   Here,1’s complement is 0 into 1 or 0.

                         For eg.010=101

                                               1=0

                                               0=1

2’s Complement

  Here,we have to convert 1’s complement with add with one.

                         For eg.

                         101=010-----------1’s complement

                         010

                           +1

                         -------

                         011---------------------- 2’s  complement

 

Some clue: 100 MSb is 1. First no.is msb

SOME QUESTIONS

1)Subtract 100 from 1000bby using 1’s complement method.

                         1000----------main value

                         0100----------second value

Both has equal bit by adding 0 infront of second value.

                         1011----------1’s complement of second value

                           1000

                         +1011

                         ---------

                    10011------- overflow occur so it omit MSB and add it with remaining digit.

0011

   +1

                        

100

Therefore,100 is answer

 

2)Subtract 1000 from 100 by using 2’s complement method

                         0100----------- main value

                         1000-----------second value

Both has no equal number of digits so,it need to add 0 infront  of main value.

                         0111------1’s complement of second value

                             +1

                         --------

                         1000----------2’s complement of second value

 

                         0100

                         +1000

                          ---------

          1100-------------NO  over flow occur digit occur so,we need to covert into 2’s complement and mark negative sign in ans

0011-----1’s complement of ans

    +1

-----------

100

 Therefore,-100 is ans .

 

 

 

Overflow occur	No over flow occur
1’s complement-omit MSB and add to remaining   2’s complement-omit MSB and remaining is ans.	1’s complement-change into 1’s and –sign   2’s complement-convert into 2’s complement and –sign

SMALL LOGIC GATES — THE BUILDING BLOCKS OF VERSATILE DIGITAL CIRCUITS -  PART 1

By Manish bk

 

                             

 

 

 

 

Chap-3                                                 logic gate concept

1.       Logic gate

The logic gate is an electronic circuit or basic building block of the electronic devices that accept input signal and gives output depend on input.

 

2.       Truth table

Truth table is a table which shows the relation of algebraic expression depend on input signal and output.

 

i)        AND gate(a*b)

ii)       NAND gate(a*b)’

iii)     OR gate(a+b)

iv)     NOT gate(a)’

v)      NOR gate(a+b)’

vi)     X-OR gate a’b+ab’

vii)   X-NOR gate ab+a’b’

v  AND gate

When both the inputs are high,then the output is high.

 

 

A*B

a

 

 

b

 

 

Truth table of AND gate

Inputs		Outputs
A	B	A*B
0	0	0
0	1	0
1	0	0
1	1	1

 

 

 

 

 

 

 

 

 

 

 

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