Computer Logic

Computer Logic

If on = 1                                              Binary System

If off= 0

Transistors are Switches

2 state device can be only of 1 or 2 possible states (1 or 0)

How many different values can be represented with 3 bit? 8 different combinations

How many different values can be represented with 4 bit? 16 different combinations.

You need to know the weights- 1,2,4,8,16,32,64,128,256,512,1024,2048

Number Conversions-

·         Hexadecimal- Base 16

·         Decimal-Base 10

·         Binary Base 2

Least Significant Figure –LSB

Most significant Figure -MSB

Hexadecimal – 0-9 ,10-15 A-F                                                                                      Interchange

A        S       C     I     I

American                                                                    Standard                            Code For               Information

·         Ascii is an 8 bit code used to represent characters in binary

We say that :

·         A bit is known as- 1-0

·         Byte -8 bits

·         1 kilobyte -1024 bytes

·         1 Megabyte -1024 kilobytes

·         1 giga byte – 1024 mega bytes

·         1terrabyte- 1gigabyte

Analogue devices-

traditional clock/speedometerData changes continously

Digital devices-a device that shows data at descrete intervals

Modem -Converts between the analogue signals. used in telephone cables to digital signals