Define computer? Explain in detail logical organization of digital computer with neat diagram.

Semester :-1

Unit:-1

Define computer? Explain in detail logical organization of digital computer with neat diagram.? 

INTRODUCTION :
                   Computer is a electronic device which stores data, process it, and gives the result consistently, accurately at very high speed according to our instruction. The word computer is derived from the word "compute". It means perform or calculate. So a powerful computer can handle 3 to 4 million instruction per second (MIPS)
Input unit :-
           It is used to send data or programs into computer. There are several kinds of input units are available, they are keywor, light pen, joystick, and mouse, etc.
CPU :-
     Cpu stands for central processing unit. This is the main and most important part of the computer it is made up of three units. They are

• Memory unit
• CU (control unit)
• ALU (Arithmetic and logical unit)

a) memory unit :-
               The function of the memory unit is to store data or programs or information in the format of "ON" and "OFF" states. Because computer is an electronic device which identifies either "ON" and "OFF" states. That's why, all the information or data or programs will be stored inside the computer in the form of "ON" And "OFF" states.
b) CU :-
       CU stand for control unit. This unit to control the overall units either internally (i.e. Memory and ALU) and externally (i.e. Input - output units) connected to computer.
c) ALU :-
               ALU stand for Arithmetic logical unit. It will perform the arithmetic and logical operations.

Block Diagram of Digital computer

Output unit :-
           This unit is used to take the final results. There are two kinds of output units. They are a) Soft copy Device, Ex: monitor and b) Hardcopy Device, Ex: printer, plotter.
      Softcopy device are used to prepare the softcopies (monitor output). Prepare softcopy is used for temporary reference and it will save the stationery and printing cost whereas the hard copy device are used to prepare the hardcopier (paper output). Prepared hardcopy is used for further reference and it will waste the stationary and printing costs for unnecessary output is taken.
Secondary Storage Devices :-
                         This unit is used to store large amounts of data permanently. There are several kinds of secondary storage devices. They are magnetic tapes, magnetic disks, CDs etc.
Peripheral Devices :-
                  Whose devices are connected CPU externally then those devices are called peripheral devices.
Input and output units are called as peripheral devices.