*Functions of computer;-
It is divided in to three types,such as-
1.In put data/In put device
2. Out put data/Out put device
3.Processing data
1.Input data/Input device;-
Through which we can enter some information data in the system is known as input data/device.
Ex;-key board, mouse and scanner.
( I ). key board;-
It is an input device. key board are divided in to two types, such as-
i.General key board (minimum 104 key)
ii.Multi media key board ( minimum 122 key )
( II ). Mouse;-
Mouse is also an important input device. There are three bottoms available in a mouse. The left bottom use for general purpose,the right most bottom is use for special purpose and middle bottom is use for scrolling purpose.Mouse is divided into four types,such as-
i. optical mouse
ii. serial mouse
iii. bus mouse
iv. mechanical mouse
(III). Scanner;-
It is an input device.It is also knows as photo copy machine.It create a copy of an image and transfer to the disk.Scanner is divided into three types , such as –
(i). MICR-It stand for magnetic ink character reader. It is an input device.It is used for read the cheques in the bank.
(ii).OCR;-It stands for optical character reader.It is used for check the exam paper . Where we can create the mark through pen or pencil on the special designed paper.
(iii) BCR;-It stands for bar code reader.It used to read the bar code through which we can know about the serial number,company name , manufacturing date and price etc.
2.Output data/device;-
Through which we can display our processing information or data is known as output device.
Ex;-monitor , printer , speaker.
(I)Monitor;-
Through 15 is device, we can display our processing information in 15 visual format.
*Types of monitor;-
1.CRT;- calsode ray tube
2. LCD;- liquid crystal display
3.LED;-light emitting diodes
4.PDP;-plasma display panel
5.VFD;-vaculme floristant display
6.ELD;-electric luminescent display
(II).Printer;-
It is divided into two types, such as-
(i).Impact printer
(ii).Non impact printer
(i).Impact printer;-Impact printers are these types of printer key-heads are direct connect with psychical paper.
Ex;- dmp and daisy wheel.
i.DMP;-It stands for dot merit printer in this types of printer,we can printout our information with doted format.
ii.Daisy wheel;-In this types of printer the key heads at around a hub at the time of printing .
3.Processing device;-
Through which device,we can processing the information or data is known as processing device.
Ex;- CPU
*CPU;-It stand for central processing unit.It ies other wise known as brainier computer .It is divided in to three types ,such as-
I.control unit
II. ALU
III.memory unit
(I).Control unit;-It control ALU and memory unit.
(II).ALU;-It stands for arithmetical and logical unit . It mentain all types of arithmetical and memory work in a system.
(III).Memory unit;-The storing capacity of a device is known as memory unit .It is divided into two types,such as-
1. primary memory
2. secondary memory
1.Primary memory;- which memory direct attached with CPU is known as primary or be for the actual processing the data is to be store a small is storage area. The small in storage area is known as primary memory. I is divided into two types, such as-
a.RAM
b. ROM
a. RAM;- It stand for random access memory.It is divided into four types ,such as-
(i) S_RAM- It stand for static random access memory. It can not modify its information because it always in starting position.
(ii).D-RAM- It stands for dynamic random access memory.It is not stable it always varies from time to time .
(iii).F_RAM-It stand for furrow magnetic random access memory.It helps to starting storage of data u product against powerful.
(iv) V- RAM -It stand for video random memory .It contains all the graphical information.
b. ROM;-It stands for read only memory.It is divided into four types,such as-
(i)E-ROM-It stands for erasable read only memory.In this types of ROM can cease the programs of a file.
(ii)P-ROM-It stands for programmable read only memory. In this types of ROM the information are store in la-tile mode.
(iii).EP-ROM-It stands for erasable programmable read only memory.This types of ROM can be program erase 15 rough ultraviolet light.
(iv).EEP-ROM-It stands for electronically erasable programmable read only memory.It can erase a program in electronic process.
2.Secondary memory;-It is a place where information’s are store for 15 feature purpose and recall.When it necessary .It is of two types ,such as-
(i).Disk
(ii)Tape
It is a physical device. It is of 15 re- types such as-
1.Floppy disk
2.CD/DVD
3 HARD DISK
4.. pen-drive
Usefull