Introduction To Computer

 Introduction to computer 

Introduction 

The term computer come from the word compute which means calculation a computer is an electronic machine that accept data from the user processes the idea by performing calculation in operating on heat and generates the desired output result computer perform both simple and complex operation which speed and accuracy 

01.What do you mean by computer ?

Meaning 

computer is electronic machine that come that can store find and arrange information calculate amounts and control other 

02. Definition of computer?

Definition

According to Charles Babbage "computer is a machine would be able to handle the basic calculation thus eliminating human error"

03.what are the fundamentals of computer ?

Fundamentals of computer

1. Data

Data is a collection of RAW fact or unprocessor item which can include text number audio and image or symbol for example Hassan 18 5

Name of the student and other marks in different subject listed in random order

2. Information

It is the data that is poses and presented in an organised manner 

for example 

Hassan=place

Age=18

Room no.=5

When the names of student are arranged in alphabetical order total and average marks are average marks are calculated and presented in a tabular form it is information

3. Program

Set of instruction that enables a computer to perform a given task

04.what are the characters of computer?

Characteristics of computer

The come characteristics of computer that have words made them so powerful and universally powerful or speed accuracy Delhi games versatility and storage capacity latest discuss them

1. Speed

The computer was invented as a high speed calculator this has lead to many scientific project which were previously impossible electronic pulses travel at incredible speed and because the computer is electronic it is internal speed is virtually instantaneous

2. Stage

In the computer the internal memory of the CPU is only large enough to written a certain amount of information it is there for impossible to store in inside the computer the records for example of every premium bond and the name and address of their owner all of the this data is stored outside of the memory of CPU on axillary are secondary storage devices small section of the total data can be access to very quickly by the CPU and brought in the main internal memory as and when required for processing 

3. Accuracy

The computer is considered as a high error in machinery can akkar but due to increase efficiency in error detecting technology this random leads to false result almost without exception the error detect in computer are due to human rather than the technical weakness such that to imprecise thinking by the programmer or to in accurate data are the poorly design system

4. Versatility 

Computer sim capable of performing task get the computer itself as only limited ability and in the final analysis actually perform only four operation

A. It exchanges information with the outside world via I/O device

B. It transfers data internally within the CPU

C. It perform the basic arithmetical operation

D. It perform operation of comparison

5.Automation

A computer is much more than an adding machine calculator or check out till all of which require human operation to press the necessary key for operation to be performance once a program is in the computer's memory the individual instruction are then transfer one after the other to control unit for execution

6.Diligence

Being a machine a computer does not suffer from the human traits ab tiredness and lack of concentration if 3 million calculation have to be perform it will perform three million calculation with exactly the same accuracy and speed as the first this factor may causes those whose job or highly repetitive to regret the computer as a threats

05. Explain the block diagram of computer ?

Block diagram of computer

It is a pathway which shows the flow of data from one component to another a computer can process data pictures sound and graphic they can solve highly complicated problems quickly and accurately.

Block diagram of computer 

1. Input unit:

Computer need to receive data and instruction in order to solve any problem therefore we need to input the data and instruction into the computer the input unit consist of one or more input devices keyboard is the one of the most commonly used input devices other commonly used input devices are listed below:

a.mouse

b.magnetic tape

c.keyboard

d.scanner

e.joystick

a. Mouse:

Mose is the most popular pointing devices. It is very famous karjar control devices having a small palm size Box with a round ball at his base which census the movement of the most and sends corresponding signal to sipu when the mouse button are pressed.

b. Floppy disk drive:

A floppy disk drive is a hardware devices that drives data storage information floppy disc drive are used for reading and writing on removable floppy disc.

c. Magnetic tape:

Magnetic tape is a type of physical storage media for different kinds of data it is considered and analogue solution in contrast to more recent type of storage media such as solid state disk device.

d. Keyboard:

Keyboard is the most common and very popular input device which help to input data to the computer the layout of keyboard is like that of traditional typewriter all though there are some additional key provided for performing additional function

Type of keys 

*Typing keys

*Numerical keys

*Functional keys

*Control keys

*Special purpose keys

e. Scanner:

Scanner is an input device which capture image from the source which are then converted into a digital form that can be stored on the disk this images can be edited before they are prepared.

f. Joystick:

The function of the joystick is similar to that of a mouse it mainly used in computer added designing (CAD) AND PLAYING COMPUTER GAMES.

2. Storage Unit:

Storage unit of the computer holds data and instruction the tar enter through input unit before they are process it preserve the intermediate and final results before these are sent to the output devices it also shares the data from the letter used the various storage devices a computer system are divided into two categories.

a. Primary Storage :

Stores and provides very fast this memory is generally used to hold the programs being currently executed in the computer the data being received from the input unit the intermediate and final result of program

The primary memory is the temporary in nature the data is lost when the computer is switched off.

example for primary memory

(i)Random access memory

(ii)Read only memory

(iii)Flash memory

(iv)Cache memory

(i) Random access memory :

Random-access memory  is a form of computer memory that can be read and changed in any order, typically used to store working data and machine code.[1][2] A random-access memory device allows data items to be read or written in almost the same amount of time irrespective of the physical location of data inside the memory, in contrast with other direct-access data storage media (such as hard disks, CD-RWs, DVD-RWs and the older magnetic tapes and drum memory), where the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement.

(ii) Read only memory :

Read-only memory (ROM) is a type of non-volatile memory used in computers and other electronic devices. Data stored in ROM cannot be electronically modified after the manufacture of the memory device. Read-only memory is useful for storing software that is rarely changed during the life of the system, also known as firmware. Software applications (like video games) for programmable devices can be distributed as plug-in cartridges containing ROM.

(iii) Flash Memory:

Flash memory is an non electronic devices that can be electrically erased and reprogrammed. The two main types of flash memory, NOR flashand NAND flash, are named for the NOR and NAND logic gates. Both use the same cell design, consisting of floating gate MOSFETs. They differ at the circuit level depending on whether the state of the bit line or word lines is pulled high or low: in NAND flash, the relationship between the bit line and the word lines resembles a NAND gate; in NOR flash, it resembles a NOR gate.

(iv) Cache Memory :

cache memory, also called cache, supplementary memory system that temporarily stores frequently used instructions and data for quicker processing by the central processing unit (CPU) of a computer. The cache augments, and is an extension of, a computer's main memory.

b. Secondary memory:

Secondary memory is a permanent memory it is used like archive it's Thor several programs documents database etc the programs that you run on computer are first transfer to primary memory before it is actually run when ever the result are saved again they get stored in secondary memory.

Secondary memory is lower and cheaper than primary

Examples for secondary memory

Hard disc

Compact disc

Pen drive

Removable disc

3. Memory size:

A digital computer use the binary system such as OS

Each character are a number is represented by an 8 bitcode

The set of 8 bit is called a byte

A character occupies 1 byte space

A numeric occupies 2 byte space.

Byte is the space occupied in the memory the size of primary storage is specified in KB kilobyte or MB megabyte 1 KB=1024 byte 1MB=1000KB

The size of the primary storage is a typical PC usually starts at 16 MB PC having 32 MB 48 MB 128 MB 256 MB memory quit common.

4. Output Unit :

The output unit of a computer provides the information and results of a computation to outside world printer visual display unit are the commonly used output devices other commonly used output devices are floppy disc and magnetic tape drive 

Examples are sum of the output units are

a. Monitor

b. Printer 

c. Speaker

d. Projector

e. Headphone

a. Monitor:

Monitor commonly called as visual display unit VDU are the main output device of a computer it form images from tiny dots called pixels that are arrange in a rectangular form the sharpness of a image depends upon the number of pixels

Two kinds of viewing screen monitor

*Cathode Ray tube (CRT)

*Flat pannel Display

b. Printer:

A printer is output device that produces a copy of pictorial are textual files generally over a page its primary function is to print the information on page.

There are two types of printer

*Impact printer

*Non impact printer

c. Speakers :

Speaker is an output device that converts electrical instructions into a sound signal. It helps you to listen this sound signal as an output of what you enter data into a computer.

d. Projector :

A projector is output and optical device that presents visual content like moving or stationary image on the screen. This projecting devices are generally applied in auditorium and cinema theatre.

f. Headphone :

Headphones operate on the same principle of as a speaker operates. This only difference between headphone and speaker is the frequency of the Sun with the help of speaker the release song can cover a large area while with the help of headphones.

06.what is software and explain its types?

SOFTWARE AND ITS TYPE  

Software :

In a computer system the software is basic Ali as set of instruction or commands that tells a computer what to do or in other word software is a computer program that provides a set of instruction to executa uses comment and tell the computer what to do.

1. System Software :

System software is a software that directly operate the computer hardware and provide the basic functionality to the user as well as to the other software to operates smoothly 

Types of system software

(i) operating system (OS):

It is the main program of computer system when the computer system on it is the first software that load into the computer memory basically managers all the resources such as memory CPU printer hard disc etc and provide and interface to the user which helps the user to internet with the computer system 

for example: Linus,Apple,Mac OS, Microsoft Windows.

(ii) Language processor:

As you know that system software convert the human readable language into a machine language and vice versa so the conversion is done by the language processor it converts program written in high language programming language like javas c++ python etc into set of instruction

(iii) Device Driver:

A device driver is a program or software that control a device and helps the device to perform its function every device like a printer mouse modem extra needs a driver to connect with the computer system ethically.

2. Application software:

Software that performs special functions that are much more than the basic operation of the computer is known as application software

Types of application software

(i) General Purpose Software:

This type of application software is used for a variety of task and it is not limited to performing a specific task only.

For example MS word ,MS Excel etc

(ii) customised software :

This type of application software is used for design to perform species are functions are design for specific organisation

(iii) utility software :

This type of application software is used to support the computer infrastructure it is designed to analyse configure optimise and maintain the system.