Personal computer

Definition Of ComputerThe computer is derived from wordCompute. The word ‘compute’ means to calculate so ‘Computer means the devices, which performs calculations. It is an electronic device that is used to calculate and store any kind of data .It takes data ,stores the data, processes the data and gives the desired output inthe desired format.Hence computer acts as a device that transforms data into information. Data can be like name, age, height, weight etc of a person.

May 3, 2023Amamdeep Singh

Computer Calculator1. Computer works faster than calculator.

1. Calculator is slow.

2. Computer has more memory.

2. It has very less memory.

3. It provide facility to use alphabets as well as numbers.

3. In calculator we cannot use alphabets.

4. It provide facility to take output inPrinted form.

4. Calculator only provides output on the screen.

Difference between computer and calculator


Speed:- Computer can work at very high speed. Computer can process large amounts of data in a short time where as humans take long time.

Accuracy:- The computer performs all the calculations accurately, but an error can occur only due to the inaccurate data. If the user enters a wronginput then the output will also be wrong.

Storage:- A computer can store large amount of data. The computer not only store the data but can also give back the data within seconds that the user wants.

Characteristics


Diligence:- A computer can work for long time because a computer is free from tiredness and lack of concentration and even does not get bored whereas the human beings get tired very soon and even lose concentration and hence make errors.

Versatility:- Computer can perform any type of task.Computers and can send and receive data. They can perform simple as well as complex task.

Intelligence:- Computers do not have any intelligence of their own. It can perform only those tasks that are instructed by human beings. Therefore it needs to be told what it has to do.

Features of Computer


Computers are used in schools, colleges and universities for education purposes.

Computers are also used for playing games, watching movies, listening to music etc.

They are also used for defense and sports purposes.

They are used in weather forecasting and in flight simulation (training to pilots).

Applications/Uses of Computer


Computer are used for railway and air ticket booking.

Computers are used in banks for maintaining records.

Audio or video composition and editing havebeen made much easier by computers.

Computers are used to access internal facilities.

Computers are used to make movies and mixing songs.

Computers are used for Desktop publishing.

Uses of Computer


Computer follows only those instructions which are entered by the user.

If there is a power failure we can’t work on the computer.

A computer cannot think itself.

Disadvantages of Computer


Hardware:- All the physical parts of the computer constitute hardware . It acts as a tangible component that we can see and touch. It includes the input & output device which process data & perform many tasks.

Software:- Any written thing is known as ccomputer software. Software is a collection of programs, rules, procedures & related data. It provides intelligence to the computer. It acts as an intangible component that we can’t touch. Simply any thing in written from is known as software.

Basic Construction of Computer


Computer System= Hardware + Software Hardware= Internal Devices + Peripheral

Devices

Basic Constructions of Computer

ProcessingInput Output

Storage


Input:- The data from outside through various input devices like keyboard, mouse etc. is given to the computer system.

Processing:- The CPU processes the input data and converts it into output.

Output:- Output is what the computer gives you, this could be information on a screen, loudspeaker sound or printed page.

Storage:- The output obtained after processing is then stored in the storage devices. The stored information can be accessed again & again anytime.

The Basic operations of computer


The first generation computers used vacuum tubes and punched cards to input data.

These computers used magnetic tapes for storage.

These computers could perform calculations in milliseconds but were large in size and consumed more power and generated too much heat and burnt frequently. They required continuous maintenance.

The programming was done in Machine and Assembly Language.

First Generation Computer (1940-1956)


In second-generation computers transistors were replaced with vacuum tubes.

The size of transistors was much smaller as compared to the vacuum tubes.

These computers consumed less power and produced very less heat.

They were 10 times faster than the first generation computers.

These were less costly as compared to vacuum tubes.

The programming was done in high-level languages, like FORTRAN. COBOL, ALGOL and SNOBOL.

Second Generation Computers (1956-1963)


Minicomputers were introduced. Time-sharing operating systems came into

being. Secondary storage capacity also increased

with improved magnetic disks and tapes. The speed and reliability was increased as

compared to second-generation computers. Third generation computers could perform million (106) of instructions per second.

The programming languages used by these computers were COBOL, PASCAL and BASIC.

Third Generation Computers (1963-1975)


These computers used circuits with very large scale integration (VLSI).

These computers have very high processing power. They have reduced size. They have high reliability, low maintenance and

less power consumption. New operating systems like MSDOS, Windows,

AppleOS were introduced.

Word processing packages and spreadsheet pack ages were developed.

Programming language used in these computers was C.

Fourth Generation Computers (1975-1989)

Microcomputers:- Microcomputers are smaller in size, are less expensive and have less memory. These computers allow only few peripherals to be attached. These come under the following categories:-

Personal computers:- Personal computers are desktop designed for an individual’s use. These help the persons to complete their work more productively. The most common applications of PC are word processing, preparing spreadsheets and managing database etc.

Mainframe Computers:- Mainframes are huge, multi-user systems designed to handle processing jobs in large organizations where the records of thousands of employees have to be processed.

Classification of Computers


These computers used circuits consisting of ULSI (Ultra large Scale Integration).

They used the optic fiber technology. It is based upon the Artificial Intelligence,

Robotics and expert systems. These computers have high processing speed

and are very reliable. PCs became very popular. Optical disks called CD-ROMs came into

existence. Internet came into being because of

networking.

Fifth Generation Computers (1989-Present)


These are multi-user systems that can handle the calculation needs of a small organization. They have large storage capacity and high speed. People use them by means of personal computers. They support fast operating peripherals like high-speed printers that can print hundreds of lines per second.

Supercomputers:- Supercomputers are ultra fast computers designed to process huge amounts of scientific data. These are used to design & control automobiles, missiles, space shuttles etc.

Minicomputers and Supercomputers


Computer Basic diagram

ALU

CU

Input Unit Output Unit

Memory Unit


Input Unit:- Data and program is entered into the computer system before any operation has to be performed on it. Programs are the set of instructions. The data is the raw information on which these instructions will operate. The process of transferring the data from the outside environment to the computer system is done using the input devices such as keyboard, mouse, card reader etc.

Output Unit :- The output unit receives the data from the CPU in the form of binary digits and converts it into human readable form through output devices such as monitors, printers etc.

Components of digital computer


Cache Memory

Main Memory

Cache Memory

CPU


It is considered to be the brain of the computer. It is a chip that contains all the circuits for performing arithmetic & logic operations& directing the data to and from the memory. To do this data must be sent out of CPU to the output device like printers, monitors, etc.

Central Processing Unit (CPU)

Control

Register set

ALU


1. Programmable Read Only Memory (PROM):- A PROM is used to record information in the PROM chip. Information once programmed into the PROM chip is permanent in the PROM chip is permanent and cannot be changed or erased. The process of entering the information into the PROM chip is Known as “burning the PROM”.

2. Erasable Programmable Read Only Memory:- An EPROM is an erasable PROM. Exposing it to high intensity ultraviolet light for 30 minutes can erase the contents of an EPROM chip. The EPROM chip is cheap reliable and widely available.

Types of ROM


MemoryMemory Hierarchies

RAM ROM

SRAM DROM PROM EPROM

EEPROM UVEPROM


Keyboard:- This device resembles a typewriter and is today’s most widely used device to input information in the form of words and numbers. Like typewriter keyboard contains alphabetic, numeric and special characters. The special characters. The special keys include control, Shift and alt, Return, Escape, Arrow keys and Function keys.

Mouse:- is a pointing input device, which is used to point of selecting items from menus and is used for drawing purpose. When the user rolls the mouse across a flat surface, such as desk, the screen cursor moves in the direction of the mouse’s movement.

Input Devices


Track ball:- It is a pointing device that consists of a ball on top and can be rotated with hand in any direction. The whole device does not move, it remains at its same position.

Light Pen:- It is a pen shaped device made up of light sensitive cell which are placed in the small tube. It contains the light receptor and when the tip of the pen is moved over the screen surface.

Other Input devices


Introduction:- Output means to receive results. Device means machine. The output devices are those devices which allow the user to receive the processed data (results) from the computer. There are two types of outputs produced by output devices:-

Soft Copy:- An output that is displayed on the screen stored on magnetic media such as magnetic disks and tapes is Known as soft copy output. It is temporary in nature.

Hard disk:- An output that is produced on a paper through a printer or a plotter is known as hard copy output. They are permanent in nature.

Output Devices


First Generation Computer Picture


Second Generation Computer Picture


Third Generation Computer Picture


Fourth Generation Computer Picture


Fifth Generation Computer Picture


Impact Printer:- Impact printers are those printers are those printers where a hammer strikes the paper through liked ribbon. Because of the hammering action impact printers are noisy in nature. Examples:- Dot Matrix Printers, Daisy Wheel Printers.

Character Printers: - These printers print one character at a time. These are 2 types:

Daisy Wheel: These printers are rarely used any more. A daisy wheel printer strikes hammers character stamps (like those on typewriters) against a ribbon to produce high quality text output. The character patterns are all arranged around edge of a wheel.

Impact Printers


Daisy Wheel Printer Picture


These Printers print the characters by putting dots on the paper. These do not give better print quality but are faster in speed about 30 to 600 characters per second. These can also be used to print graphics. In this printer the hammers are striked on the ribbon to produce the desired characters.

Dot Matrix Printer


Dot matrix and daisy wheel printers both printers both print only one character at a time. For that reason they are called character Printers. In contrast a line print prints a whole line (typically 80 or 132 characters) of text . These printers are very fast.

Drum Printers: These printers print the line by rotating drum having a ring of characters for each print position. The hammer strikes each character of the drum simultaneously so the entire line is printed for he full rotation of the drum.

Line Printer


Drum Printer Photo


These printers use technology where there is no direct contact between the print head and paper giving longer life to the print head. They print characters by spraying small drops of ink on to paper. Because there is no hammering action non impact printers are quite but cannot paper. Examples include inkjet, laser printer etc.

Laser Printer: Laser Printers are called page printers because they print a whole page at time. A laser beam is used to draw the image to be printed onto a light sensitive Drum.

Non-Impact Printer


They print spray the ink from the tiny nozzles through an electric field that arranges charged particles ink into characters. It prints 500 characters per second. These are cheaper than the laser printers but do not give better print quality as compared to laser printers.

Inkjet Printer


This printer use heat sensitive paper on which hot needles are pressed to form characters. They give better print quality but maintenance is costlier.

Thermal Printer


Plotters use pen or inkjet approaches. Plotters are used for high quality pictures and drawings. These are used for printing high- resolution images like charts, maps, engineering and scientific applications. Plotters are normally very slow in motion because of the excessive mechanical movement required during plotting.

Plotters


Display Devices:- The display devices are those devices which are used to graphically display the image of an object on the screen. The graphical display is in the form of pixels. Pixels is the smallest element on the pixels, the quality of display will be better.

CRT (Cathode Ray Tube):- It resembles television. The CRT basically consists of the various components like electron gun, focusing system, deflection system, cathode, filament and the phosphor coated screen. In CRT the beam of electrons is emitted from the electron gun and passes through the focusing system.

Soft Copy Devices


It is a thin lightweight display device used for displaying information such as text, images and moving pictures. These are less bulky in size. These are used in the digital watches , calculators and portable computer.

Monitors:- It is also known as video display units (VDU). This is the most widely used medium to view the output. It comes in various sizes and is available in various modes for text and graphical outputs. An image displayed on the screen is made up of dots called pixels. If you look closely at the screen you may be able to a see these pixels.

LCD (Liquid Crystal Displays)


Floppy Hard Disk

Floppy is used to store less data.

Used to store more data.

Speed to access data is slow.

Speed is faster than floppy.

It has less cost. It has more cost than floppy.

Life is less. Life is more than floppy.

It is made of plastic. It is made of silicon.

Floppy and Hard Disk


Permanent storage:- Here the data stored in these devices is retained even when the power is off that is why it is why it is known as non-volatile memory.

Mass Storage:- Large amount of data is stored in these devices. These devices are helpful everywhere where large amount of data is used to be stored.

Cost Effective:- The secondary storage devices are much more cheater than the primary storage. Portable:- The secondary storage devices can be used to transfer the data from one computer to another.

Characteristics of Secondary Storage Devices


Hard Disk:- It is made of rigid metallic platters works same as floppy disks.

These are generally permanently covered in the disk drive.

These are capable of storing large amounts of data in range from 40 GB (Gigabytes) to 1 TB (Terabytes)

These disks drives can have four or more disk platters in sealed unit .

In most of these disk units the read/write head never touches the surfaces of the disks giving more life to the disk as compared to floppy disk where there is a mechanical touch between the disk and the read/write head.

Types of Disks


It is a common form of removable storage, floppy disk are extremely inexpensive and easy to save information. It is divided into tracks and sectors. It is also a type of secondary memory but its capacity of storing data is less as compared to hard disk. It is used to store the data which we need to transfer from one location to the other or to save copy of the data, otherwise the speed to access it is slow, its life period is also short as compared to hard disk.

Floppy Disk


Introduction:- A ‘Language’ acts as a communication tool between two persons. It is medium of communication which is used for understanding & expressing each other’s ideas, But a computer system does not understand the natural language, so for this, specific programming language is developed.

Computer Programming System:- A special language used to provide instructions to a computer system is known as computer programming language. It is a set of symbols, rules, grammar and characters that are used to write instructions to communicate with the computer.

Computer Language


Simplicity:- A good programming language language must be simple and easy to learn and use. It should provide simple concepts, which can be easily compared.

Naturalness:- A good programming language should be natural for the application, for the application, for which it has been designed. That is, it should provide proper operators, data structures and a natural syntax to help the users to solve their problem easily and efficiently.

Characteristics of Good Programming


There are many computer languages available and categorized:-

Machine Language Assembly Language High Level Language Introduction of Machine Language:-

Machine Language is a low-level language that a CPU understands. The machine language of a computer is written in the form of 1 and 0. it is also known as binary language.

Classification of Programming Language


It is very difficult to remember the codes in the form of 0’s and 1’s so a language is developed in which mnemonics (symbol and alphabets) are used is known as assembly language. Here the word ‘mnemonics is pronounced as ‘nemonics’ where letter ‘m’ is silent.

High Level Language:- The high level language is justbased on the natural english language that is very easy to understand. The instructions are written using English words. The instruction written in english language are not understand by the computer that is why these are converted into machine language with help of translator.

Assembly Language


The End SlidesFor Amandeep Singh

Personal computer

Education

Transcript of Personal computer