COMPUTER FUNDAMENTAL

Device:-There are three types of devices (Input, Output, Storage device)

Input device:- An input device is an electromechanical device, which accepts data from the outside world, and translates them into a form, which the computer can interpret can interpret. Several input devices are available today-

Keyboard, Mouse, Joystick, Light pen, Track Ball, Scanner, Graphic Tablet, Microphone, Magnetic Ink card reader (MICR) , Optical Character Reader(OCR), Bar Code reader, Optical mark reader(OMR)………………..etc.

Output device: – An output device is an electromechanical device, which accepts data from a computer and translates them into a form, which is suitable for use by the outside world( the users). Several output devices are available today.

Printer, Monitor, Speaker …etc.

Storage device:-A Storage device is a device in which we store the data. Ex- Hard drive, pen drive, DVD, CD………………etc.

 

Memory:-A Memory is just like a human brain. It is used to store data and instructions. Computer memory is the storage space in the computer where data is to be processed and instructions required for processing are stored.

Types of Memory

1. Primary Memory:- Primary memory holds only those data and instructions on which computer is currently working. It has limited capacity and data gets lost when power is switched off. It is also known is main memory. It is divided into two subcategories RAM ( Random access memory) and ROM ( Read-only memory).
2. Secondary Memory:- This type of memory is also known as external memory or non-Volatile. It is slower than main memory. These are used for storing data/ Information permanently. Examples are Disk, CD-ROM, DVD ……………..etc.

RAM:-RAM stands for Random access memory. A RAM constitutes the internal memory of the CPU for storing data, program, and program results. It is a read/write memory. RAM is volatile memory, i.e. data stored in it is lost when we switch off the computer or if there is a power failure. RAM is of two types – SRAM ( Static Random access memory ) and DRAM ( Dynamic Random access memory).

ROM:-ROM stands for Read-only memory. The memory from which we can only read but cannot write on it. This type of memory is non-volatile memory. The information is stored permanently in such memories during manufacture.

Types of ROM

1. MROM ( Masked read-only memory)
2. PROM( Programmable read-only memory)
3. EPROM ( Erasable and programmable read-only memory )
4. EEPROM ( Electrically erasable and programmable read-only memory )

Hardware:-Hardware represents the physical and tangible components of the computer, i.e., the components that can be seen and touched.

Examples of hardware are the following- Input devices ( Keyboard, mouse …….), Output devices ( Printer, monitor …….), Secondary storage devices ( Hard disk, CD, DVD ……..), etc.

Software:-Software is a set of programs, which are designed to perform a well-defined function. A program is a sequence of instructions written to solve a particular problem.

There are two types of software’s  – System software and Application software

System software:- The system software is a collection of programs designed to operate, control and extend the processing capabilities of the computer itself. System software are generally prepared by computer manufacturers.

Application software:-Application software are the software that are designed to satisfy a particular need of a particular need of a particular environment. All software prepared by us in the computer lab can come under the category of application software.

Data:-Data can be defined as a representation of facts, concepts, or instructions in a formalized manner, which should be suitable for communication, interpretation, or processing by a human or electronic machine.

Data is represented with the help of characters like alphabets ( A-Z, a-z ) , digit (0 -9) or special characters( + ,- ,* ,< ,> =   ……etc)

Information:- Information is organized or classified data so that it has some meaningful value to the receiver. Information is the processed data on which decisions and actions are based.

Computer Virus:-A computer virus is created when a programmer puts or infects a disk or computer program with computer code that has the capability to replicate itself, hide, and watch for a certain event to occur, and /or deliver a destructive or prankish payload. Viruses can attach themselves to just about any type of file and are spread as infected files are used by other computers.

COMPUTER- MOTHERBOARD – The motherboard serves as a single platform to connect all of the parts of a computer together. A motherboard connects CPU, memory, hard drives, optical drives, video card, sound cards, and other ports and expansion cards directly or via cables. It can be considered as the backbone of a computer.

Computer Generations

Generations	Period	Based on
First	1946 – 1959	Vacuum tube-based.
Second	1959 – 1965	Transistor-based
Third	1965 – 1971	Integrated circuit-based
Fourth	1971 – 1980	VLSI based
Fifth	1980 – onwards	ULSI based

 

First generation:-The period of first generation was 1946-1959. In this generation computers started with using vacuum tubes as the basic components for memory and circuitry for CPU. These tubes like electric bulbs produced a lot of heat and were prone to frequent fusing of the installations, therefore, were very expensive and could be afforded only by very large organizations.

Some computers of this generation were – ENIAC, EDVAC, UNIVAC, IBM-701, IBM-650 ……………etc.

Second generation:-The period of second generation was 1959- 1965. This generation using the transistor was cheaper, consumed less power, more compact in size, more reliable, and faster than the first generation machines made of vacuum tubes. In this generation, magnetic cores were used as primary memory and magnetic tape and magnetic disks as secondary storage devices.

Some computers of this generation were – IBM1620, IBM 7094, CDC1604, CDC 3600, UNIVAC 1108.

Third generation:-The period of third generation was 1965 -1971. The third generation of computer is marked by the use of integrated circuits( IC’s) in place of transistors, resistors, and capacitors along with the associated circuitry. The IC was invented by Jack kilby.

Some computers of this generation were – IBM-360 Series, Honeywell – 6000 series, PDP ( Personal data processor ), IBM – 370/168, TDC-316………………etc.

Fourth generation:-The period of fourth generation was 1971- 1980. The fourth generation of computer is marked by the use of very-large-scale integrated (VLSI) Circuits. VLSI circuits having about 5000 transistors and other circuit elements and their associated circuits on a single chip made it possible to have microcomputers of fourth generation.

Some computers of this generation were- DEC 10, STAR 1000, PDP 11, CRAY-1 (Super Computer) ……………….etc.

 

 

Fifth generation:-The period of fifth-generation is 1980 – till date. In the fifth generation, the VLSI technology became ULSI ( ultra large scale integration) technology, resulting in chips having ten million electronic components. This generation is based on parallel processing hardware and AI ( artificial intelligence) software.

Some computer types of this generation are – Desktop, Laptop, Notebook, Ultrabook, Chromebook.

Number system:-Every computer stores numbers, letters, and other special characters in coded form. Before going into the details of these codes, it is essential to have a basic understanding of the number system. When we type some letters or words, the computer translates them in numbers as computers can understand only numbers.

Number system	Basic digit	Base	Representation	User
Decimal	0-9	10	(27)10	Human being
Binary	0 ,1	2	(10)2	Machine
Octal	0-7	8	(27)8	Intermediate code
Hexadecimal	0-9 , A-F	16	(27)16	Assembly language

Measurement unit –

1 bit	Binary digit
1 byte	8 bits
1 kilobyte	1024 bytes
1 megabyte	1024 kilobytes
1 gigabyte	1024 megabyte
1 terabyte	1024 gigabytes
1 petabyte	1024 terabyte