BASICS. Computer word is defined from Latin word “compute”, computer means to calculate calculate..
WHAT IA COMPUTER? :Computer is an electronic device, device, which take data in input and gives result is output.
(Or) Computer is an electronic device, device, which capable of performing arithmetic and logical operations at high speed and it can store unlimited data. Data means meaningful information.
Computer stands:Computer stands for Commonly Oriented Machine Particularly Used for Trade Education R esearch esearch It is stands for “commonly for “commonly oriented machine particularly used for trade education research.”
Father of computer:An English mathematician invented a difference engine around 1822. This performed algebraic expressions and mathematical tables up to 20 decimal places. Charles Babbage invented the first electronic machine named by analytical engine in 1832. 1832. The of analytical engine and procedure of data processing technology is used in this Generation also. also. So that he is called by the name of father of computers .
Charles Babbage.
Fist computer ENIAC{E ENIAC{Electronic Numerical Integrated And Calculator.} :28 January 2011
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BASICS. Invented in 1946 and it performed only additions. This is also calles as adding machine.
Fist programmer :Lady august ada love lace is charls Babbage assistant programmer.
History of computer:ABACUS:Abacus was the earliest known machine used for computation. It is in the form of wooden frame containing m etallic wire on which pebbles or beads could side. ABACUS was invented way back 2000-3000BC and it’s used up to 16th century. century.
BLAISE PASCAL:In 1642 the French mathematician Blaise Pascal desired a calculating machine. With this machine addition and subtraction could be performed. This machine was later modified by German mathematician Gorrfried Leibnitz in 1671and 1671and introduced the facility of multiplication of multiplication and division to Pascal’s machine. machine. This was the first machine to multiply and divide directly.
Advantages of computer:
Doing repetitive tasks.
Saving time & human power.
Getting Accurate Result.
The requirement of machine to make the toughest calculation faster and with lesser application of brain was the motivation force behind the invention of computer.
We can print stored data.
We can view the store information in any time.
Work firstly compare to human being.
W.W.W{ {World Wide Web}) Internet(sending mails through W.W.W
We can do calculation & equation.
We can do picture animation.
We can do computerized accounting
.
Disadvantages of computer:
Computer can’t think itself.
Literate or illiterate operates computer.
The user is not sitting properly in front of the computer, he will attack by the backbone ache.
The eyestrain attacks to the regular user.
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BASICS.
Computer can’t learn itself by the practice.
Note:-
Computer is used in the
Government organization.
Private organization.
Railways.
Airlines.
Weather reports.
Satellite information.
Police stations.
Characteristics of computer:They are six types of characteristics in each computer. They are 1.
Speed.
2.
Storage.
3.
Diligence.
4.
Accuracy.
5.
Versatility.
6.
Automation.
1. Speed:Computer can solve any problems in very high speed. The speed of computer measured in MHz (Mega Hertz) presently moved on GHz (Gaga Hertz). It can pass the results in (Calculates) Nano second (1/1, 00, 00,000).it reads million instructions per second (MIPS). It works faster than human being.
2. Storage:Computer can store unlimited data. Computer stores the data in binary code (0, 1). Americans develop this code. That is ASCII. ASCII stands for American Standard Code for Information and Interchange. ASCII codes are totally 256(0 ----255). 0 – False, 1 – True. Data calculates in bytes. Either 0 or 1 is called as bit. Group of digits i.e., 0’s and 1’s are formed as binary form.
A to Z Alphabets 0 to 9 !@#$%^&*
One character takes in to ---
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Characters Digits Special Characters
8 bits.
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BASICS. 4 bits
---
1 nibble
8 bite
---
1 byte
1024 bytes
---
1 KB {K ilo Byte}
1024 KB
---
1 MB {Mega Byte}
1024 MB
---
1 GB {Giga Byte}
1024
---
1 TB {Tera Byte}
3. Diligence:Computer can’t take rest at all. It can solve the problems in same speed. It can’t suffer from human trails. It can do the all given problems, it can’t leave any problem.
4. Accuracy:Accuracy means Exactness do 100% correctly. Computer can solve the problems 100% correctly. If the data given to the computer is correct it can solve the problems correctly .
5. Versatility:Versatility means doing different types of wor k at the same time. Computer can solve different types of problems in versatile way. It can do the work for any type of programs like equations, scientific calculation & mathematical calculation, accounting calculations formulas etc.
6. Automation:Day to day work done by the computer is called as automation. Meanwhile computer can do the work continuously, until without our intervention.
Types of computers:There are different types of computers, in various sizes and performing different functions. They can broadly be classified into three types according to data. They are
1. Analog computers. 2. Digital computers. 3. Hybrid computers.
1.
Analog computers:-
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BASICS.
Analog Computers.
These computers operate by measuring quantities. They process the information that is physical and continuous in nature. They are special purpose machines mainly used in the field of science.
2.
Digital computers:-
Digital Computers.
These computers operate by counting. They express all quantities in numbers. They accept all data in numerical form and perform calculations on them mathematically. Modern computers based on their applications are classified under digital computers.
3.
Hybrid computers:-
Hybrid Computers.
These computers are a combination of analog and digital computers. They combine the good features of both, e.g. an analog device measures the patient’s heart beat (ECG). These measures are then converted into digital from and digital device checks any abnormality.
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BASICS. They digital computers can further be classified into three types according to size. They are
1. Micro computers. 2. Mini computers. 3. Mainframe computers. 4. Super computers.
1. Micro computers:-
Micro Computers.
These are the smallest and least expensive. They are also known as lap top computers, personal computers (PCs) or business computers. Single person operates a typical microcomputer, hence the name personal computer . Most microcomputers can either operate in a stand-alone mode independently or as intelligent terminals in the network mode.
2. Mini computers:-
Mini Computers.
A popular computer system is the mini-computer, which is a small, general-purpose computer . It can vary in size from a small desktop model to the size of a small filling cabinet. A typical mini system is more expensive that a PC and surpasses it in storage capacity and speed. While most PCs are oriented towards single users, mini systems are usually designed to simultaneously handle the needs of multiple users, i.e., more than one person uses a mini-computer at the same time.
3. Mainframe:-
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BASICS.
Mainframe Computers.
A mainframe is another form of a computer system that is generally more powerful than a typical mini system. Mainframe themselves may vary widely in cost and capability. They are used in large organizations for large-scale jobs.
4. Super computers:-
Super Computers.
At the end of the size and capability scale are the supercomputers. These systems are the largest, fastest and most expensive computer in the world. Such computers are used in scientific and technological research and for applications in defense and weather forecasting systems. Some examples are the CDAC PARAM 10000, CRAY series of computer HEP 15900 series, AMDEL 1400.
Generations of computer:The evaluation of particular period is called as Generation. Computer generations are classified in to 5 types. They are 1.
First generation.
2.
Second generation.
3.
Third generation.
4.
Fourth generation.
5. Fifth generation.
1. First Generation{1946 - 1955}:-
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BASICS. In this generation computers run with the support of vaccume tubes. The data stored in magnetic drums. The computer cost is very high and more expensive, the size of computer is very large, it can take more space, and air condition is must and should. Speed performance in milli seconds 1/1000.
VAccume Tubes.
Magnetic Drums.
2. Second generation {1955 - 1965}:Inthis generation computers run with the support of transistors instead of vaccume tubes. Data stored in magnetic tapes. Decrease the siz & cost. Air condition is must and should, speed performance in Micro Seconds 1/10,00,000.
Transistor.
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BASICS.
Magnetic Tapes.
3. Thired generation {1966 - 1975}:In this generation computers run with the support of IC’s{Integrated Circuits} I.B.M.-360 series is found in this generation. IBM stands for International Business Machine. The speed of computer still in terma of mocro seconds. Data stored in hard disks. Decrease the size & cost when compare to the 1st and 2nd generations. Introducing the operatin systems in this generation.
Integrated Circuits.
Hard Disk.
4. Fourth generation {1975 - 1984};In generation computer run with the support of VLSIC’s{Very Large Scale Integrated Circuits}, micro processor . The speeed of the computer is in nnanoseconds. Data stores in hard disks. Decrease the size & cost when compare to the 1st, 2nd & 3rd generations. In this generation, found printers ,floppies and zip drives. Technology developed in both software & hardware environment.
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BASICS.
Microprocessors.
Hard disks.
Printers.
Floppies.
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BASICS.
Zip drives.
5. Fifth generations {1984 – till today}:In this generation scientists want to develop Artificial Intelligence {A.I}. To make computers function and take decisions almost like a human deing.
Robots.
data operations or functional componts:-
M.M.U {MAIN MEMORY UNIT}
IN PUT OUT PUT
C.U {CONTROL UNIT}
A.L.U {ARITHMETIC AND LOGICAL UNIT}
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BASICS.
c.p.U {CENTRAL (OR) CONTROL PROCESSING UNIT }
Input:-
Keyboard.
Mouse.
Light Pen.
Data given to the system is called ‘in out’. The key board of a computer the best example of an input divice. Any thing typed on the key board will be accepted and will be stored in computer memory for later procesling . input unit is used to estabisn a communication link between computer and people.
c.p.u {central or control processing unit}:central (or) control processing unit or microprocessor. This is worked as mediator between input and output, it will control the parts of the system. Tthis unit processses the data. Meanwhile, the given information (input) is taken and produces the result (output). That’s why, this is called by the name of ‘heart of the computer’. Basic storage device is ‘hard disk’.
m.m.u { MAIN MEMORY UNIT }:The main memory unit is also known as the primary memory unit. The storage space used to store the input data. The user programme and the intemediate results. The information stored in this unit will be available as long as the powersupply is connectd to the computer. If the power is disconnected for any reasan then the all the information will be eraser from the memory and an operation will have to retype. The data once again ofter the power supply is restered in orden to auceid this incanvnience the secondary memory deuice. External memory deuice are used which does not need power all the time. The secandary memory deuices are the wagnetic dwices such of floppy or tape.
C.U{CONTROL UNIT}:This is used to control and coordinate the all parts of the computer. Just like it acts as company manager . The give information is taken from the keyboard and it places into the memory. After that, it separates the information based on data type. If the data is numeric type it sends that information to the relevant component i.e., ALU. It produces the result and it sends that to the C.U. From that part, it sends that information into memory, after that it sends the information directly to the monitor or printer .
A.L.U{ARITHMETIC AND LOGICAL UNIT}:28 January 2011
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BASICS. Arithmetic and logical unit is used to make the calculation and logical operations. It produces the numerical values. Then it will pass the result to C.U.
Output:To view the given information or display the result on the output devices. Basic output device is monitro.
Note:The input, output and secondary units are called as pimery devices.
Outputs produced by the devices:To view the given information or display the result on the output devices. Basic output device is monitor . There are two types of output produced by these divces. There are 1. Soft Copy. 2. Hard copy.
1. Soft Copy:An output on the VDU or stored on magnetic media (Disks OR Tapes).
2. Hard Copy:An outp put produced on a printer or a plotter .
Main memory divides:Main memory dives is the one of the primary memory. Primary memory is one which is a fast memory. Again it contain two types of memories. There are 1.Random Access Memory (RAM). 2.Read Only Memory (ROM).
1.Random Access Memory (RAM):This is a temporary memory. This memory is used to store the data and intermediate resuits while executing the programme. A separate slot will be provide in a computer which is known as RAM’S slot. It is also reffered as rad or write memory because information can be used from a RAN CHID and can also be written into it.
2.Read Only Memory (ROM):This is a permenant memory. We can’t write any thing on ROM. Some information is written by the manufacturing which is necessary for all computers. So, When ever it is needed it will automatically invoked by the computers. Again in this, we are having three types. I.
Programable Read Only Memory(PROM).
II. Erasable Programable Read Only Memory (EPROM.) III. Electrically Erasable Programable Read Only Memory (EEPROM.)
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BASICS. I.programable read only memory (PROM):Which is costly and not used for normal purposes. In this, user programes corverted into micro programmes and storing them into PROM CHIP. Once the chip has been programmed, the recorded information can’t be changed. It is only for reading the stored information. Even if power switched off no effect to the stored information.
II.Erasble programable read only memory (eprom):This is the PROM on which the information erased by placing the EPROM under a special Ultra-Violet Light for a given period of time. So, That the PROM will come to the onotial state and again we can reprogram it.
III.Electrically Erasable Programable Read Only Memory:In this EEPROM instead of Ultra-Violet Rays, the electrical singnals are used to erasa the memory.
Computer environment chart:Computer.
Soft Ware.
Hard Ware.
System
Application
C.P.U, Mouse,
Soft Ware
Soft Ware
Key board and Monitor.
Ms-Dos, MsWindows, Linux and Unix
Packages Ms-Office Pagemaker, Oracle, VB
Languages c, c++ and Java
And Tally Soft Ware:A set of programs is called as ‘Soft Ware’, that we can see nad use enough.
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BASICS. The physical components of the system are called a ‘Hard Ware’, that we can see, work and touch also. Examples of the Hard Ware is C.P.U, Keyboard, Mouse and Monitor.
System Soft Ware:It is co-ordinate and controls the parts of the system, Without this we can’t do any thing. The operating system is called as ‘System Soft Ware’. Examples of tha System Soft Ware is Ms-Dos, Ms-Windows, Linux and Unix.
Application Soft Ware:User has to install it for working purpose. Programmers create this Soft Ware. This is also called ‘Grouping program’. Meanwhile all programs are grouped by one name . either languages or packages create application software. It is again divided into two types.
Packages:This is also software. But the commands are already crated for our working purpose. Ever command has at leat one program. These commands are fixed programs. We can’t modify the options in the ‘Packages’. Examplea of the Packages is MsOffice, Pagemaker, Oracle, VB and Tally.
Languages:The languages define the programs. By this language, we can create software according to our wish. If the software is not working as our wish, we can modify those instructions again and again. Examplex of the Languages is c, c++ and Java. There are three types of languages. There are 1. Machine language. 2. Low level (or) Assembly language. 3. High level language.
List of some devices:INPUT DEVICES
STORAGE DEVICES
OUTPUT DEVICES
Key board Mouse Joystick Light pen Scanner OMR OIS BCR MICR
Hard disk Floppy CD Pen drive Zip drive
Monitor Printer
Key Board:-
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BASICS.
Keyboard.
The keyboard is the most commonly use input device. It resembles the standard typewriter machine (QWERTY keyboard) withsome additional keys.
KEY
FUNCTIONS
Esc F1-F12 (function keys) Tab Caps lock Shift
Depends on the applications, usually used to cancel a command. Used to perform special functions that depend on the software being used. Used to tab on the fore characters. Used for keying in capitalized alphabets. Caps lock off: if pressed simultaneously with a character key, it appears capitalized alphabet. Caps lock on: it reverses the above effect. Also used to input the upper symbols for keys with two symbols or characters on them. Pressed with other key, used to perform commands depend on the software being used. Used to insert the all applications. Used to the space on the one character. Used to execute an instruction or data being keyed Used to erase the character to the left of the cursor position. Used to place the cursor from curent position to starting of the line. Used to place the cursor at end of the current line. Used to place the cursor one page up. Used to place the cursor one page down. Used to insert characters at the current cursor position. Used to delete characters at the current postion. Used tomove the cursor in the direction indicated. Used to activate the numeric keys on the numeric keyboard.
Ctrl, Alt Start Space Bare Enter Back Space Home End Page up Page down Insert Delete Cursor Keys Num lock
Mouse:-
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BASICS.
Mouse.
A mouse is an input device that is used to point and select an option on the VDU(Visual Display Unit). A mouse may have one, two or three duttons. The program that uses the mouse determines the function of each button. Moving the mouse on a flat surface produces a corresponding movement of a pointer on the screen. Left dutton is used to seleting items. Right button is used to editing purpose and displays of selecting items.
Joy stick:-
Joy Stick.
This is normally used for playing games.
Light pen:-
Light Pen.
A light pen is a pointing device that can be used to select an option by simply pointing at it, or drawing figures directly on the screen.
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BASICS. A light pen has a photo- detector at its tip. This detector can detect changes in brightness of the screen. When the pen is pointed at a particular spot on the screen, it records change in drightness instantly and informs the computer about this. The computer can find out the exact spot with this information. Thus, the computer can identify where you are pointing on the screen. Light pen are usefuk for menu-based applications. Instead of moving the mouse around or using a keyboard, the user can select an option by pointig at it. A light pan is also useful for drawing graphics in CAD. An engineeer, architect or a fashion designer can draw directly on the screen with the pen.
Scanner:-
Scanner.
Another input device that is being increasing used is the scanner. Often, there is situation when some information (picture or text) is available on paper and is needed in the computer disk for further enditing. The simplest way would be to take a photograph of the image directly from the source, and convert it into a form that can be saved on the disc and then printed .
Optical mark reader:-
Optical Mark Reader.
It is a device using optical technology, to detect the presence, or absence of mark in a standard position on a form. The presence of the mark is detected due to lesser light being reflected from the mark. This device is generally used for reading answers to questions in a test or a survey.
Optical image scanner:-
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BASICS.
Optical Image Scanner.
This device uses optical technology to capture the image provided to it. It works somewhat like a Xerox machine.
Bar code reader:-
Bar Code Reader.
This device uses optical technology to screen bar code and translates them into meaningful data. A bar code is set of strips of lines signifying certain quantitative and qualitative feature of a product. A bar code can be found on the back cover page of most books.
Magnetic Ink Character Reader:-
Mangnetic Ink Character Reader.
It uses special ink to print characters, which can be read decoded by special magnetic devices.this system is widely used by banks for processing cheques.
Hard disk:-
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BASICS.
Hard Disk.
A hard disk is a storage that contains one or more rigid disks called platters coated with magnetic material sealed in an enclosure. It is most often called a fixed disk as it is placed with in the cadinet of the computer system. The storage capacity of the hard disk is more than a floppy disk. The data is stored in the form of magnetic impulses. It rotates per second 3600 times. The rounded circle is called track. These traks are divided into sectors. Sector is indicated as ‘V’ shape.
Floppy disk:-
Floppy Disk.
A floppy disk is a circular plastic disk coated with magnetic oxide and enclosed with in a square plastic cover. The data or instruction is stored in the form of magnetic impulses. The floppy disks are available in different sizes, but the most commonly used floppy disk are 51/4 and 31/2.
CD:-
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BASICS.
CD.
An optical disk uses optical technology (LASER) to store and retrieve data. The amount of data that can be stored on a single disk is enormous. However, it faces only one drawback and that is, once we recorded, it can’t be modified or removed, but can be read as many times as you wish i.e. WORM (Write Once Read Many Times).
Pen drive:-
Pen Drive.
This is also used for store limited data. This is external device.
Zip drive:-
Zip Drive.
This is also used for store limited data.
Moniter :-
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BASICS.
Moniter.
A visual display unit often called a VDU is a device very similar to the television, used for displaying output. It is not only an output device, but is also referred to as an interactive device. It interactively displays what you key in through the keyboard. The output by VDU is a soft copy. The two different kinds of VDUs available are: 1.
Monochrome or Black and White.
2.
Colour.
There are two different modes od display: Text:-
Where only text can be displayed.
Where text as well as graphical objects can be displayed. Characters are buit up using a combination of picture dots called pixels. The image that appears on the screen is shown by building up of a drawing made of these dots of pixels. Graphics:-
Printers:-
Printers.
A printer is an output device that prints results on paper. The output produced by a printer is called a hard copy.
Printers:Printers can be classified of three types. There are
1. Character Printer. 2. line printer. 3. page printer.
Printers are also classified as two types. There are
4. Impact Printer. 5. Non- Impact Printer. 6. plotter.
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BASICS. In this type of printers printes one character at a time. Character printers Examples are Dot matrix printer.
2.line printer:In this type of printers prints one line of text at a time. Line printer examples are inkjet or deskjet printers.
3.page printer:Inthis type of printers prints a complete page at a time. Page printer examples are laser printer .
4.impact printer:The impact printers used eletronic mechanism to canse hammer or pins to striks a gainst a ribben and paper arrange ment. Dot matatrik, chain and drum printers are examples of impact printers .
5.non-impact printers:The non-impact printers does not have any mechanism to strikc. It user the chemical termal and electronic lacer beam or ink-jerk techology for printer. Non-impact printers normally faster than the impact printers. Non-impact printers examples are lasser printer.
6.plotters:-
Plotters.
These are output devices and are used to produce high resolution graphics and draing by the computers .
Important terms:Secondary memory:Secondary storage memory is a permenant memory but slower than primary memory. Examples of the secondary memory is Floppy disk, Magnetic tape, Magnetic disk and Magnetic drum.
Cache memory:A small high speed memory which is used to increase the speed of processing by making current programmes and data available to the C.P.U.
Operating system:OS is a software, which is an interolase between user of the computer and computer. The examples of the Operating System is Dos, Windows.
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BASICS. Transulators:Which transulates the high level language (or) low level language (Assembly language into machine level language.) There are two types of transulators. There are
1. Compiler. 2.Interpriter.
1. compiler:-. Which converts the whole code at a time into machine language.
2.interpreter:Which converts the code line by line into the user to some language.
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BASICS.
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