Computer Fundamental Basic Notes

Computer Fundamental 

Introduction: - The term Computer is derived from the word ‘compute’, which means to calculate. A computer is an electronic machine, devise for performing calculations and controlling operations that can be expressed either in logical or numerical terms.

History of  Computer:- History of Computer can be considered from arise of human culture as person known the calculation they used something for this purpose like, pebbles stone etc. but as a device Roman’s abacus is first device  used in B.C for calculation. In A.D various mechanical devices were invented for the calculation like Pascaline by Blaise Pascal, Joseph jacquard invented loom that is ‘programmed’ using punched cards, Charles Babbage invented two machines Analytical engine and Difference engine and Hollerith’s Census Machines (Tabulating machine). John Mauchely and Presper Eckert make the Electronic Numeric Integrator and Calculation (ENIAC) First general purpose, digital electronic Computer used to compute a ballistic firing.

Full form of Computer: -
 C - Common

 O - Oriented  

 M - Machine 

 P - Particularly 

 U - Used for 

 T - Trade and 

 E - Education 

 R - Research 

Note:- Mr. Charls Babbage was the father of Computer.

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 Characteristics of a Computer:- 

1. Speed: - Computer works at an amazing speed without any mistakes. Speed of a computer is measured in millisecond (10-3 second) or nanoseconds (10-9 second).

2. Reliability: - Computer is more reliable than a human being as it never gets bored of the repetitive tasks and never gets tired.

3. Storage Capacity: - Computer can store large amount of data in its memory, in the form of documents, graphics, sounds etc.

4. Never gets Tired: - Computer can operate for long hours without taking rest, with its accuracy in tact.

5. Reduction in Paper work: -With use of computer, large amount of paper wastage is prevented in any organization. Computer has reduced a lot of office work too.

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        Application of Computers:- 

1. Banks:-With computerization and networking of a large number of banks, the customers now have the facility of ATM.

2. Education: - Computer aided learning and teaching is changing the entire spectrum of our education system.

3. Business: - Computer has helped in improving business activities through the world. Computer is use in office for maintaining sales record, stock control, preparing salary etc.

4. Criminal Identification: - Computer can create photographs of criminal of criminals resembling them. This helps C.B.I staff to arrest criminals.

5. Airlines/ Railways Reservation: - These days’ computers are being used for railway/bus/airline reservation.

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Classification of Computers 

A computer has been categorized in the following parts likewise…. 

•  Analog Computer 
• Digital computer 
• Hybrid Computer

1. Analog Computers: - Analog Computer are used mostly in Medical Science. This very kind of computer works on continuous data values, for e.g. if you have to calculate the pressure or something similar then kind of technology having will be useful. 

2. Digital Computer: - Digital computers are the most commonly used computer on a digital technique which is widely used and preferred now-a-days. This kind of computers uses micro processor technology which quite digital and able to calculate and execute million of instruction within a second. This also comes under kind of categories as we can see downloads… 

• Micro Computer: - A micro computer is a small, low cost digital computer, which usually consists of a micro processor, a storage unit, and an input channel and \output channel. 

•  Mini Computer: - A mini computer is a small digital computer, which normally is able to process and store less data then a main frame but more than a micro computer. 

•  Main Frame computer: - A main frame is an ultra high performance computer made for high volume, processor-intensive computing. It consists of a high and computer processor with related peripheral devices. 

•  Super Computer: - Super Computers are the special purpose machine, which are specially design to maximize the number of FLOPS (Floating Point Operation per Second). A super computer has the highest processing speed at a given time for solving scientific and engineering problems. 

3. Hybrid Computer: - Hybrid computer incorporate the measuring features of an analog computer and counting features of a digital computer. 

-: Computer Components:-  

1. Power Switch:- It is the switch button which is used to start the computer system and you can even shut down the system by pressing and holing it. 

2. Reset Button:- It is used to restart the computer system in case if during run time you need any start. 

3. Front USB port,  Mic & headphone slot:- This very slot are used to accept any USBs, Mic & Headphones. The slot of Mic & Headphone are called jack slot. It is located at the front panel of the CPU cabinet. 

4. Indicator light:-  It is the single light which It is the single light which confirm that system is still running and when you shut this down then it gets automatically turn off. 

5. Power Supply Socket:- This slot is used to supply the power to the CPU. In this Connect a power cable through the power is supply to SMPS and that reaches every part of  the necessary component. 

6. Keyboard Socket:- This slot is used to connect the keyboard to the computer system.

7. Mouse Socket:- This very slot is used to connect the mouse to the computer system. 

8. Parallel Port:- This is used to connect any parallel device to the computer system. This parallel device may printer or something similar. 

9. VGA Port:- This port is used to connect the visual Display unit like monitors.

10. Network slot:- This slot is used to connect to any network through the network cable.

11. Motherboard:- This is the main component of the computer system where all electronic component integrated together and support to make computer system is run is situated and set there like RAM,ROM, Processor and many more. 

12. Fan:- This is set inside and set fan face to outside so that whatever heat generated by the CPU may get colder.

13. Display Adapter Card:- This is adapter card used to link Monitor to CPU. Whatever task is being performed in CPU can be viewed and displayed to monitor with the help of this. 

14. Expansion Slots:- These slot is used to connect any extra device or interface with the computer system you want to connect. 

 Input Devices: - Input devices are used to input data and instructions into the computer 

1. Keyboard: - A keyboard is the main input device used to input data and instructions into the computer.  There are four main types of keys on the keyboard: 

There are four main types of keys on the keyboard:

1.  Typing keypad: - It includes all character symbols (A-z). 
2.  Numeric key: - It includes number keys from 0 to 9 
3. Function key: - There are 12 keys, from F1 to F12, for performing special tasks. 
4.  Editing keys: - It comprises of insert, delete, backspace, page up, page down keys, etc. 

2. Mouse: - The mouse is the most used input device that lets you select and move items on the screen. 

The mouse left button is used most of the time. A single click of this button selects an item and then clicking again activates the application. The right-click often displays a list of commands on the screen. You can also gain access to Property settings, with right click.

3. Joystick: - A joystick is an input device normally used in Video Parlors for playing games. It has a moving stick with some push buttons. The angle or direction of the stick movement is send to the computer as the input. 

4. Scanner: - It is an input device that optically scans text, images and objects. The scanned data is then converted into a digital image and is displayed on the computer monitor. 

5. Microphone: - It is an input device used to record and store voice or any other sound into a computer, generally as a .wav file. Microphone is commonly used in video conferencing and speech recognition programs.

6. Bar Code Reader: - It is an input device used for reading barcodes on various surface. A bar code reader consists of a light source, a lens and a light sensor for translating optical impulses into electrical signals.

7. OCR (Optical Character Reader):- It’s a device which detects alphanumeric characters printed or written on a paper. The text which to be scanned is illuminated by a low frequency light source. The light is absorbed by the dark areas but reflected from the bright areas. The reflected light is received by the photocells.

8. MICR (Magnetic Ink Character Reader/Recognizer): - It is kind of input device which is used to read magnetic characters from a page like on a bank cheque some magnetic characters are used which can only be read by MICR.

9.Track Ball:- 

10. Other Input Devices are Light Pen and Web Cam etc. 

Output Device: - It is a unit which communicates from machine to man with the help of V.D.U. (Visual Display Unit) and printers. 

1. VDU (Visual Display Unit) Monitor:- This is an output Device. There are two types of the soft output device, Audio Output device for eg Visual Output devices. VDU is a Visual Soft Output device and used for the getting soft Visual Output on screen It measured diagonally from one corner of the screen to the opposite corner. VDU can be categorized into two types on the basis of technology the first one is CRT and second is LCD. The details are as under.

1. CRT (Cathode Ray Tube): - This is television like screen where the results of a computer’s tasks are displayed In this technology Cathode Ray falls on florescence screen and by deflecting rays make picture. There are two types nof CRT’s.
• Monochrome: - Also called black and white.
•  Color: - It has three different phosphors which emit red, green and blue light respectively and due to the RGB color picture appears in colored view. 
2. LCD (Liquid Crystal Display): - This VDU is thin; flat and having light modulating technology. It is of two types: 
• TFT (Thin Film Transistor) It is a variant of LCD and makes matrix but not self lighting. 
•  LED (Light Emitting Diode) It is self back light emitting technology; picture quality is better. 

2. Printers: - A printer is a peripheral device used for printing the output on paper or any other printable media. The printed information on the paper is called Hard Copy. Printers are of two types.

1.  Impact Printers 
2.  Non-impact Printers 

1. Impact Printers: - Impact printers print by the impact of dot wires on the paper. They are also called character printers. Impact Printers are classified as follow.

1.  Daisy wheel printers: - These printers have good letter formation, but cannot produce graphics. They produce letter-quality documents. The range of speed of these printers varies from 60 cps to 120 cps (character per second). 


2.  Dot-Matrix Printer: - They are the only impact printers in use nowadays. As they are noisy and do not have good printing quality, they are losing popularity. Besides text, they are capable of printing charts and graphics. The speed of dot matrix ranges from 50 to 400 cps. 

2. Non Impact Printers: - Non Impact printers do not strike against the linked ribbon or paper on which they are printing. The only thing that touches the paper at all is the ink that is used, Non Impact printers have become. These are as follow:

1. Inkjet Printers: - Inkjet printers are non-impact character printers based on a relatively new  technology. They print characters by spraying small drops of ink onto paper. Inkjet printers produce high quality output with presentable features. 
2. Laser Printers: -provide highest quality of text and graphics printers process and store the entire page before printing and are also known as page printers. The laser printer can print 5-24 pages of text per minute and their resolution ranges from 400 to 1200 dpi. They are faster and expensive than impact printers. 

3. Plotter: - Plotter is an output device that is used to produce graphical output on papers. It uses single color or multi color pens to draw pictures as blue print etc. Plotter is used to print the maps and architecture of infrastructure. It is used in the engineering applications.

4. Speakers: - Speakers are the output devices to play sound. They may be built into the system unit or connected with cables. Through them we can listen to music and sound effects from the computer.

5. Projector:- Projector is an output device. It is a part of computer hardware. Which is used on white screen.On which pictures or videos of some kind are shown.