Wednesday, February 27, 2013

personal Computer very useful


                 A personal computer or PC is a relatively small, inexpensive computer that is designed for use by one person at a time.
      Personal computers first appeared in the late 1970’s. one of the first and most popular personal computers was the apple II, introduced in 1977.
     Today, PCs can be desktop PCs, laptops, or tablets. Users have access to a wide range or commercial and free software which is easily installed.
Apple II Computer(1977)
                 In fact, now more than 10,000 application programs are available for use on personal computers. They include word processing programs, spreadsheet programs, database programs, and communication programs .
     Word processing programs are used to type, correct, rearrange, or delete text in letters, memos, reports, and school assignments. Database programs allow a computer to store large amounts of data in a systematic way. Communication programs connect a personal computer to other computers.

BYTE


Before discussing what a byte is, you must know what a ‘bit’ is. A bit is a unit, that at all times, has one of two possible values. The two values are ‘on’ and ‘off’. Computer programmers use the numbers 0 and 1 to represent these two values. 0 stands for ‘off’, and 1 stands for ‘on’. Thus, a bit that is off has the value o and a bits froms a bits are grouped into bytes to separate one piece of information from the next. Bytes are used to measure the amount of information a device can store. 


Integrated Circuit from a Microchip.

Tuesday, February 26, 2013

First Commercial Computer


The term UNIVAC stands for universal automatic computer, UNIVAC 1 was the first commercial computer made in the US, and the first one designed for business and administrative purposes. In 1952, it successfully predicted, on television, the result of the presidential Election of the US.
UNIVAC I - Operator Console
(Museum of Science, Boston, MA)
More......

Why is the IC important?
The invention of the IC is one of the most important innovations in modern technology. The term IC stands for integrated circuit.
An IC is a very, very tiny piece of silicon which is made up of thousands of transistors. A transistor is a device composed of semiconductor material that amplifies a signal, or open or closes a circuit. It ia an important component in modern electronics.
Integrated circuits can be produced cheaply, which means that the appliances using them, like computers, become cheaper too. Moreover, since ICs are very tiny, equipment using ICs also became  smaller have truly revolutionized the world of electronics.



Brain of the computer
The brain of computer is its CPU or central processing unit. It is made up of millions of electronic circuits. Like your brain, the CPU controls information. And tells the computer what to do.


Sunday, February 24, 2013

CHARLES BABBAGE IMPORTANT IN THE HISTORY OF COMPUTER

Charles Babbage




Charles Babbage was a British mathematician, who is often called ‘The father of computing’. He designed the first automatic computing engines.
In Babbage’s time, mathematical table were generated by team of mathematicians, and mistake were common. Babbage dreamed of removing the human element from these calculations. He designed the first computer, a machine he called ‘the difference engine’, in 1822. It was the size of a house, could store a program, and was powered by stream.
Babbage’s stream-powered analytical engine, outlined the basic element of a modern general purpose computer and was a break though concept.
Babbage invented computer but failed to build them, and the first complete babbage engine was completed in London 153 years after it was designed.


Part of  Babbage's Difference Engine


Hybrid computer   

Computers that accept analog signals and convert them into a digital form are called hybrid computers, because they have the features of both analog and digital computers.

MICROCHIP


Robert Noyce
Jack Kilby
            

Microchips

             
A microchip is asset of interconnected electronic components such as transistors and resistors that are etched or imprinted on tiny chip.
This chip is made of a semiconducting material. Such as silicon or germanium. Earliest, these individual electronic components were set out and linked on a circuit board. As technology advanced, circuits became smaller and smaller. The first microchip invented is credited jointly to Robert Noyce and Jack Kilby in 1958. The microchip is at the heart of many electronic appliances known today.


The Antikythera
The antikythera was a thin device made of bronze which was used to calculate the movement of the stars and planets in astronomy. This ancient mechanical calculator was discovered about 100 years ago in a shipwreck. It is believed to have been used by the Ancient Greeks.



Saturday, February 23, 2013

What are the parts of a computer?



A computer is really a system of many parts working together. The system unit is the core of a computer system. Inside this box are many electronic components that process information. The most important of these components is the central processing unit, called the CPU, or microprocessor. It acts as the ‘brain’ of your computer. Another component is random access memory or RAM, which temporarily stores information that the CPU uses, while the computer is on.
                           Your computer is also has a mouse which is a small device used to point to, and select item on your computer screen. A keyboard is used mainly for typing text into your computer, then there is a monitor which displays information in visual form, using text and graphics.
To connect your computer to the internet, you need a modem. A modem is a device that sends and receives computer information over a telephone line, or high-speed cable.

First hidden sight

A webcam is essentially just a camera that is connected to a computer, either directly or by wireless.
In 1991, the first webcam was set up at Cambridge University. Its sole purpose was to monitor a particular coffee marker so as to avoid wasted trips to an empty pot.

The first message

 Do you know what the first message on the internet was? It was ‘LOG’. The user was trying to type the word ‘log in’ , but the network crashed after the first word! It was sent by Leonard Kleinrock on Oct. 29th, 1969.

Thursday, February 21, 2013

Why is hardware different from software?



Hardware in a computer is any physical device, something that you are able to touch. For example, computer monitors and a computer’s mouse are all hardware.

Hardware is usually enclosed in a case or chassis. Software, on the other hand, is a collection of instructions and codes installed into the computer that cannot be touched. For example, an internet browser and the internet itself constitute software.   

Software can be divided into two groups- system software for operating systems, and application software like word processing, and computer games.

To sum up, we can say that a CD or pen drive is hardware, while the program which is loaded in the CD or pen drive is software.
 

What are the differences between analog and digital technologies?



In analog technology, a wave is recorded or used in its original form. For example, in an analog tape recorder, a signal is taken straight from the microphone, and laid onto tape.
In digital technology, the analog wave is turned into numbers that are stored in the digital device. To hear the music, the numbers are turned into a voltage wave that resembles the original wave.
The big advantage of digital technology is that the recording does not become distorted with time. As long as the numbers can be read, you will always get exactly the same wave, and the same sound.
An Analog Computer AKAT-1
An Analog computer AKAT-1


Sound Cards
 Sound cards or audio cards enable the input and output of audio signals to, and from a computer. A computer with a sound card can produce 3-D audio, for surround sound playback for DVDs. It can also capture and record sound from external sources too.