BASIC CONCEPTS OF COMPUTERS P REPARED B Y : B AJAJ C OACHING C ENTER R OHTAK BCC COM

C OMPUTER The word computer comes from the word “compute”, which means, “to calculate” Thereby, a computer is an electronic device that can perform arithmetic operations at high speed A computer is also called a data processor because it can store, process, and retrieve data whenever desired Bajaj Coaching Center,ROHTAK

D ATA P ROCESSING The activity of processing data using a computer is called data processing Data Capture Data Manipulate Data Output Results Information Data is raw material used as input and information is processed data obtained as output of data processing Bajaj Coaching Center,ROHTAK

E VOLUTION OF C OMPUTERS Blaise Pascal invented the first mechanical adding machine in 1642 Charles Babbage is considered to be the father of modern digital computers He designed “Difference Engine” in 1822 He designed a fully automatic analytical engine in 1842 for performing basic arithmetic functions His efforts established a number of principles that are fundamental to the design of any digital computer Bajaj Coaching Center,ROHTAK

S OME W ELL K NOWN E ARLY C OMPUTERS The Mark I Computer ( ) The Atanasoff-Berry Computer ( ) The ENIAC ( ) The EDVAC ( ) The EDSAC ( ) Manchester Mark I (1948) The UNIVAC I (1951) Bajaj Coaching Center,ROHTAK

C OMPUTER G ENERATIONS “ Generation ” in computer talk is a step in technology. It provides a framework for the growth of computer industry. Originally it was used to distinguish between various hardware technologies, but now it has been extended to include both hardware and software Till today, there are five computer generations Bajaj Coaching Center,ROHTAK

First generation computer Period : 1945 – 1956 Inviter : Lee de Forest Main processing device : Vacuum tubes Bajaj Coaching Center,ROHTAK

Vacuum tubes Bajaj Coaching Center,ROHTAK

Punched curds Bajaj Coaching Center,ROHTAK

Large punched cards Bajaj Coaching Center,ROHTAK

. First generation computer Advantages :. It was only electronic device. First device to hold memory Disadvantages :. Too bulky i.e. large in size. Vacuum tubes burn frequently. They were producing heat. Maintenance problems Bajaj Coaching Center,ROHTAK

Too bulky i.e. large in size Bajaj Coaching Center,ROHTAK

Vacuum tubes burn frequently Bajaj Coaching Center,ROHTAK

Maintenance problems Bajaj Coaching Center,ROHTAK

. Second generation computer Period : 1956 – 1963 Inviter : William Shockley Main processing device : Transistor Storage media : Magnetic disc Bajaj Coaching Center,ROHTAK

Transistor 1 2 Bajaj Coaching Center,ROHTAK

Second generation computer Advantages :. Size reduced considerably. The very fast. Very much reliable Disadvantages :. They over heated quickly. Maintenance problems Bajaj Coaching Center,ROHTAK

Third generation computer Period : 1964 – 1971 Inviter : Jack Kilby Robert Noyce Main processing device : IC (integrated circuit) Storage media : Floppies Bajaj Coaching Center,ROHTAK

IC (integrated circuit) Bajaj Coaching Center,ROHTAK

Third generation computer Advantages :. ICs are very small in size. Improved performance. Production cost cheap Disadvantages :. ICs are sophisticated Bajaj Coaching Center,ROHTAK

. Fourth generation computer Period : 1971– present Inviter : Ted Hoff Main processing device : ICs with VLSI (Very Large Scale Integration) Storage media : Floppies, CDs. Bajaj Coaching Center,ROHTAK

ICs with VLSI (Very Large Scale Integration) Bajaj Coaching Center,ROHTAK

. Fifth generation computer Period : present and beyond Main processing device : ICs with parallel processing Storage media : Video disks Advantages :. Artificial intelligence. Expert system Bajaj Coaching Center,ROHTAK

. First generation computer. Second generation computer. Third generation computer. Fourth generation computer. Fifth generation computer Vacuum tubesTransistors ICs ICs with VLSI ICs with parallel processing Bajaj Coaching Center,ROHTAK

Computer is a group of electronic devices used to process the data. The characteristics of a computer are: 4. Accuracy 5. Automation 6. Functionality 7. Tirelessness 1. Speed 2. Reliability 3. Memory capacity Bajaj Coaching Center,ROHTAK

1.Speed: computer process the data at an unimaginable speed. The speed of the computer ranges up to Nano seconds. 2. Reliability: The next important characteristic of a computer is its reliability. we can always rely on the information given by a computer. 3. Memory capacity: The memory capacity of a computer is measured in in bits and bytes. Large amount of the data can be stored in computer and retrieved. Memory capacity of the computer ranges in Giga bytes. Bajaj Coaching Center,ROHTAK

4. Accuracy: Accuracy of the computer is very high it performs calculation with greater accuracy in less time. 5. Automation: a computer allows automation for any process designed in the from of a program. A program can be executed any number of times to repeat the process. Bajaj Coaching Center,ROHTAK

6. functionality: computer can performs many kinds of jobs. They not process the data but also can be Used for plying music, movies, and printing jobs. It finds its applications in all most all the fields. 7. Tirelessness: A computer never gate tired. Bajaj Coaching Center,ROHTAK