A computer is an electromechanical device that takes raw data as input, processes the raw data with control of set of instructions and gives the desired result. It can process both arithmetic and logical calculations.
The physical parts that make up a computer i.e. central processing unit, input, output, and memory are called hardware. Set of Programs are called software. Peripherals are any hardware device connected to a computer, any part of the computer outside the CPU and working memory. For ex. keyboards, the mouse, monitors, printers, scanners, disk and tape drives, microphones, speakers, joysticks, plotters, and cameras.
Evolution of Computer Technology
The origin took place in the 19th century.
The ABACUS, the first computer in the world, was used to perform simple calculations
In the 17th century, a scientist named Pascal developed Pascaline to perform mathematical calculations.
This machine comprised of a number of gears.
Charles Babbage wrote on the use of logic and loops in process execution. On the basis of which he envisaged Analytical Engine and Difference Engine.
George Boolean developed the famous Boolean algebra based on binary numbers.
De Morgan put forward De Morgan’s Theorems theorem on logic gates.
Lady Ada was the first computer programmer.
The real application of computers began in the late fifties.
Advantages of Computer
High accuracy
Speed
Large storage capacity
Graphical User Interface
Portability
Platform independent
Economical
Generations of Computers
First Generation
Bulky in size.
Able to execute hundreds of instructions per second
Expensive
Used vacuum tubes as their main components.
Machine language was used
Example EDVAC, UNIVAC etc.
Second Generation
Smaller in size than first generation computers
Capable of executing thousands of instructions per second
Transistors were used
Assembly language was used
Example, PDP (Programmed data processor), PDP1 etc.
Third Generation
More advanced
Used Integrated Circuits
Contained thousands of components per circuit
Cheaper than second-generation computers
Languages used were BASIC, COBOL etc.
Example IBM 307 Series, PDP II etc.
Fourth Generation
Used large scale integrated circuits called microprocessors or chips
Less costly as compared to the third generation computers
Able to execute millions of instructions per second
Languages used in this generation are C++, SQL etc.
Example CRAY 2, IBM 3090/600 Series
Fifth Generation
Work on artificial languages (AI) like LISP, PROLOG etc.
Use super/ultra large-scale integrated circuits
Execute billions of instructions per second
Example, Laptops, Palmtops, PDA (Personal Digital Assistant) etc.
Types of Computers
Analog Computers
Processes Analog Signals which are continuous signals; example: sine wave.
Analog quantities are based on decimal number systems; examples: slide rule, ABACUS etc.
Digital Computers
Process digital signals which are discrete signals with two states 0 and 1.
Batch Processing
Computer acts as a ‘stand-alone’ unit
Available for a single user
Number of programs can be executed simultaneously
They have to stand in queue
The given information and data broadly covers all the basics of the computer knowledge that will stimulate your preparation level. Stay cool, stay focused and work hard!
