Categories: Computers & Internet

INTRO TO COMPUTER: In this our technolgy age everyone should read this

Summary:

A computer can be described as an electronic calculating device that accepts raw data as input, processes it and produces meaningful information i.e. output as result.
A computer system is made up of both hardware and software components.
Hardware consists of the physical components of a computer system like input devices, output devices, processing device (CPU) and the storage device.
Software represents the set of programs and instructions that govern the operation of a computer system.
A computer is fast, accurate, versatile, reliable, diligent, and has high speed.
The need for counting and simple computations has led to the development of several computing devices like Abacus, Napier’s Bones, Slide Rule, Blaise Pascal’s Adding Machine, Stepped Reckoner, Punch Card System, Hollerith’s Machine etc.
The evolution of computers can be divided into five generations. Each generation represents technological evolutions over the period of time.
A computer has four functional units Input unit, output unit, central processing unit (CPU) and secondary storage unit.
Input unit is used to provide data, information and instructions to the computer so that it can perform processing on data/information according to the instructions given by the user.
Examples of input devices are include keyboard, mouse, joystick, scanner etc.
Output devices are used to display the result of the processing done by CPU on the input provided by the user.
Examples of output devices are monitor, printer, plotter, speaker etc.
Printer is an output device that is used to get the hard copy of the output in the form of printed papers.
Printers are of two types – impact printers and non-impact printers.
Impact use electromechanical mechanism which makes mark on the paper by physically striking a head or a needle against an ink ribbon.
Dot matrix printers, Daisy wheel printers and Drum printers are examples of impact printers.
Non-impact printers do not make a striking or hitting action on a ribbon to print. They use thermal, electrostatic chemical, laser beam and ink jet technologies for printing on paper.
Inkjet and laser printers are examples of non-impact printers.
They are used to create high resolution graphs, images charts, blueprints, maps, circuit diagram and other line based diagrams.
There are two kinds of plotter- Drum plotter and Flat-bed plotter.
CPU is referred to as the brain and heart of the computer system which is responsible for all the processing done on the data entered by using input device.
CPU consists of three units Control Unit (CU), Arithmetic & Logical Unit (ALU) and Main/Primary storage unit.
Control Unit is responsible for interpreting the instructions provided by the user and directing the sequence of operations accordingly.
ALU performs arithmetic and logical operations on the data. It performs four basic mathematical operations i.e., addition, subtraction, multiplication and division, three comparative or logical operations i.e., ‘greater than’, ‘less than’, ‘equals to’ to compare numbers, letters or special characters between data items.
Main memory holds instructions and data currently being processed by the CPU, the intermediate results produced during the course of calculations and recently processed data.
Main memory is of two kinds Random Access Memory (RAM) & Read Only Memory (ROM).
Random Access Memory is a volatile memory and temporarily holds software, programs and instructions before and after processing.
Read Only Memory is non-volatile memory whose contents are not lost even after the loss of electric power. It contains startup instructions.
Secondary memory is also known as external memory or auxiliary memory, and is required to supplement the limited capacity and volatile characteristics of primary memory.
A Computer has few limitations like they don’t have IQ, they don’t have emotions, they lack decision making power etc.
Computers play a vital role in every sphere of our life like education, home, entertainment, communication, research, banking, medicine and health and so on.
On the basis of purpose computers can be divided into two categories – General Purpose Computers and Special Purpose Computers.
On the basis of technology used by them, computers can be divided into three categories i.e. Analog, Digital and Hybrid computer.
On the basis of size and capacity, computers are of four kinds – super computers, mainframe computer, minicomputer and microcomputer.