Concept of Computers

Introduction

What is a computer?

A computer is a device which can carry out sequences of arithmetic and logical operations automatically with the help of computer programming.

What is a computer system?

A computer system refers to a complete computer that has hardware, operating system and its peripheral equipments. The term can also be used for a group of computers that work together (such as in network).

What are Computer Programmes?

Modern computers follow a generalized set of instructions to perform various functions. These are known as programs. These let the computers to perform a huge range of tasks.

What are examples of devices that use computers as control systems for functioning?

Computers are used in a huge arena of human endeavors and act as a second self to all of us. These act as control systems in a number of household and industrial devices like industrial robots, microwave ovens, remote controls, Smartphone, personal computers etc.

What are indisputable characteristics of a computer?

Speed, accuracy and versatility comprise indisputable characteristics of a computer.  In addition, it also has reliability and storage capacity. These are some of the factors which make it such important parts of our lives.

How computers play as control systems in our daily life?

Computers are used as control systems for a wide variety of industrial and consumer devices. This includes simple special purpose devices like microwave ovens and remote controls, factory devices such as industrial robots and computer-aided design, and also general purpose devices like personal computers and mobile devices such as smart phones. The Internet is run on computers and it connects hundreds of millions of other computers and their users.

Brief History

What are the ancient examples of computers?

Humans have always endeavored to create systems for several kinds of calculations such as astronomical positions and eclipses for calendar and astrological purposes. One oldest example is the Antikythera mechanism, which is believed to be the earliest mechanical analog computer. It was designed to calculate astronomical positions in ancient Greece. Another example is astrolabe, which was invented in the Hellenistic world by Hipparchus.  The astrolabe incorporated a mechanical calendar computer.

Who used the term computer for the first time?

As per Oxford English Dictionary, the term computer was used in 1613 for the first time by an English writer called Richard Braithwait in his book titled “The Yong Mans Gleanings”.  According to the Online Etymology Dictionary, first use of “computer” for a noun i.e. “one who calculates” was in 1640s. However, these uses were for humans. For machine, the term came to be used in 1897.

When was the term “computer” used for the first time in modern sense?

In modern times, some mechanical devices were built to automate long and difficult tasks during Industrial revolution; but none of them was called a computer. In 1936, the principle of the modern computer was proposed by Alan Turing. His seminal paper “On Computable Numbers” has proposed a device called the Universal Computing Machine, which is also called “Turing Machine”. The phrase Programmable Digital Electronic computer was for the first time used in 1945. The first digital electronic calculating machines were developed during World War II.

Why Charles Babbage is considered as the father of the computer?
Charles Babbage, an English mechanical engineer and polymath gave the concept of a programmable computer. He is considered as the “Father of the Computer”. He is considered to be father of computer because he conceptualized and invented the first mechanical computer in the early 19th century.

He created two important things: (1) a difference engine that aided in navigational calculations (2) an analytical engine which used input in the form of punched cards.The Analytical Engine incorporated an Integrated memory, Arithmetic Logic Unit, Control Flow in form of conditional branching and loops which made it the first design for a general purpose computer.

Who gave the first successful demonstration of use of a simplified analytical engine in computing tables in 1888?

The first successful demonstration of the use of a simplified analytical engine in computing tables in 1888 was given by Henry Babbage.

Which was the first example of an electromechanical relay computer?
The Z2, created by a German Engineer Konrad Zuse in 1939, was one of the foremost examples of an electromechanical relay computer.

Which was world’s first fully automatic digital computer?

Konrad Zuse made the Z3, which was the first fully automatic digital and electromechanical programmable computer. It was built with 2000 relays.

Which was the world’s first electronic digital programmable computer?
Colossus was the world’s first electronic digital programmable computer which used a large number of valves.

Basic Knowledge

What are the main components of a computer?

A general purpose computer has five main components viz. memory, mass storage device, input device, output device, Central Processing Unit.

What is memory?

Memory enables the computers to store, at least temporarily, data and programs. All input data and instructions are stored in the memory. There are two types of memory viz. primary and secondary. Primary memory resides within the CPU while the secondary memory is external to it.

What is Mass Storage Device?

A mass storage device allows the computer to permanently retain large amounts of data. Common classic mass storage devices include disk drives and tape drives. Current Mass Storage devices in use include hard disks, USB drives, Memory Cards etc.

What are examples of input devices?

The most usual input devices are a keyboard and mouse. They are used to put in data and instructions to computer.

What are examples of output devices?

The most usual output devices are display screens such as Monitor which are of several types now a days and a printer, or other device that lets us see what the computer has accomplished.

What is Central Processing Unit (CPU)?

A general purpose computer has four main sections: the arithmetic and logic unit (ALU), the control unit, the memory, and the input and output devices (collectively termed I/O). These parts are interconnected by busses, often made of groups of wires. The control unit, ALU, registers, and basic I/O (and often other hardware closely linked with these) is collectively known as a Central Processing Unit (CPU).

Primitive CPUs were comprised of many separate components but since the mid-1970s CPUs have typically been constructed on single integrated circuits called microprocessors. CPU plays the role of a brain in the computer.

What are Hardware and Software Components of Computer?

The components of the computer which we can see and touch are called the hardware components of the computer.  They include devices like keyboard, mouse, printer etc. The set of instructions or programs that make the computer function using the hardware parts are called the software.  We cannot see or touch software.