Introduction of computer
Introduction to Computer
In the modern era, computers are an essential part of our everyday existence. That means computers are present in almost every field, making our day-to-day tasks easier and faster. Nowadays, computers can be seen in banks, shops, schools, hospitals, railways, and many more places, including our home.
History of Computer
The term 'Computer' was first introduced in 1640 and referred to as 'one who calculates'. It was derived from the Latin word 'computare', which meant 'to calculate'. In 1897, it was known as the 'calculating machine'. Later in 1945, the term 'computer' was introduced as 'programmable digital electronic computer, which is now called a 'computer'.
When the computers were introduced, they were large and could fill an entire room. Some computers were operated using large-sized vacuum tubes. In 1833, Charles Babbage (known as the father of the computer) invented an early calculator, which was named as the 'difference engine'. Later in 1837, he introduced the first mechanical, general-purpose computer 'Analytical Engine'. Over time, computers became powerful in performance and small in size.
Generations of Computer
There are five generations of the computer, which can be classified as below:
First Generation (1946 - 1959): During the first generation, computers were based on electronic valves (Vacuum Tubes). Some popular computers of first-generation are ENIAC, EDVAC, UNIVAC, etc.
Second Generation (1959 - 1965): During the second generation, computers were based on Transistors. Some popular computers of second-generation are IBM 1400, IBM 1620, IBM 7000 series, etc.
Third Generation (1965 - 1971): During the third generation, computers were based on Integrated Circuits (ICs). Some popular computers of the third generation are IBM 360, IBM 370, PDP, etc.
Fourth Generation (1971 - 1980): During the fourth generation, computers were based on very large scale integrated (VLSI) circuits. Some popular computers of fourth-generation are STAR 1000, CRAY-1, CRAY-X-MP, DEC 10, etc.
Fifth Generation (1980 - Present): The fifth generation is still ongoing. The computers are based on multiple technologies, such as ultra large scale integration (ULSI), artificial intelligence (AI), and parallel processing hardware. The fifth generation of computers includes Desktop, Laptop, NoteBook, etc.
Computer Software and Hardware
Software
Computer software is a group of instructions or programs that instructs the computer system to work accordingly. There are mainly two types of software:
System Software: System software help establish communication between hardware components so that the user can interact with the computer. These types of software are necessary for the computer to operate correctly. They provide an interface to run additional third party programs or utility tools. Operating systems, drivers, utility software, and firmware are typical examples of the system software.
Application Software: Application software is designed to help users to perform specific tasks, such as online surfing, setting the alarm, listening to music, playing videos, photo designing, editing, etc. This type of software mostly runs in the frontend and allows end-users to work on. Web browsers, Photoshop software, multimedia software and word processors are the example of the application software.
Hardware
The physical parts attached to a computer that form a whole computer are called hardware or hardware components. There can be different types of hardware, depending on the structure. Some most common hardware are mouse, keyboard, monitor, printer, etc. These are the parts that can be seen and touched by humans.
Basic Parts of Computer
Input Unit: Input Units or devices are used to input the data or instructions into the computers. Some most common input devices are mouse and keyword.
Output Unit: Output Units or devices are used to provide output to the user in the desired format. The most popular examples of output devices are the monitor and the printer.
Control Unit: As its name states, this unit is primarily used to control all the computer functions and functionalities. All the components or devices attached to a computer interact with each other through the control unit. In short, the control unit is referred to as 'CU'
Arithmetic Logic Unit: The arithmetic logic unit helps perform all the computer system's arithmetic and logical operations. In short, the arithmetic logic unit is referred to as 'ALU'.
Memory: Memory is used to store all the input data, instructions, and output data. Memory usually has two types: Primary Memory and Secondary Memory. The memory found inside the CPU is called the primary memory, whereas the memory that is not the integral part of the CPU is called secondary memory.
Computer : is an electronic device that operates (works)
A computer is an electronic machine that processes raw data to give information as output.
all of programs stored in its own memory unit.
A computer is an electronic machine that processes raw data to give information as output.
An electronic device that accepts data as input,
and transforms it under the influence of a set of special instructions called Programs, to produce the desired output
(referred to as Information).
Explanations;
A computer is described as an electronic device because; it is made up of electronic components and uses electric energy
(such as electricity) to operate.
A computer has an internal memory,
which stores data & instructions temporarily awaiting processing,
and even holds the intermediate result
(information) before it is communicated to the recipients through the Output devices.
It works on the data using the instructions issued, means that,
the computer cannot do any useful job on its own.
It can only work as per the set of instructions issued.
It works on the data using the instructions issued,
means that, the computer cannot do any useful job on its own.
It can only work as per the set of instructions issued.Program:
A computer Program is a set of related instructions written in the
language of the computer & is used to make the computer perform a specific task (or, to direct the computer on what to do).
A set of related instructions which specify how the data is to be processed.
A set of instructions used to guide a computer through a process.
Data:
Is a collection of raw facts, figures or instructions that do not have much meaning to the user.
Data may be in form of numbers, alphabets/letters or symbols, and can be processed to produce information.a).
Digital (discrete) data:
Digital data is discrete in nature.
It must be represented in form of numbers, alphabets or symbols for it to be processed by a computer.
Digital data is obtained by counting. E.g. 1, 2, 3 …
TYPES OF DATA.
There are two types/forms of data:b). Analogue (continuous) data:
Analogue data is continuous in nature.
It must be represented in physical nature in order to be processed by the computer.
Analogue data is obtained by measurement. E.g. Pressure, Temperature, Humidity,
Lengths or currents, etc. The output is in form of smooth graphs from which the data can be read.Data Processing:
Data Processing:
It is the process of collecting all items of data together & converting them into information.
Processing refers to the way the data is manipulated (or handled) to turn it into information.
The processing may involve calculation,
comparison or any other logic to produce the required result.
The processing of the data usually results in some meaningful information being produced.
Information:
is the data which has been refined,
summarized & manipulated in the way you want it,
or into a more meaningful form for decision-making.
The information must be accurate, timely, complete and relevant.
Characteristics / Features of a Computer.
Before 20th century, most information was processed manually or by use of simple machines.
Today, millions of people are using computers in offices and at home to produce and store all types of information
1. Speed.
Computers operate at very high speeds, and can perform very many functions within a very short time.
They can perform a much complicated task much faster than a human being.
The speed of a computer is measured in Fractions of seconds.
Millisecond - a thousandth of a second (10-3)
Microsecond - a millionth of a second (10-6)
Nanosecond - a thousand millionth of a second (10-9)
Picosecond - a million millionth of a second (10-12)
The speed of a computer is usually linked to the technology used to build it.
a). 1st Generation computers (1940s & early 1950s).
• The computers were built using Vacuum tubes, and the speed was measured in Milliseconds.
E.g., a computer could perform 5,000 additions & 300 multiplications per second.
b). 2nd Generation computers (1950s & early 1960s).
Were built using Transistors. Their operation speeds increased & were measured in Microseconds.
E.g., a computer could perform 1 million additions per second.
CLASSIFICATION OF COMPUTERS
Computer exist in defferent sizes, weight and shapes
The major ways in which computers are classified are
i) Classification according to Functionality
In this category,
computers are categorised ccording to the way they process data and kind of data a computer can process.
Example of this data are,
a) Analog Data
b) Digital data
ii) Classification according to the purpose
iii) Classification according to physical size
iii) classification according to functionality
Analog computer
Analog computer measures and answer the questions by the method of “HOW MUCH”.
The input data is not a number infect a physical quantity like temp, pressure, speed, velocity.
Signals are continuous of (0 to 10 V)
Accuracy 1% Approximately
High speed
Output is continuous
Time is wasted in transmission time
DIGITAL COMPUTERS
Digital computer counts and answer the questions by the method of “HOW Many”.
The input data is represented by a number. These are used for the logical and arithmetic operations.
Signals are two level of (0 V or 5 V)
Accuracy unlimited
low speed sequential as well as parallel processing
Output is continuous but obtain when computation is completed.
MICRO COMPUTERS
Micro computer are the smallest computer system. There size range from calculator to desktop size.
Its CPU is microprocessor. It also known as Grand child Computer.
Application : - personal computer, Multi user system, offices.
MINI COMPUTERS
These are also small general purpose system.
They are generally more powerful and most useful as compared to micro computer.
Mini computer are also known as mid range computer or Child computer.
Application :- Departmental systems, Network Servers, work group system.
MAINFRAME COMPUTERS
Mainframe computers are those computers that offer faster processing and grater storage area.
The word “main frame” comes from the metal frames. It is also known as Father computer.
Application – Host computer, Central data base server.
SUPER COMPUTERS
Super computer are those computer which are designed for scientific job like whether
forecasting and artificial intelligence etc.
They are fastest and expensive. A super computer
contains a number of CPU which operate in parallel to make it faster.
It also known as grand father computer.
Application – whether forecasting, weapons research and development.
CLASSIFICATION OF DIGITAL COMPUTERS
Desktop
Workstation
Notebook
Tablet PC
Handheld computer
Smart Phone
WORKSTATION
TABLET PC
HANDHELD PC (PDA)
SMART PHONE