Some Basic Knowlege About Computer
What is a (digital) computer?
A computer is a system of electronic devices that accepts raw data as inputs, processes and manipulates them in digital form to provide outputs (results) and store them for future use.
Inputs from input devices.
Save or hold input data.
CPU (Central Processing Unit) process.
Output from output devices.
Save to memory.
Storing and remembering
A computer can handle a number of tasks in a fraction of the time that would take a human for a longer period of time, even days or a month.
Ability to process very large amounts of data.
Speed in microseconds, nanoseconds and picoseconds.
The computer generated result can have higher accuracy and precision.
Its accuracy can be increased according to requirements.
Provide outputs based on inputs.
It’s hard and works until it stops.
He continues to work according to the program and does not feel tired or lazy.
The same computer can be used for different jobs or jobs.
The same computer for different tasks.
Save and remember:
A computer can store a large amount of data.
Once saved, it can be used anytime as needed and don’t forget the data.
It can store different types of data (image, text, sound, etc.).
Once programmed, it automatically continues to perform the task.
A large amount of data and commands are processed in a computer.
As a request, the data is processed and provides an output.
Every task needs to be processed.
Absence of intellectualism.
He can’t decide what to do.
It continues to work as programmed.
No logical thinking unless programmed.
Education, Library and Design
Industry and manufacturing
Research, exploration and simulation
Hospital and health
Science and Engineering
Management of offices and hotels
Advertising and marketing.
Entertainment and communication.
Airlines and navigation
Advantages of the computer
Computers are much more accurate and reliable than any other devices and human beings.
They are very useful for repetitive jobs that are difficult and tiring for humans.
Computers are much faster than humans.
With the help of a computer, complex things can be easily simulated and demonstrated.
It is versatile and can do different types of work.
It can be used in multiple areas, so it is called a universal machine.
Due to the availability of storage, data can be saved for future use and programs can be modified to add functions for different purposes.
No repetitive work, so you save time, labor and physical waste (design) of material.
Communication technology has advanced a lot with the use of computers.
Disadvantages of computer:
It is expensive and beyond the reach of poor people. This limitation is overcome as its cost is decreasing drastically day by day.
It is an electronic machine, so there is a great risk of electric shock and other physical damage.
As people rely more and more on the computer, sometimes the failure of equipment and programs can produce unreliable information and cause data loss to a large extent.
Increases dependence on the machine. Even for every simple calculation, people need them.
While this helps in faster and cheaper communication, there is a great risk of security breach.
It increases the piracy of intellectual property (films, publications, etc.) in large volume.
Since computers are used in sensitive areas like national defense, civil aviation, banking, even a simple glitch can cause loss of life and property.
A generation of computers
First generation (vacuum tube based).
Second generation (transistor based.)
Third generation (IC based.)
Fourth generation (Based on VLSI microprocessor.)
Fifth Generation (Biochips and Artificial Intelligence)
The period of the first generation was 1942-1954.
Vacuum tubes (Valves) as basic components for memory and circuits for CPU.
Very large size occupying the entire room.
It consumes a lot of energy (electricity) and produces a lot of heat.
Punched cards and paper tapes were used as input, and outputs were limited to printouts.
Using a machine-level language.
Storage capacity was limited to 1KB-4KB.
Low operating speed and the slowest of all other generation computers.
Fig.: First generation computer
Example: UNIVAC and ENIAC.
The period of the second generation was 1952-1964.
Transistors were used instead of tubes.
Smaller size compared to first generation computers.
It consumes less power and generates less heat compared to first-generation computers.
Faster and more reliable than first generation computers.
Symbolic instruction and high-level programming language like FORTAN, COBOL were used.
Using magnetic core technology instead of magnetic drum.
Magnetic core memories for internal storage and magnetic disk and tapes for auxiliary memory.
Fig.: Second generation computer
Example: ATLAS, Mark III, IBM 7000
Note: A transistor is a small electronic device made of semiconductor material such as germanium and silicon. Compared to vacuum tubes, it is much smaller and consumes less power. In 1947 Bell Laboratory introduced the first transistor and in 1958 it was used in a computer.
The period of the third generation was 1964-1972.
Instead of transistors, integrated circuits (ICs) were used.
Smaller size than the second generation because many transistors can be integrated into an integrated circuit.
Low power consumption than the previous generation.
High-level languages like FORTAN-II, ALGOL-68 were used.
More reliable and efficient than previous generation computers.
Keyboard and monitor as input and output devices.
A real-time operating system and a multi-programming operating system were used.
Fig.: Third generation computer
Example: IBM-360 series, IBM-370/168
The period of the fourth generation was from 1972 to the present.
Use of Very Large Scale Integration (VLSI) technology and microprocessor.
As thousands of transistors and other circuits were integrated into a single chip, the size of the computer was drastically reduced.
Cheaper in price and lower consumption.
During this time, there was a great deal of success in computer technology, including hardware and software.
Still using a computer from this generation.
Highly accurate, reliable and operational speed.
Massive use of magnetic and optical storage devices.
Multiprocessing, multiprogramming, multimedia and distributed computing are possible.
The concept of the Internet was introduced.
An introduction to PCs for ordinary people.
Fig.: Fourth generation computer
Example: IBM PC, Pentium PC
The era of the fifth generation is present – the future.
Based on artificial intelligence and still under development.
Some applications such as voice recognition and