What is A Computer?

A computer is an automatic electronic device that performs both mathematical and logical functions expressed in numerical or logical terms.

It is a high speed data manipulation electronic system that records, manipulates and retrieves data.

 

What is IPOS Cycle?

            For performing any given task, a computer uses the following operation:

  1. Input – Raw data is entered into the computer with the help of any input device.
  2. Processing – Operations are performed on the data inputted.
  3. Output – The result of the processed data is displayed as output on the output devices.
  4. Storage – These results are stored for future use.

 What are the various characteristics of computer?

  1. Accurate & Reliable
  2. Diligent
  3. Versatile
  4. Storage & retrieval of data
  5. High Speed

 

What are the units to measure the speed of data processing by a computer?

            The speed for data process is measured in milliseconds, microseconds, nanoseconds and picoseconds.

            1 Millisecond = 10-3 seconds

            1 Microsecond = 10-6 seconds

            1 Nanosecond = 10-9 seconds

            1 Pico second = 10-12 seconds

 

What is the main purpose of a computer?

            The main purpose of a computer is to transform data into information.

Data are the basic facts which are generally unorganized where as the meaningful context of data is called Information.

In other words Data are raw facts and Information are processed data.

What are the five elements of Data Processing System?

            The five elements of a computer data processing system are –

  1. Hardware – The physical parts of computer. The computer itself (i.e. CPU, Memory) and p[peripheral devices (input devices, output devices, secondary storage devices)
  2. Memory – Memory and storage aren’t same. Memory is temporary which gats lost when the computer is switched off whereas storage is permanent and has greater capacity than memory. A computer stores data digitally, using binary digits. A binary digit known as a bit has a value of either 1 or 0. Eight bits  Bits together make a character which is also called a byte.

 

8 Bits =   1 Byte

1 Kilobyte = 1024 Byte

1Megabyte = 1024 Kilobyte = 1024 x 1024 Byte

1 Gigabyte = 1024 Megabyte = 1024 x 1024 x 1024 Byte

     

  1. Software – It is a set of instructions that guides a computer to do a specific job. Soft wares are classified into System Software and Application Software. System Soft wares integrate the computer’s hardware components and provide tools for day to day maintenance tasks. It also provides the user a platform to perform their task on the computer. (Operating Systems like Windows, Unix, O2,etc. are examples of system software).

Application Software helps the computers to perform specific tasks. (Tally, MS – Excel, WordPad etc. are examples of application software)

Some application software are Special Purpose Programs which perform a single task for a single profession. The application software that are used by millions of users for variety of task are called General Purpose Programs.

  1. Data – The raw facts that are input in a computer are called data. We know that computers transform data into information. This transformation of data into information is represented by a model called System Model.
  2. Procedures – Procedures are the steps that are to be followed to accomplish a computer related task.

 

Give details about the various generations of computers.

            The following are the details about the various generations of computer –

Generation Years Circuitry Characterized By

First

1951 – 1959

Vacuum Tubes

Magnetic drum and magnetic tape; difficult to program; used machine level and assembly level language

Second

1959 – 1963

Transistors

Magnetic cores and magnetic disk, used high level languages and were easier to program.                                                                                                      

Third

1963-1975

Integrated Circuits

Minicomputer accessible by multiple users from remote terminals

Fourth

1975 – present

VLSI

The Personal computer and user friendly micro programs; very fast processor chip, high level language; object oriented programming (OOP).

 

What are the various classifications of computers?

            By Functions – a) Digital Computers

                                       b) Analog Computers

                                       c) Hybrid Computers

            By Size – a) Super Computers (Multiprocessing)

                             b) Mainframe Computers (Multiprogramming)

                             c) Minicomputers (functions like mainframe but at a smaller scale)

                             d) Workstations (RISC based microprocessors)

                             e) Microcomputers (Multitasking)