# Basic operations of a computer

This articles gives you a detailed information about the basic operations of a computer and functions of computer in question and answer format , this article will be very useful for Engineering students and beginners.

The status of this resource is Pending and require some modification by the author.

1. Define computers. What are the basic operations of Computer?
• Computer is a fast operating electronic device, which automatically accepts data from user as input, processes the data by performing calculations and operations on it and produces desired output results. It controls all operations inside a computer.

• Basic operations of Computer are,
1) It accepts data or instructions by way of input.
2) It stores data.
3) It can process data as required by the user.
4) It gives results in the form of output.

2. How will you classify computer systems?
• Based on physical size, performance and application areas.
• we can generally divide computers into four major categories: Micro computer, Mini Computer, Mainframe computer and Super Computer.

3. What are the characteristics of computers?
• Speed
• Accuracy
• Automation
• Endurance
• Versatility
• Storage
• Cost Reduction

4. Specify the Electronic components used for different computer generations.
• I Generation -Vacuum tubes
• II Generation –Transistors
• III Generation- Integrated Circuits
• IV Generation- Microprocessors
• V Generation -Artificial Intelligence.

5. (i)Convert the (756)10 to Octal and Hexa decimal. (JAN 2013)
Octal – 111101110
Hexdecimal: - 1EE

(ii)Write the binary and octal equivalent of hexadecimal number 7BD?
Binary Equivalent of 7BD = (0111 1011 1101)2
Octal Equivalent of 7BD = (011 110 111 101) = (3675)8

6. (i) Find the octal equivalent of the number. (10111001100.1101011)2
(ii) Convert the binary number 110 100 111 101 to octal. (MAY 2014)
(110 | 100 | 111 | 101)2 = (6475)8

7. Enlist the advantage of algorithm. (JAN 2012,NOV/DEC 2014,NOV/DEC 2015)
• The term algorithm is now applied to many kinds of problem solving that employ a mechanical sequence of steps, as in setting up a computer program. The sequence may be displayed in the form of a flowchart in order to make it easier to follow.

8. What are the functions in the input unit and output unit?
• An input unit is a device that is used to input data or information into a computer. Some examples of input devices include:

• Keyboards, Computer mice, Light Pen, Digitizer, Touchpad, Trackball, Image scanner, Webcam, Video capture / tuner cards, Microphones, MIDI instruments.

• Output unit delivers information from the computer to an external device or from internal storage to external storage. Eg: Speakers, Printer, Headphone, Monitor (or) Visual Display Unit (VDU),Plotter.

9. What is pseudo code? Write two characteristics of pseudocode.
• Pseudocode (false-code) consists of short, readable and formally styled English language used for explaining an algorithm. It does not include variable declarations and subroutines. Pseudo code is programming analysis tool that is used for planning program logic.
• Example
Pseudocode for multiplying 2 numbers:
READ values of A and B
COMPUTE C by multiply A with B
PRINT the result C
STOP

Characteristics of pseudocode.
• Since it is independent of any programming language, it can be used by most programmers.
• It is easy to develop a program from pseudo code than with a flowchart.
• There are no accepted standards for writing pseudo codes.

10. Define Flowchart. Why is flow chart required ?
• A Flowchart is a pictorial representation of the logic for solving a task.
• It is drawn using boxes of different shapes with lines connecting them to show the flow of control
• It a program planning tool and helps to understand program logic in a visual form.

11. What is an algorithm?
• Algorithm is an ordered sequence of finite, well defined, unambiguous instruction for completing a task.
• It's an English like representation of the logic and step by step procedure for solving a problem.
• Example: Algorithm to add 2 numbers
Step 1: Start
Step 2: Read 2 numbers A and B
Step 3: Add A and B and store the result in SUM
Step 4: Print the SUM
Step 5: Stop

12. What is a volatile and non-volatile memory?
• Volatile memory: It stores data temporarily in computer memory, it maintains the stored information, only when the power is ON. It is also known as temporary memory/volatile storage.
• Example: RAM
• Non-volatile memory: Non-volatile memory/non-volatile storage is a computer memory that can retain the stored information permanently even when not powered.
• Example: hard / floppy disks & magnetic tape

13. Define Software and Hardware.
• Software is a set of computer instructions that tells the computer about the tasks to be performed and how these tasks are to be performed. Eg: Microsoft word

• Computer hardware is the mechanical, magnetic, electronic, and electrical components making up a computer system hardware.
• Hardware includes not only the computer proper but also the cables, connectors, power supply units, and peripheral devices such as the keyboard, mouse, audio speakers, and printers.

14. What is primary memory and secondary memory?
Primary Memory:
• The primary memory or the main memory is part of the main computer system. The processor or the CPU directly stores and retrieves information from it. This memory is accessed by CPU, in random fashion. That means any location of this memory can be accessed by the CPU to either read information from it, or to store information in it.
• Types of Primary Memory
· RAM-Random Access Memory

Secondary Memory
• The secondary memory is a non-volatile memory that stores the data permanently unless it is erased. It is much slower and also less costly. Examples: Floppy disk storage media, Hard disk, CD / DVD, Pen drive

15. What is RAM and ROM?/Distinguish between RAM and ROM

Random Access Memory(RAM) Read Only Memory(ROM)
RAM is a volatile memory ROM is a non-volatile memory
RAM memory is only used to store the temporary information and is deleted as system shuts down ROM memory is used to store permanent information and cannot be deleted.
RAM stores data and instructions during the execution of programs ROM stores mostly operating system programs
It allows reading and writing od data. It allows only writing of data.
The two main types of RAM are static RAM and dynamic RAM. The types of ROM include PROM, EPROM and EEPROM.

16. Write short notes on cache memory.
? Very high speed memory used to increase the processing speed
? Placed between Main memory and CPU or may be built within CPU
? They store more frequently used data
? They are small in size and expensive
? There can be levels of caches like Level1(L1) cache, Level2(L2) cache, Level3(L3) cache

17. What are registers?
• A special, high-speed storage area within the CPU. It's often referred to as CPU's working memory.
• Registers store data, instructions, addresses and intermediate results of processing
• It is costly and has the least storage capacity.
• All data must be represented in a register before it can be processed.
• For example if two numbers are to be multiplied, both numbers must be in registers, and the result is also placed in a register.

18. Define Nibble, Bit, Byte?
Nibble:
• In computers and digital technology, a nibble is four binary digits or half of an eight-bit byte. A nibble can be conveniently represented by one hexadecimal digit.

Bit:
• A bit (short for binary digit) is the smallest unit of data in a computer. A bit has a Single binary value, either 0 or 1. Although computers usually provide instructions that can test and manipulate bits, they generally are designed to store data and execute instructions in
bit multiples called bytes.

Byte:
• In most computer systems, a byte is a unit of data that is eight binary digits long. A byte is the unit most computers use to represent a character such as a letter, number, or typographic symbol (for example, "g", "5", or "?"). A byte can also hold a string of bits that need to be used in some larger unit for application purposes.

19. What is sequence logic, selection logic and Iteration logic?
• Sequence logic is used for performing instructions one after another in a sequence.
• Selection logic is used for selecting the process path out of two or more alternative paths in the program logic. It uses three control structures called if-then, if-then-else and switches case.
• Iteration logic is used for producing loops in program logic when one or more instructions may be executed several times depending on some condition. It uses two control structures while and do-while.

20. What is Data and Information?
• Data - Data is the fact or raw material for the information processing.
• Information – The processed data is called information.

21. What are the components of the computer systems?
• Basic components of the computer system are Input Unit, Central Processing Unit, Secondary Storage Unit and Output Unit.

22. List some important hardware and software technologies of fifth generation computers.

• In the fifth generation, the VLSI technology became ULSI (Ultra Large Scale Integration) technology, resulting in the production of microprocessor chips having ten million electronic components. This generation is based on parallel processing hardware and AI (Artificial Intelligence) software.
• AI is an emerging branch in computer science which interprets means and methods of making computers think like human beings. AI includes Robotics, Neural Networks, etc. All the higher level languages like C and C++, Java, .Net, etc., are used in this generation.

23.What is pseudo code?
Pseudo? means imitation of false and ?code? refers to the instruction written in the programming
language. Pseudo code is programming analysis tool that is used for planning program logic.

24. Specify the Electronic components used for different computer generations.
I Generation Vacuum tubes,
II Generation Transistors,
III Generation Integrated Circuits,
IV Generation Microprocessors,
V Generation Artificial Intelligence.
25. How will you classify computer systems?
Based on physical size, performance and application areas, we can generally divide computers into four major categories:
Micro computer, Mini Computer, Mainframe computer and Super Computer.
26. What are the components of the computer systems?
Basic components of the computer system are Input Unit, Central Processing Unit,
Secondary Storage Unit and Output Unit.
27. List out the types of computers based on size, memory capacity.
1. Micro computers
2. Mini computers
3. Mainframe computers
4. Super computers

28.What is Super computer?
The fastest type of computer. Supercomputers are very expensive and are employed for specialized applications that require immense amounts of mathematical calculations. For example,weather forecasting requires a supercomputer. Other uses of supercomputers include animated graphics, fluid dynamic calculations, nuclear energy research, and petroleum exploration.

29. What are the rules for writing pseudo code?
Write on statement per line.
Capitalize initial keywords.
Indent to show hierarchy.
End multi line structure.
Keep statements language independent.