Basic Computer Fundamental Course Material By Mangal Sir

Basic Computer Fundamental Course Material

Friend's today we are talking about most important topic Computer Fundamental Course Material for Computer Exam and Competitive exams. We are providing you with a Computer Course Material based on the types and patterns of questions asked in the Computer Awareness are always important for NIELIT Exam, Govt Departmental Exam, IBPS PO, IBPS Clerk and Others Exam.

Basic Computer Fundamental Course Material Provided by: Mangal Sir

Computer is an electronic device which is used to accept data, process them and finally gives us an output result as per our instructions. OR

Computer is the combination of hardware and software.

Hardware: - All the physical parts of a computer system are called Hardware.

There are three types of Hardware:

a. Input Hardware (Keyboard, Mouse, Scanner, Mick, OMR, OCR, MICR)
b. Processing Hardware (CPU)
c. Output Hardware (VDU, Printer, Speaker, Plotter)

Program: - The sequential set of instructions given to a computer system is called program.

Software: - The series of programs or instructions written for computer system is called software.

There are 2 types of Software:

a. System Software: Those software which are designed only for a computer system are called System Software.

E.g. OS (Windows, UNIX, and Linux), Interpreter, Compiler, Assembler.

b. Application Software: Those software which are designed for a specific task are called Application Software.

E.g. MS-Office, Tally, SCORE (Registration dept.)

Features of Computer:

  • High Speed
  • Accuracy
  • Diligence
  • Versatility
  • Disadvantages: It cannot take self-decision.

Similarities between Human Body and Computers:
  • Both work on IPO method (Input-Output processing)
  • Both are combinations of hardware and software.

Types of Computers:

  • On the basis of Uses, there are 3 types of computers: Analog, Digital and Hybrid computers
1. Analog Computer: - In analog computers data are represented as physical quantities. Physical quantities are best measured in a continuous fashion and thus are ideally suited for analog computation. Analog computer is a machine that works on data which is always changeable. Speedometer, Analog watch, Thermometer, Voltmeter etc. are example of Analog computer.

2. Digital Computer: - In digital computers data are represented as discrete unit or electrical pulse, which can be counted and switched. In modern digital computer binary system is used. Digital clock is the example of Digital computer.

3. Hybrid Computer: - Hybrid computers have combined features of both digital and analog computers with the input and output in analog form and the processing in digital form. This involves analog to digital converter at the input end and digital to analog converter at the output end. Example- Robot

  • On the basis of purpose which they design: There are 2 types: -

1. General-purpose Computers: - The general purpose computer are flexible and versatile. They can be used to solve a variety of problems by changing the program or instruction. 
Example- Accounting, Simulation and forecasting.

2. Special purpose Computers: - The special purpose computers are used to solve a single and dedicated type of problem. For their specialized use, they are extremely efficient and economical. 
Example- Automatic aircraft landing, computerized traffic control system.

On the basis of size and data storage capacity, Digital computers are classified in 4 categories.

1) Micro-Computer: Microcomputers are based on microprocessor. Microprocessor is an integrated circuit. It also known as PC. Single user computer. Microcomputers are the least powerful, yet the most widely used and fastest growing type of computer. The processing speed of a microcomputer is 1 lac instruction per second.
Example: - APPLE MAC, I Mac, IBM PS/2, IBM compatible and PS 386, 486 etc.
Uses: - Home, office, business, School etc.

There are three types of microcomputer.
(i) Desktop Computer
(ii) Laptop Computer And
(iii) Palmtop Computer

2) Mini-Computer: 5-50 times faster than microcomputers. It is a multi-user computer. Bigger than micro, speed and price higher than micro. The processing speed of a minicomputer is 5-50 lac instruction per second. It is used as a server for small organizations.
Example: - IBM- 17, DEC PDP11, HP- 9000, AS 400, BULL HN- DPX2 etc.

3) Mainframe Computer: Mainframe computers are characterized by large internal memory storage and comprehensive range of software and peripheral equipment that might be connected. It occupied specially wired, air-condition room. It is multi-user computer. It is used as a server for larger organizations—Banking system, Railways reservation, Aircrafts, ATMs, Telephone exchange.etc.
Example: - IBM- 370, IBM- S/390, DEC VAX- 8800, UNIVAC- 1110

4) Super Computer: supercomputers are the most powerful computers as now. These computers are large in size and memory compared to all other computer. They work with multi-processing and parallel processing facilities. At present, specially in computing speed, these are very fast. So, these are the fastest, biggest and most expansive computer. It is an advanced version of Mainframe computer. Weather forecasting and reports, scientific research and experiments, defense related experiments, interlinking of ATMs of different banks, creation of 3D movies. It can perform 25 thousand million arithmetic calculations per second.
Example: - CRAY- 1, IBM’s Deep Blue, PARAM etc.

*First supercomputer of world was CRAY – 1 which was developed by Cray Research Company in 1976.

*First supercomputer of India was PARAM which was developed by C- DAC in 1991.

C- DAC – (Center for Development of Advanced Computing)

Operating System

The operating system works as a mediator between hardware, application system and user. Operating system are programs that coordinate computer resources, provide an interface user and computer and run application programs. They manage the computer’s processes functioning as an interface, connecting users with the application software and the hardware. Every general – purpose computer must have an operating system to run other programs. It control different components of a computer and allows users to interact with computer.

Types of operating system:

1. Real time operating system: - A real time system is a computer system capable of processing data so quickly that the result are instantly available. There is often a need for front end processor in the system. A real time operating system is an operating system that guarantees a certain capability within a specified time constraint. If the calculation could not be performed for making the object available at the designated time, the operating system would terminate with a failure. A real time operating system typically has very little user-interface capability, and no end-user utilities, since the system will be a “sealed box” when delivered for use.

2. Multi-access operating system: - It allows two or more users to run programs at the computer’s resources simultaneously. Some operating system permits hundreds or even thousands of concurrent users. The operating system must make sure that the requirement of the various user are balanced, and that each program they are using has sufficient and separate resources so that a problem with one user doesn’t affect the entire community of users. Unix, Linux and Window 2000 are examples of multi-access operating system.

3. Multiprocessing operating system: - It is an operating system when two or more processors are present in a computer system sharing some or all of memory. It supports running a program on more than one CPU. Unix, Linux and Window 2000 are examples.

4. Multitasking operating system: - It allows more than one program to run concurrently. An operating system that is capable of allowing multiple software processes to run at the same time. Unix and window 2000 is an example.

5. Time sharing operating system: - Processor time is divided into small units called time-slices and is shared in turn between users to provide multi access.

6. Multi-programming operating system: - More than one program resides in main storage and is being processed apparently at the same time. This is accomplished by taking turns at short bursts of processing time.

7. Batch processing operating system: - The job is not processed till there is full input. The jobs are entered and stored on a disk in a batch queue and then run together under the control of the operating system. A job may wait in a batch queue for minutes or hours depending on the work load.

8. Single rasking operating system:single user, single task: - As the name implies, this operating system is designed to manage the computer so that on user can effectively do one thing at a time. The palm operating system for palmtop computers is a good example of a modern single-user, single task operating system.

9. Single-user multi-tasking operating system: - This is the type of operating system most people use on their desktop and laptop computers today. Microsoft’s Windows and Apple’s Mac operating system are both example of operating system that will let a single user have several programs in operation at the same time. For example, it’s entirely possible for a windows user to be writing a note in word processor whole downloading a file from the Internet while printing the text of an e-mail message.

Memory: Memory is part of computer where data and information are stored.

There are 2 types of Memory: Primary (Temporary) and Secondary (Permanent)

RAM: (Random Access Memory): - It is a volatile memory. It is the most common type of memory used in computer. It works with the CPU to hold instructions and data in order to be processed. It is the first place where data and instruction are placed after being input, and processed information is placed in it to be returned to an output device. But it can hold data only temporarily because it requires a continuous flow of electrical current. If current is interrupted, data is lost. It allows data to be read and written randomly not in sequence, so read and write of data is bit quickly.

There are two types of RAM: Dynamic RAM and Static RAM

(a) Dynamic RAM: - It requires constant refreshing of its contents. It loses its content in a very short period even though computer is working.
(b) Static RAM: - It does not require refreshing. It retains its content till computer is working.

Cache Memory: - A cache memory is a temporary storage area where frequently accessed data can be stored for rapid access. Once the data is store in the cache, it can be used in the future by accessing the cached copy rather than recomputing the original data. The CPU and hard drive frequently use a cache. When the processor needs to read from or write to a location in main memory, it first checks whether a copy of that data is in the cache. If so, the processor immediately reads from or writes to the cache, which is much faster than reading from or writing to main memory.

ROM (Read Only Memory): - It is a non volatile memory. Data and instructions stored in it which can be read, only modified or destroyed. It is commonly used for storing program instructions that are not required to change. It is an internal storage area in the computer. It is silicon chip on motherboard on which instructions are burned at the time of manufacture. When switched on, the computer instructions stored there is automatically initiated and after switching off instructions do not get lost. These permanent instruction stored in ROM are called BIOS (Basic Input Output System). On computer the BIOS contains all the instruction required to control the keyboard, display screen, disk drives, serial communication and number of miscellaneous functions. The BIOS is copied from ROM to RAM each time the computer is booted. This is known as shadowing.
  • Primary Memory: ROM (Read Only Memory), RAM.
  • Secondary (permanent): Hard Disk, Floppy, CD, DVD, pen-drive, Cache.
  • Binary digits are called bit.
  • The smallest unit of measurement for memory is known as bit.
  • Byte: It is a collection of eight bits.
Note: One character takes eight bits (one byte) space in Memory, be it in capital or small.

Generation of Computers: 

1st Generation Computer (1946-1954): The first-Generation computers usually used vacuum tubes as CPU components. Around 18000 vacuum tubes were inserted in it. Magnetic tape and Magnetic drums were used for secondary memory. Programming language was low-level programming (machinery/ assembly language). E.g. IBM 700 series- IBM 701, IBM 704, IBM 709, EDVAC (Electronic Discrete Variable Automatic Computer), UNIVAC (Universal Automatic Computer) etc.

2nd Generation Computer (1955-1964): The second-Generation computers used transistors for CPU components and ferrite cores for main memory, and magnetic disks and tapes for secondary memory. They used high level language such as FORTRAN, ALGOL, and COBOL for programming. Example of second generation computers IBM 1620, IBM 7090, IBM 7094 (I), IBM 7094(II), CDC 1604, PDP 1 PDP 5 PDP 8 etc.

ALGOL (Algorithmic and Logical)
COBOL (Common Business Oriented Language)
FORTAN (Formula Translation)
IBM (International Business Machine)
CDC (Control Data Corporation’s)
PDP (Programmed Data Processor)

3rd Generation Computer (1965-1974): The third generation computers used ICs (Integrated Circuits) for CPU Components. In the begging of third generation computer uses magnetic cores memory, but later on Semiconductor memories (RAM and ROM) were used for Main memory. Magnetic tape and magnetic disk were used as secondary memory. Cache memory also incorporated in the computer. Microprogramming, parallel processing, multiprocessing, multiprogramming, multiuser system etc. were introduced. The concept of virtual memory was also introduced. The example of third generation computers are: IBM/ 370 Series, CDC 7600, PDP 11, CDCs CYBER- 175 and STAR- 100, etc.

4th Generation Computer (1975- at present): The fourth generation computers use VLSI chips for CPU, memory and supporting chips. They used microprocessor as CPU. 32-bit and 64-bit microprocessors are available today. A powerful computer contains more than one 32-bit or 64-bit RISC (Reduced Instruction Set Computer) microprocessor. The latest microprocessors contain 3-20 million transistors.

BASIC, C, C++, JAVA, PROLOG etc. programming are used. 4GLs like ORACLE, SYBASE, etc. are used for database management.

5th Generation Computers are under development. Japan and USA are developing the 5th Generation computers. CPU components will be ULSI (Ultra Large Scale Integration) chips will be used. It can take self decisions.

Desktop— Main Screen (Over all area of the first screen is called Desktop)
Task Bar: The long horizontal bar, bellow the desktop is called taskbar. It includes start button, open files or folder name, some icon and time indicator.
ICON: Any pictorial or symbolic representation is called Icon.

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