Computer fundamentals -types, os, languages etc.pptx

Fundamental concepts

1. Computer fundamentals Chapter-1 By, ASHWINI K S

2. Types of computer Computers are of different sizes. On the basis if the size of the computer, we can classify computers as, mobile computers Micro-computers Mini-computers Mainframe computers Supercomputers

3. Mobile computers These are the smallest computers. They are designed to be carried around by the user. Some of the mobile computers are, Pocket PC Personal digital assistant-PDA Portable media player-PMP Tablet PC Smartphone Laptop

4. Microcomputers A computer that uses a micro processor is called Micro computer. They are larger and occupy more space in comparison to mobile computers. They are usually placed on a desk (table), so that it is easy for the user to use the computer. They are also called as Desktop computers .

5. minicomputers A minicomputer is powerful than micro computer. These computers were manufactured in 1960s. But they are replaced by micro computers in 19190s. Still there are few mini computers in use. They use the advanced version pf micro processing. They are referred to as servers . CDC 160 A, DEC PDP and CDS-92 are some examples of minicomputers.

6. Mainframes Mainframes are large and powerful computers. They used in large organizations like bank, insurance companies, government offices for data processing work. Mainframes support thousands of users at a time. They handle large data with simple calculations. Example of main frames are IBM systems and Non stop. These computers are meant for business and government applications

7. Supercomputers Super computers are the largest, fastest, most powerful and the most expensive computers. Like main frames, supercomputers can be accessed by many individuals at the same time. These are very fast computers that can handle a very large data. They have the capacity of processing trillions of instructions per second. These computers are used for scientific and military data handling. The first super computer was introduced in 1960, by Seymour Cray. ‘The earth simulator’ at ‘Yokohama Institute for Earth S cience, Japan’ is the fastest super computer. PRAM series supercomputers have been developed by the C entre for D evelopment of A dvance C omputing (C-DAC) in Pune, India. ‘Padma’ is the latest supercomputer in this series. PRAM 10000 is mainly used for long range weather forecasting, remote sensing and molecular modelling.

8. Software and types of software Software means set of computers programs. Program is a set of instructions. Software's are necessary to run any computer. Without software the computer doesn’t work. Software’s can be classified as below System software Application software

9. Classification of software

10. System software System software is a collection of programs. These software's help the computer to function. it helps the computer to perform tasks such as controlling all the operations, moving data in and out of a computer and running application programs. System software can be classified as following.

11. Operating system An operating system is the master control program that runs the computer. It is the first program that is loaded into the computer. It is the main component of the computer. The application programs run on the standards set by OS. All the programs will communicate with the operating system. The OS controls the execution of programs The OS ensures that all parts are working properly. Example: Windows, Linux, and MS-DOS

12. Compilers A compiler is a program that takes program written high level language and translates it into machine language. High level language program is called Source code/source program . The action of translating the high-level programming language code is called  compiling . The computer takes the program written by user and first cheeks for mistakes. If there are mistakes , it will show them and then user has to correct all the mistakes. In computer language mistakes are called errors. If there are no mistakes/errors then it converts it into computer machine language in one attempt . The converted program is called object code. The object code is saved for future use. So if the program needed to be executed again , then it can directly executed by using the saved object code.

13. Interpreters Interpreter is also a program which converts source program into machine code/object code. Interpreter method of conversion is different from compiler. It analyses the source program line by line . Here the a line of program is analysed, object code is created and executed. The object code is not stored in this method. So it the program has to be executed again , once again all process should done from the scratch.

14. Application software Set of computer programs designed to help the user in performing a specific type of work. One application software is designed for only one specific purpose. For example student result calculation software cannot be used for student fees calculation. Application software can be classified into two ways.

15. Packages A package is a computer application consisting of one or more programs created to perform a particular type of type.

16. Utilities A utility is a program designed to perform maintenance work on the system, or on the system components. Utility packages include the following: Backup Antivirus Disk Defragmenter

17. Computer languages and their types To explain the computer about how to perform a task, the computer programmer writes a set of instructions and it is called a program. Hence “ A set of instructions written to perform a particular task is called a program” A set of programs written to instruct a computer is called the software. These programs are written in any computer language. Each computer has its own grammar rules which must be known to its user . Similarly there are some symbols to be used and there are rules about how to and when to use it. They are Syntax rules

18. Classification of computer languages Computer languages can be classified as follows

19. Machine language The instruction written in this language is in the form of 0’s and 1’s. This language is called binary language. It very difficult to write program using this language but it is easy for the machine to understand the instructions. Machine language program is machine dependent. Program written for one computer may not work for another. In this programmer has to remember a lot of codes. If any mistake takes place , it very difficult to rectify.

20. Assembly language The assembly language of a computer is a low-level language. This language is developed in 1950 Using English letters. Instructions are given using abbreviations and codes called symbolic instruction codes or mnemonics It is machine dependent. Every machine has its unique set of instructions so needs different program

21. Assembler Assembler is program which converts the program written in assembly language to machine language. Assembly language is language in which program are written using predefined codes. Example: ADD, MUL, SUB etc., The translation process is known as assembly. The program that translated is said to have assembled. Entire program must be assembled before it is executed.

22. High level language HLL emerged in mid 1950’s. They are widely used. They are easier for the programmer to use than low-level languages. It is because they are close to natural language English. High level languages are machine independent. Programs written HLL are also called as source programs. Example: BASIC, C , JAVA

23. Quick review Types of computer Mobile computer Micro computer Mini computer Mainframe computer Super computer Software and its types System software Application software Computer language and their types. Low-level languages High level languages