Computer Basics What do you mean by Computer …? It is an electronic device that is able to take raw input or “data” from a user, store it, process it and output information as per requirement. Significance: Computer is Intelligent machine Has left great impact on our day to day life. Responsible for reducing our efforts by automating many tasks and saves our time also. Eg: Online booking tickets (Railway, Plane and Bus), ATM Machine, update our bank passbook.

Evolution Of Computers Two ERA’s Machine Era (Before 1965) Electronic Era (1945 –till Date) Generation of Computers: First Generation ( )  Use of bulky electric tubes  Large Space  Slow Speed Second Generation ( )  Use of Transistors  Reduced Size

Third Generation ( )  Use of IC’s  Low Cost  High Processing Speed Forth Generation ( )  Use of VLSI  Use of Microprocessor Fifth Generation (1990-Till Date)  Characterized by very high speed  Implements parallel processing

Features of Computer  Performs Information processing with amazing speed  Reliability  Accuracy  Ability to store huge amount of data and Information  Ability to communicate with Computers

Operation Performed By Computer Computers perform four general operation: a)Input b)Process c)Output d)Storage

Components of Computer System

Input Devices : Means to collect information from user and insert into the computer. Eg: Keyboard, Mouse, Joystick, Scanner etc. Central Processing Unit : CPU contains electronic circuits that cause processing to occur. CPU interprets Instructions. CPU performs logical and arithmetic operations. CPU is brain of the computer. CPU has two parts: 1)Control Unit: It controls signals between memory and ALU. 1)Arithmetic and Logic Unit: It performs arithmetic and logic operations.

Memory: Memory is also called as Random Access Memory(RAM) i.e Temporary Memory. RAM is main memory of the computer. RAM is electronic component that store data i.e numbers, letters, alphabets, graphics and sound. ROM is memory that is etched on the chip that startup directions for the computer. ROM is the permanent memory. Measurement of the Memory: Measurement of the memory is done in the Kilobytes and Megabytes.

Memory: 1 KB = 1000 memory locations 1 MB = Approx One Million memory locations RAM= Random Access Memory ROM= Read Only Memory PROM= Programmable Read Only Memory EPROM= Erasable Programmable Read Only Memory EEPROM=Electrically Erasable Programmable Read Only Memory

OUTPUT DEVICE : The output device are 1)Printer 2)Computer Screen STORAGE DEVICE : The auxiliary storage device are 1) Floppy Disk 2)Hard Disk 3)CD-ROM’s 4)Pendrive

HARDWARE AND SOFTWARE : ss SOFTWARE HARDWARE USER HARDWARE: Physical components of the Computer SOFTWARE : Instructions that make computer work

What is Open source…? Open source describes a broad general type of software licence that makes source code available to the general public non- existent copyright restrictions. Open source usually available to the user to view, modify and again redistribute under certain licensing term. It offers following freedom to its user:  Free to use  Free to change  Free to distribute  An alternative to commercial software

What is Open Source Software..? It is computer software that is available in the source code form. It can evolve through the community co-operation. The community is an individual or well large company. Few are popular example of open source software:  Eclipse - Development environment comprising an IDE  Mozilla Firefox- Web Browser  Perl- A general purpose programming language  PHP-A scripting language suited for web  Ruby- A general purpose programming language  Python – A general purpose programming language.

What is Open Source Operating Systems o Operating System is the software that you use to operate your PC (like Windows or Linux). o Linux is example of Open Source Operating System o Windows and Macintosh both are closed proprietary system. o “Linux”, is a Unix like OS assembled under the model of free and open source software development and distribution. o The defining component of Linux is “Linux Kernel”, an OS kernel first released on 5 th Oct 1991 by “Linus Torvalds”. o BOSS : Bharat Operating System is also one of the good example of O.S.

Features Linux Windows Distribution Open Source Closed Source Price Free or at a much lower price than Microsoft Windows Microsoft Windows can run between $50.00 or $ US Dollars per each license copy Ease It is bit harder to use new computer users Windows is still much easier to use to new users Reliability The majority of Linux Variants are reliable i.e can run for months and years without reboot It still can not match reliability of Linux Software Linux has a large variety of available software prog It has much large selection of available soft SecurityIt is Secure OS It may fall prey to Virus and other attacks

Bharat Operating System Fig: GUI of Bharat Operating System

Bharat Operating System(BOSS) BOSS is GNU/Linux distribution developed by C-DAC(Centre for development of Advanced Computing) GNU is a computer operating system composed entirely of free software. GNU is developed by the GNU Project and the development of GNU was initiated by Richard Stallman and then publicly announced as GNU operating system on September 27, 1983, which was the original focus of the Free Software Foundation (FSF).

It is developed by “Debian” for enhancing the use of Free/Open Source Software throughout India. This release aims more at the security part and comes with an easy to use application to harden your desktop. BOSS GNU is available in all official Indian Languages such as Assamese, Bengali, Marathi, Gujrati, Telgu, Kashmiri and many more. Debian is one of the flavour of linux. Flavour is nothing but linux technical terminology used to refer the distribution type. Some popular flavours of linux are: Redhat, SUSE, Fedora,Ubuntu,Mandrake

Features of BOSS: 3D Desktop Kennel an Application to send SMS Multimedia Support Hardware Support for digital camera, printers, scanners, bluetooth, WiFi Auto Detection of the devices.

Interaction with Linux Through Commands

Programming Languages Fig : Programming Languages

Programming Language : It is used to communicate Instructions to the machine. The language acceptable to the computer is called as computer language or programming language. The process of writing sentences in such language is called as “Programming or Coding”. Using program we can control activity of the computer. There are different types of languages for the different task. Each is having some ADV & DISADV.

Types of Programming Language : There are two types of Programming Language: 1)Low Level Language 2)High Level Language

Low Level Language : Low Level language is simple but very difficult to use. Low Level Language is the M/C codes. Computer can understand only the program written in the low-level language.  M/C Language and Assembly Language are Low Level Language M/C Language : M/C language instructions use series of the binary digits “0 & 1” It also uses series of numbers and letters but they are also represented in “0’s & 1’s” “It is only language understood by the Computer”. It is M/C Dependent language and it can not run on another M/C

M/C Language Instructions has 2 Parts: 1) Operation Code(OPCODE) 2) Operand Fig : Instruction Format

Advantages of M/C Language: It is only one language which is understood by the “Compiler” It is very simple It makes fast and efficient use of the computer It is directly understood by the computer it does not require any translator to translate the code Limitations of M/C Language: Writing program in the M/C language is difficult and time consuming All operation codes and memory address needs to remember

Limitations of M/C Language, Continue…. It is difficult to find error in the program Difficult to correct and modify the program Programmer should have detailed knowledge about the hardware

Assembly Language : Assembly language program overcome some of the many inconveniences of machine language In assembly language operation codes and operands are given in the form of alphanumeric symbols instead of binary numbers 0 and 1. These alphanumeric symbols are called as mnemonic codes It is also called as “Symbolic Programming Language” Assembly language programs are translated into executable machine code by using “Assembler”.

An Example of a Typical Assembly Language is : MOV AX,47 MOV DS,AX ADD AX,DS

Advantages of Assembly Language: It is easy to understand and Use as compare to M/C language It is easier to modify It is efficient It is easy to find errors and easy to debug Limitations of Assembly Language: Assembly Language is also machine dependent. The programs written for one machine cannot be executed on another Machine Writing Assembly language program is difficult and time-consuming

High Level Language : High level language allows people to write program easily, in their own native language It uses “English Words, Mathematical Symbol”, rather than mnemonic code HLL deals with variables, arrays, objects, arithmetic, or Boolean expressions, subroutines and function, procedures and threads The program written in the High Level Language must be translated into Machine Level Language by Compiler or Interpreter

E.g of High Level Language are C, COBOL, PASCAL, LISP

Interpreter : Interpreter is one of the translator which has important advantages over compilation The DATA & SOURCE PROGRAM are input to the interpreter, instead of producing any object module as in the compilation, the interpreter directly produces result by performing operation of the source program on its data

Scripting Language : This is form of programming language that support writing the script Scripting language are interpreted rather than compiled Program in scripting language is interpreted one command at a time E.g: PHP, Python,Ruby Perl..etc Advantages of Scripting Language: It is easier to write a code in the scripting language Programming knowledge is required Complex task is performed in few steps Editing and running scripting code is fast

Limitations of Scripting Language: Scripting languages are slower and more time is required for the interpretation Scripting language is harder to debug as no development environment is available by default All scripting languages are not supported by all the systems

Natural Language : Natural language is the language which is acquired naturally Natural language arises in the accidental fashion as the result of the inborn facility for language A natural language is typically used for human communication and may be spoken and written No training is required for these languages, this language uses words and symbols, these set of words and symbols is called as “Vocabulary” E.g: English, French, Chinese

Characteristics of Good Programming Language : Some programming languages are popular and some are not popular. The Success of Programming Language is based on following points : Programming language should be Simple and Readable Programming language should be Portable Programming language should be general, i.e it allows writing wide variety of programs thus helping programmer to get expert in many diverse programming Programming Language should be widely available, i.e it should be able to provide translator for entire M/C for all OS

Programming Language should be efficient, i.e program written in the Programming Language should be efficiently translated into machine code Programming language should provide modularity to develop the program Depending upon the type of application for which a programming language has been designed, the language must be suitable to its environment

Selecting a Language out of many Available Language for coding Application : Many languages are available for coding the particular application or subprogram. So how to select the suitable language……? Following are the some points which can be considered while selecting the language to code the application. If application is operating system intensive then choose C/C++ If application is operating system independent then choose JAVA programming If it is open source then PHP is best option

If there are Multiple languages found suitable for the application area, the language selected should be one that is easy to learn and use Depending upon the size of the application programming languages are selected While developing the Web-Page, Java Server Pages(JSP),PHP or HTML scripting languages are preferred If there are Multiple languages found suitable for the application area, the language selected should be one that is best known to the programmers For large organization, the choice of language might involve factors such a how easily the program can be ported to different platform

Subroutine Subroutine is set of instructions that perform a specific task for the main routine and transfer control back to the main routine after execution Subroutine is part of source code within larger program that performs a specific task and is independent of remaining code

#include void main() { message(); printf(“\ nAre from MESCOE”); } message() { printf(“\ENTC And MECH Students”); } O/P: ENTC and MECH Students Are from MESCOE

Examples of High Level Programming Language  FORTRAN: It is oldest programming language developed by the team of programmers at IBM and was published in 1957 FORTRAN stands for FORMULA TRANSLATION as it was designed to allow easy translation of math formulas into the code Ex : PROGRAM HELLO WRITE(UNIT=*,FMT=*) ‘HELLO WORLD’ END

 COBOL: It is earliest high level programming language It stands for Common Buisness-Oriented Language It was developed in 1959 by group of computer professionals called the conference on Data Systems Language Features:  COBOL programming language is self documenting  It has large set of class libraries Applications:  It is suited for solution of business problem  It was first used by department of Defense

 PASCAL: Pascal is procedural programming language Features:  Pascal contain its own built in data types of Integer, Character, Real etc….  Pascal language is simple and expressive in the nature Ex: PROGRAM Hello World; BEGIN WRITELN(‘Hello World’) END. Application: Pascal is used for the learning environment

 SNOBOL: SNOBOL is series of computer programming language stands for String Oriented and Symbolic Language It was invented in 1962 by Bell Labs Ex: OUTPUT= ‘Hello World’ END Applications :  Used for the database program  It is used for the research tool

 LISP: Introduction:  It is a family of Computer Programming Language  LISP means “List Processing Language”  It is based on formal functional calculus History: It was developed by John McCarthy in 1956 List of Interpreter to execute LISP Programs: Emacs Omega Lisp Works

Program to Print Hello World >>(print “Hello World”) OUTPUT: “Hello World”

 OCTAVE(GNU Octave): This is open source free license software This is free Software Advantages: This software works on Windows as well as on Linux This gives 2-D and 3-D Graphics Views All syntax of Matlab works without any change in the software Disadvantages : Lack of proper support Performance of software is not proved till now

Importance Of Documentation What is Documentation…? Keeping any record of an event or activity with its result is documentation Ex. Students Admission a)The students may have done fairly well in the entrance test but without document of the result it is impossible to get admission b) Due to documentation of the previous years cutoff’s you can guess which college to apply for….? c) By taking real life inspiration, in the software industry documentation was introduced

Advantages Of Documentation  Helps to train new users  Helps in detecting mistakes  Guideline in creating new software  Helps in the cost estimation  It is used for the legal procedures  It is used for coordination between the team members who make the software

Five major developments of Software Development 1)Idea or Need: This level is referred as requirement. The basic idea of the software is put. 2)Design: This step will give fair idea of how the software will be….?, also know as modeling. 3)Development: This step converts the model developed in previous level to actual functionality. 4)Testing: This step test the functionalities developed for quality. 5)Delivery: Fully furnished software product is given to users.

Types Of Documentation Requirements Document: Part of the agreement between company selling the software and customer. The document contains all requirements. Cost Estimate Document: This document contains probable cost of people, machinery, electricity, and other expenditures required for making S/W. Architecture Documentation: Here different parts or modules of software and their functions are described. Program Documentation: This documentation related to the code of S/W. Programmer of Coder writes this documentation.

Testing and Quality Documentation: These documents maintain record of quality of the Software. User Manual: This document is used for the user. This is the guide for user to handle the software. Product Brief: This is document for the marketing people. It highlights advantages of software over others License: This is an agreement between user and company. User agrees Terms and Conditions,company gives rights to user to install the copy or distribute. Actual Cost Document: This document gives actual expenditure for the software.