Computer Input/Output
Input/Output
⇒ There has to be a physical channel that permits users to supply informations to the computer.
⇒ Devices that permit users to supply information to the computer are called ‘input’ devices.
⇒ Input unit enables us to enter (or ‘Input’) data into a computer. The common input devices are keyboard and mouse.
⇒ Similarly, a physical channel that permits a computer to convey the processed information to the outside world. Devices that permit such a function are called ‘output’ devices.
⇒ Output unit enables the computer to show us the result and the information that we want. The common output devices are monitor, printer and speakers.
⇒ Input and output devices are indispensable, but are not a part of the CPU. They are also called peripheral devices, suggesting that they lie on the periphery of the CPU.
⇒ These devices are also called an interface, because they translate informations for man and machine.
⇒ The most popular input device used in contemporary computers is the keyboard.
⇒ Another way to input information into a computer is to use an Optical Mark Reader (OMR). Optical Mark Readers are capable of reading specially prepared forms. These forms have a provision for black marks to be made using a pen or a pencil in a specific position.
⇒ Most competitive examinations that deal with a large number of students usually use this system.
⇒ Banks use another input device called a Magnetic Ink Character Reader (MICR).
⇒ Special numbers are written on bank cheques using magnetic ink and in a particular style to write different numbers. The MICR passes over the words or characters, examines the shape of the magnetic field created by the character, and is thus able to recognize it.
⇒ Barcodes are oftenimprinted on products inmerchandise stores. A bar code consists of several parallel vertical lines of different thickness that represent the binary digits.
⇒ The bits form a code that can be used to identify the object on which the bar code is imprinted. A bar code reader is used to read the bar codes by detecting the bars by using light.
⇒ The bar code can represent information like the price of the product or its date of expiry etc.
⇒ Menu-driven programs, where the user sees the host of on-screen choices, sometimes use another input devices called the mouse.
⇒ The mouse is a pointing device. It can be gripped in the palm of the hand and moved over a horizontal surface. The motion of the mouse can be monitored by the computer in different ways.
⇒ The movement is measured and transmitted to the computer. This generates a corresponding movement of an on-screen marker called a cursor from one option to another.
⇒ To select an option, the user presses one of the mouse’s buttons.
⇒ Another, input device is a digital camera. A digital camera has a circuit that is sensitive to light.
⇒ The two most common devices are the Visual Display Unit (VDU) and the printer.
⇒ A Visual Display Unit (VDU) uses a cathode ray tube to display informations.
⇒ To represent any character, VDU illuminates a particular pattern of these dots. These dots are also known as pixels, a short form for picture-elements.
⇒ Printers print characters on paper or other similar medium.
⇒ Printers come in three popular versions : dot matrix printers, ink-jet printers and laser printers.
⇒ Dot matrix printers print characters in the form of combinations of very tiny dots. The printing head aligns its ‘pins’ to match a particular pattern of dots.
⇒ Ink-jet printers spray jets of ink on to the paper to print any character. The characters are absolutely smooth as ink is sprayed in a continuous flow.
⇒ Laser printer, uses a laser beam to actually ‘burn’ the characters on to the paper.
⇒ We need to issue the computer a detailed sequence of instructions that it needs to follow to operate upon any data. Such a sequence is called a program.
⇒ A program may directly be written to the RAM or may be stored in some form of secondary memory.
⇒ It may be transferred from the secondary memory to the RAM as and when required.
⇒ Execution of a program means that data is moved around in the CPU according to a well-detailed sequence by the programme.
⇒ Computer programs are written using special languages called programming languages.
⇒ There are several programming languages. Each language has its own ‘grammar’ called its syntax.
Types of Programming Languages
⇒ Machine language and the assembly language are examples of low-level languages.
⇒ A special program called Assembler converts all instructions into the binary format.
⇒ Because all such instructions must finally be converted to the binary form, all high-level languages have their own translation programs called compilers or interpreters.
⇒ Examples of popular high-level languages are C, C++, JAVA, Pascal, Fortran etc.
Software
⇒ Software relates to set of programs. The software controls the computer hardware parts and make them operational. In other words, it governs the operations of a computer system.
⇒ Software is a general term used for all computer programs. This distinguishes programs from the physical components of the computer, which are collectively called the hardware.
⇒ Software is generally divided into two kinds of programs: Application programs and System’s programs.
⇒ Applications programs are programs that permit the computer to be used as a tool for some specific tasks.
⇒ A common term used for special text editors is word processors.
⇒ Another popular type of application programs is the Data Base Management Systems (DBMS).
⇒ The most important system’s program is an operating system.
⇒ Operating systems help users interact with the computer.
⇒ Unix, MS-DOS, Linux, Windows, Mac OS are some of the most popular operating systems used by contemporary computers.
Glossary
Active Cell: The cell in MS Excel with dark boundary is called the active cell.
ALU: It stands for Arithmetic Logic Unit. All calculations in computer are done here.
Application Software: It is designed to perform some specific applications such as payroll, word processing, graphics etc.
Batch Processing : Data are processed in a batch.
BIOS: It stands for Basic Input Output System. This program is stored in ROM.
Bit: It is the short form of Binary Digit.
Boot Loader : It reads the main portion of the operating system from secondary memory.
Browsing: Viewing webpages on the website.
Byte : One byte is a collection of 8 bits.
Cell: Cells are boxes created by the intersection of rows and columns.
Cell Pointer : The boundary of active cell is called cell pointer.
Copyright: It means the material and information are the personal property of the owner or producer.
Counter feiting It is a process of making and distributing illegal copies of software packages.
Cracker A cracker is a person who breaks into a computer system to steal the information as programs for unauthorized use.
CU: It stands for Control Unit. It controls the computer system.
Data: Data are raw facts and figures.
Database: It is a collection of files. Data remains in an organized form in a database.
Data Capture: It is a process of collecting or capturing data from a site or a source.
Data Manipulation : Captured data are manipulated to produce information.
Data processing: It is the process to get meaningful information from data.
DBMS: It stands for Database Management System. It is a software package to manage database.
DHTML: It stands for Dynamic Hyper Text Markup Language. It is used to create dynamic content on web pages.
Dial Up Networking It is the method by which a computer is connected to the Internet using telephone.
DOS: It stands for Disk Operating System. It is an operating system.
Downloading: Process of transferring files from internet to computer memory.
Ethics: Ethics are rules and beliefs.
Fields: A field in database is a collection of bytes that contain data about an item.
File: A file is a collection of related records.
GML: It stands for General Mark-up Language.
Hacker: Ahacker is a person who breaks into a computer system to get access the information stored there.
HTML: It stands for Hyper Text Markup Language. It is used to create web-pages.
IAB It stands for Internet Activities Board which was formed in 1983. It is now called as Internet Architectural Board.
IAS: It stands for Internet Application Software also known as Browsers.
IETF: It stands for Internet Engineer Task Force.
IRTF: It stands for Internet Research Task Force.
ISP It stands for Internet Service Provider.
Internet Society: It was formed in 1992 to promote the use of Internet.
Input Unit: It is a part of computer system and used to enter data.
Linux: It is a Unix like Operating System with graphical user interface.
MAC OS: It is an Operating System used in Macintosh Computer, developed by Apple.
Modem It is a device to connect different computer systems to the internet using telephone or cable lines.
MU: It stands for Memory Unit. It is used to store data.
Online Processing : It is used when data are coming continuously without delay.
Operating Unit: It is used to take output from the computer.
Operating System: It is an interface between the human user and the computer hardware.
Piracy: It is the illegal reproduction and distribution of software application.
Primary Key: It is a field with unique value for each record.
Primary Memory: It is the main memory of a computer system.
Query: It is used to extract information from a
Range of Cells: It is group of neighbouring cells that touch each other.
RDBMS: It stands for Relational Database Management System.
Record: It is the collection of related fields
Secondary Memory: It is the permanent memory of the computer.
Software: It relates to sets of programs.
SOLARIS: It is a Unix like Operating System developed by Sun Microsystems.
Sorting: It is arranging of data in order.
System Software: It performs the basic functions that are necessary to operate a computer system.
Tag: It is part of HTML. It determines the way, the browser displays text in a Web Page.
Unix It is a powerful multiuser operating system. It uses command line user interface.
Virus: It is a harmful computer program.
Some Memorable Facts
⇒ A computer is a data processing machine.
⇒ It has two main parts: hardware and software.
⇒ Hardware comprises of the physical units of a computer system.
⇒ Software is a set of programs.
⇒ Both hardware and software together make a computer system functional.
⇒ Data are raw facts and figures.
⇒ An operating system is an interface between the user and the computer hardware.
⇒ An operating system manages computer resources.
⇒ An operating system performs different functions.
⇒ An operating system is responsible for process management, file management, etc.
There are many kinds of operating system.
⇒ Some popular operating systems are DOS, UNIX, Windows, LINUX, Mac OS etc
⇒ The Windows Explorer program is more efficient for viewing folders in Windows.
⇒ Windows Explorer is divided vertically into two parts or two panes.
⇒ The left side pane displays disk drives and folders in a hierarchical order.
⇒ The right pane displays the contents of the folder/ drive that is selected on left side pane.
⇒ The process of linking text values Most popular online in a series within a formula is Shopping Websites called ‘concatenation’.
⇒ The computer is a data processing machine.
⇒ Data processing involves some activities like data computing data manipulation and information management.
⇒ A database is a collection of interrelated data.
⇒ Computers are very useful for maintaining databases. collection of data items
⇒ A relational database is a organized as a set of formally described tables from which data can be accessed or reassembled in many different ways without having to reorganize the database tables.
⇒ MS Access is a powerful program to create and manage our databases.
⇒ A table is a collection of data about a specific topic.
⇒ A form is a graphical representation of a table.
⇒ A report is a presentation of data in a printed format.
⇒ We can create mailing labels for your database using MS Access.
⇒ Internet is the network of computer networks with millions of computer attached to it.
⇒ The Internet was originally developed by the US Department of Defence.
⇒ ‘The World Wide Web’ was invented by-Tim Berners – Lee.
⇒ FAT 32 and NTFS are the two major file systems in Microsoft Windows.
⇒ Websites are files in servers, which are powerful computers.
⇒ Websites contain pages called Web Pages.
⇒ The collection of all websites is called World Wide Web or WWW.
⇒ Hyper text was first coined by Ted Nelson in 1960s.
⇒ HTML is a markup language. It is used to create Web Pages. It uses commands called Tags.
⇒ Text editors are used to compose HTML documents. HTML documents are viewed in Web browsers.
⇒ In the Photoshop toolbox, the tools are grouped by type.
⇒ Some of the tool icons have a tiny black triangle in the lower-right corner of their icons. This means that there are more tools of the same general kind available on a et pop-up menu.
⇒ Most Popular Mobile Operating System is Android, followed by iOS & Windows.
⇒ Versions of Android (old to new) are: Cupcake → Donut → Eclairs → Froyo → Ginger Bread → Honeycomb → Ice Cream Sandwich → Jelly Beans → Kit-kat→ Lollipop →Marshmallow → Nougat →Oreo →Pie→Android 10 → Android 11.
⇒ Coding is the process of writing out computer les instructions.
⇒ Four major digital initiatives into push e-education by the govt. are Swayam, Swayam Prabha, National Academic Depository and National Digital Library.
⇒ Oracle is a database software.
⇒ Speed of Computer (or Clock speed) is measured in Hertz (Hz).howto sell bo 45
⇒ Speed of Modern Processors are often measured in Gigahertz (GHz).
⇒ Speed of communication over a data channel is measured in ‘Baud’.
⇒ DHCP (Dynamic Host Configuration Protocol is a network management protocol used on TCP/IP networks to provide quick, automatic and central management for the distribution of IP addresses within the network.
⇒ A Social Network can be represented as graph.
⇒ IPv6 protocol defines on IP address of 128 bit.
⇒ Junk email is called ‘spam’.
⇒ Cloud Computing – On demand delivery of computer power, database storage, applications and other IT resources through a cloud services platform mainly via the internet. In other words it is a distributed computer architecture that provides software, infrastructure and platforms just as required by applications/users.
⇒ Spreadsheet/MS Excel is appropriate for performing numerical and statistic calculations.
⇒ CAD/CAM systems are based on Interactive Computer Graphics.
⇒ Data Encryption Standard (DES) is an implementation of a Feistel Cipher. It uses 16 round Feistel structure and the block size is 64 bits.
⇒ Orthographic 3D Projection (a form of parallel projection) is a means of representing 3D objects in 2D.
⇒ The Banker algorithm, sometimes referred as the detection algorithm is a resource allocation and deadlock avoidance algorithm developed by Edsger W. Dijkstra.
⇒ Gateway is used to connect two different networks using different protocols.
⇒ A half byte is known as ‘Nibble’ (consists 4 bits).
⇒ MS Excel from Version 8.0 to 11.0 could handle 65,536 rows and 256 columns but later Version 12.0 can handle 10,48,576 rows and 16,384 columns.
⇒ The robot, named Pepe, was recently used by pupils at a primary school in Kerala. A collaboration between researchers from the UK and India has resulted in this newrobot which encourages children to wash their hands.
⇒ India’s first indigenously developed payment ecosystem for transport, based on National Common Mobility Card (NCMC) standards, was launched on 4th March, 2019.
⇒ Mobile App (VIGIL has been launched by Election Commission of India. cVIGIL is an innovativemobile application for citizens to report Model Code of Conduct and Expenditure violations during the elections.
⇒ VISHWAS is acronym for Video Integration and State Wide Advanced Security. First of its kind project in the country, VISHWAS is a major e-governance initiative. The project aims at improving Law and Order Management, Proactive traffic management and control, Crime detection through video analytics and Post incident Investigation and video forensics.
⇒ Agutter margin adds extra space to the side margin, top margin, or inside margins of a document that you plan to bind. Agutter margin helps ensure that text isn’t obscured by the binding.
⇒ TAG Heuer, a premium watchmaker, has associated with Google to develop a smart luxury watch.
⇒ Arintegrated circuit (IC) is small chip that can function as an amplifier, oscillator, timer, microprocessor, or even computer memory. An IC is usuallymade of silicon that can hold anywhere from hundreds to millions of transistors, resistors and capacitors.
⇒ World Wide Web: First Web browser was developed in the form of hyperlinked applications during the mid and late 1980s, and following these,Tim Berners-Lee is credited with developing, in 1990, both the first web server, and the first web browser, called World Wide Web (without spaces) and later renamed Nexus.
⇒ Windows 10 was released as a preview on 1st October, 2014. Windows 11 has been released on 5th October, 2021.
Computer Miscellaneous Add
⇒ QUBIT is the basic unit of Quantum information.
⇒ Simply put, cloud computing is the delivery of computing services including servers, storage, databases, networking, software, analytics, and intelligence-over the Internet (“the cloud”) to offer faster innovation, flexible resources, and economies of scale.
⇒ The form of information signal used in the sending fax is analogue signal and email uses digital signal.
⇒ According to IBM – Blockchain is a shared, immutable ledger that facilitates the process of recording transactions and tracking assets in a business network. An asset can be tangible (a house, car, cash, land) or intangible (intellectual property, patents, copyrights, branding).
⇒ Virtual Keyboards protect the computer against Keylogger programs, Password theft, Spywares, Trojan programs etc.
⇒ An e-mail that appears to originate from one source but actually has been from another is called Phishing.
⇒ Bus, Star and Grid are common network topologies while Grid is not a common network topology.
⇒ A router is used to transfer data packets between two computer networks.
⇒ A Database that contains the names and address of various hosts on internet is called Domain Name System.
Miscellaneous
⇒ QUBIT is the basic unit of Quantum information.
⇒ Simplyput,cloud computing is the delivery of computing services including servers, storage, databases, networking, software, analytics, and intelligence-over the Internet (“the cloud”) to offer faster innovation, flexible resources, and economies of scale.
⇒ The form of information signal used in the sending fax is analogue signal and email uses digital signal.
⇒ According to IBM – Blockchain is a shared, immutable ledger that facilitates the process of recording transactions and tracking assets in a business network. An asset can be tangible (a house, car, cash, land) or intangible (intellectual property, patents, copyrights, branding).
⇒ Virtual Keyboards protect the computer against Keylogger programs, Password theft, Spywares, Trojan programs etc.
⇒ An e-mail that appears to originate from one source but actually has been from another is called Phishing.
⇒ Bus, Star and Grid are common network topologies while Grid is not a common network topology.
⇒ A router is used to transfer data packets between two computer networks.
⇒ A Database that contains the names and address of various hosts on internet is called Domain Name System.
Some Important Initiatives of the Government
e-Pramaan: Framework for e-Authentication for public services. The objective is to deliver the government services to its intended recipients in a secure manner, as well as to build citizens’ trust in online environment, which is always prone to identity thefts and other associated risks. Meity has made e-Pramaan available for public usage with the help of C-DAC, Mumbai.
Online e-Sign (e-Hastakshar): This facility is an online digital signature service. It was formally launched in 2015. It is an online electronic signature service, which can be integrated with service delivery applications via an Application Programming Interface (API) to facilitate an e-Sign user to digitally sign a document. e-Sign service facilitates instant signing of documents online by citizens in a legally acceptable form.
National Knowledge Network National Knowledge Network (NKN) was established in 2010. The objective of the NKN is to interconnect all institutions of higher learning and research with a high-speed data communication network to facilitate knowledge sharing and collaborative research. NKN is the only network globally, that carries research and evaluation, internet and e-Governance traffic as three independent verticals under one umbrella. In addition to educational institutes, NKN connects all SDCs (State Data Centre), NDCs (National Data Centre), Ministries and departments across the government.
UMANG: Unified Mobile Application for New-Age Governance (UMANG) has been developed and launched in 2017 as a single mobile platform to deliver major government services. UMANG’s core platform is integrated with Adhaar, DigiLocker, PayGov, Rapid Assessment System (RAS), etc. Citizens can access pan India government services from the central government, State government, local bodies and their agencies. It supports 12 Indian languages, in addition to English and has been hosted on cloud.
Digital Locker (Digilocker): Digital Locker is a key initiative under Digital India, the Government of India’s flagship program aimed at transforming India into a digitally empowered society and knowledge economy. Targeted at the idea of paperless governance, Digital Locker is a platform for insurance and verification of documents and certificates in a digital way, thus eliminating the use of physical documents. Indian residents, who signup for a DigiLocker account get a dedicated cloud storage space. Organisations that are registered with Digital Locker can push electronic copies of documents and certificates (e.g. driving license, school certificates) directly into citizens’ lockers. Citizens can also upload scanned copies of their legacy documents in their accounts. These legacy documents can be electronically signed using the eSign facility.
PRAGATI: The video conferencing facility PRAGATI (Pro-Active Governance And Timely Implementation) as a part of Digital India programme, e-Governance Reforming Government through Technology, was launched in 2015. This enables faster implementation of central level schemes /projects, state level projects and resolutions of Grievances between state and central level departments.
Direct Benefit Transfer: The Direct Benefits Transfer (DBT) program envisages a switch from the present electronic transfer to the bank accounts of the beneficiary to transfer of benefits directly to Adhaar seeded bank accounts of the beneficiaries. The scheme is being headed by DBT Mission.
e-Way Bill: e-Way Bill Application, provides a selfservice platform to tax payers and transporters to generate single e-Way bill for movement of goods from one place to another, as per GST Rules.
Unique Identification Authority of India (UIDAI) : The Unique Identification Authority of India (UIDAI) was established in 2009, as an attached office to the Planning Commission now an attached office of Ministry of Electronics and IT with a vision, “To empower residents of India with a unique identity and a digital platform to authenticate anytime anywhere”. A key objective of Adhaar Program is to provide an identity infrastructure for delivery of various social welfare programs and for effective targeting of welfare services.
National Informatics Centre : National Informatics Centre (NIC) was established in 1976, and has since emerged as a “Prime builder” of e-government/ e-governance applications upto the grassroot level as well as a promoter of digital opportunities for sustainable development. NIC, through its ICT network, “NICNET”, has institutional leakages with all the ministries / departments of the central government, 37 state governments / union territories and about 650+ district administration of India.
Software Technology Parks : Software Technology Parks of India (STPI) was setup in 1991 as an autonomous society under the MeitY. STPI’s main objective has been the promotion of software exports from the country. It acts as single-window in providing services to the software exporters.
Centre for Department of Advance Computing : Centre for Department of Advance Computing (C-DAC)hasemerged as a premier R&D organisation and IT&E (Information Technologies and Electronics). In the country working on strengthening national technological capabilities in the context of global developments in the field and responding to change in the market in selected foundation areas. It is an institution for high-end Research & Development (R&D). [Source: INDIA 2021]
Tele-density: Tele-density, which denotes the number of telephones per hundred populations, is an important indicator of telecom penetration. Overall tele-density in the country was 88.51% at the end of July 2021. The rural teledensity was 60.33% while that in urban areas it was 141.62%.