Module-1.2.pdf

CLASSIFICATIONS OF COMPUTER According to Size and Processing Speed a) Supercomputers b) Mainframe computers c) Minicomputers d) Microcomputers (Personal Computers) SUPERCOMPUTERS The fastest type of computer. They are very expensive and employed for specialized applications that...

CLASSIFICATIONS OF COMPUTER According to Size and Processing Speed a) Supercomputers b) Mainframe computers c) Minicomputers d) Microcomputers (Personal Computers) SUPERCOMPUTERS The fastest type of computer. They are very expensive and employed for specialized applications that require immense amounts of mathematical calculations. They are mainly used for: weather forecasting animated graphics fluid dynamic calculations nuclear energy research petroleum exploration Examples: NEC Earth Simulator IBM ASCI White TERASCALE Computing System TERA Supercomputer NERSC IBM SP RS/600 MAINFRAME COMPUTERS A very large and expensive computer capable of supporting hundreds, or even thousands, of users simultaneously. They are slower and less than supercomputers. They support hundreds or thousands of users at a time. They are used as e-commerce and web servers and in large organizations, banks, universities and airlines as databases. Examples: IBM 3090 Andhal 5890 MINICOMPUTERS A midsized computer. In general, a minicomputer is a multi- processing system capable of supporting from 4 to about 200 users simultaneously. They are also known as midrange computers. They are used in medium size business, education and government departments and are also used as servers on the network environment. Example: IBM’s AS/400e MICROCOMPUTERS Is generally a synonym for the more common term, Personal Computer or PC, a computer designed for an individual. It uses microprocessor technology to input, manipulate, store and output data. Business use personal computers for word processing, accounting, desktop publishing, and for running spreadsheet and database management applications. Examples: Apple II (introduced by Apple Computer in 1977) IBM PC (IBM’s first personal computer) TWO CLASSIFICATIONS OF MICROCOMPUTERS PERSONAL COMPUTER It is widely popular with people of all lifestyle because they are powerful, affordable and easy to use. PORTABLE COMPUTER Include laptops or notebooks, sub-notebook, tablet computer and personal digital assistants. They are small enough to move easily from one place to another and they can operate on batteries. They are popular with people who travel and need computing power on the go. Laptop/Notebook Computer A small portable computer. Small enough that it can sit on your lap. Use a variety of techniques, known as flat-panel technologies, to produce a lightweight and non- bulky display c. screen. Subnotebook Computer Slightly lighter and smaller than a full-sized notebook computer. Have smaller keyboard and screen but are otherwise equivalent to notebook computers. Personal Digital Assistant A handheld device that combines computing, telephone/fax, and networking features. It can function as a cellular phone, fax sender, and personal organizer. Most PDAs began as pen-based, using stylus rather than a keyboard for input. Tablet PC Provides the full power and functionality of today’s notebook PC’s Design for a fully equipped personal computer that allows a user to take notes using natural handwriting on a stylus or digital pen. According to Data Handled a) Analog computers b) Digital computers c) Hybrid computers ANALOG COMPUTERS Analog computers operate on mathematical variables in the form of physical quantities that are continuously varying. For example, temperature, pressure, voltages, etc. Famous examples of analog computers are the Planimeter, the nomogram, operational amplifiers, mechanical integrators, slide rules, tide predictors, electric integrators that solve partial differential equations, electronic machines that solve ordinary differential equations, machines to solve algebraic equations, the Norden bomb sight, and neural networks. DIGITAL COMPUTERS Digital computers deal with mathematical variables in form of numbers that represent discrete values of physical quantities. The advantages of digital computers are that they are versatile, reprogrammable, accurate, and less affected by outside disturbances. In contrast to analog computers, digital machines work on numbers. Each variable is converted into numbers and each number into binary form, i.e., 0 and 1. It is this combination of 0 and 1 that does all the calculations. All modern computers, laptops, and calculators are all digital computers. HYBRID COMPUTERS A hybrid is a combination of digital and analog computers. It combines the best features of both types of computers. It has the speed of analog computer and the memory and accuracy of digital computer. Hybrid computers are used mainly in specialized applications where both kinds of data need to be processed. Computer used in hospitals to measure the heartbeat of the patient. Devices used in petrol pump. In scientific applications or in controlling industrial processes. According to Purpose a) General-purpose computers b) Special purpose computers (Dedicated computers) GENERAL-PURPOSE COMPUTERS It is capable of dealing to a variety of different problems and are able to respond to programs created to meet different needs. It is capable of storing different programs of instructions thus they can perform a variety of operations. Example is a Desktop Computer SPECIAL PURPOSE COMPUTERS (DEDICATED COMPUTERS) It is designed to perform one specific task. The programs are built into permanently in the machine and given task are performed very quick and efficient. Examples are computers used in monitoring nuclear reactions, outer space missions, oil explorations COMPONENTS OF A COMPUTER SYSTEM HARDWARE It is the physical equipment associated with a computer system. This is the tangible components of the computer system. Four Primary Components of a Computer Hardware System a) Input Devices b) Output Devices c) Storage Devices d) System Unit INPUT DEVICES Any hardware component that allows the user to enter data, execute commands and user responses into the computer. Basically, input devices are used for data entry. INPUT DEVICES Keyboard - the set of typewriter keys that enables you to enter data in a computer. Mouse - invented by Douglas Engelbert of Stanford Research Center in 1963, and pioneered by Zerox in 1970s, the mouse is a device that controls the movement of the cursor or pointer on a display screen. INPUT DEVICES Joystick - a device consisting of a handheld stick that pivots about one end and transmits its angle in two dimensions to a computer. It often used to control games, and usually have one or more push-buttons whose state can also be read by the computer. Light pen - a small, photosensitive device connected to a computer and moved by hand over an output display in order to manipulate information in the computer. Used in Personal Digital Assistant and Smart Board. INPUT DEVICES Microphone - allows the computer to receive and record sound. Necessary for voice recognition software and any software that needs to record sound. Digital camera - takes pictures without film and stores your snapshots as digital files in its memory. Later, you can transfer your picture files to your PC through cable. INPUT DEVICES Barcode reader - an optical scanning device that reads texts which have been converted into a special bar code or zebra stripes. Webcam - a digital camera capable of capturing images to a computer for transmission over the Internet or other network. INPUT DEVICES Drawing Tablet - is similar to a white board, except you use a special pen to write on it and it's connected to the computer. Then the word or image you draw can be saved on the computer. Scanner - an input device that takes in an optical image and digitizes it into an electronic image. This can be used to create a computerized version of a photo or illustration. 4 KINDS OF SCANNER Flatbed scanner - a scanner that provides a flat, glass surface to hold pages of paper, books and other objects for scanning. The scan head is moved under the glass across the page. Sheet-fed scanner - a scanner that allows only paper to be scanned rather than books or other thick objects. It moves the paper across a stationary scan head. 4 KINDS OF SCANNER Handheld scanner - a scanner that is moved across the image to be scanned by hand. Handheld scanners are small and less expensive than their desktop counterparts but rely on the dexterity of the user to move the unit across the paper. Drum scanner - A type of scanner used to capture the highest resolution from an image. Photographs and transparencies are taped, clamped or fitted into a clear cylinder. A light source that focuses on one pixel is beamed onto the drum and moves down the drum a line at a time. OUTPUT DEVICES Any hardware component that presents, displays, alters, or record output after it has left a computer’s system unit. OUTPUT DEVICES Monitor - it is the most popular output device. It receive signals from video card inside of the computer and gives the user a graphical or textual display. Speakers - are used to produce sounds, listen to music, play music and watch movies. Printer - create images on paper, plastic, cloth and other print media using technologies like ink transfer, heat transfer, chemical reactions and physical force. TYPES OF PRINTERS Laser Printer - uses toner and an internal laser to print. Inkjet or Bubble Jet Printers - uses ink to print. Usually available in color. Dot-Matrix Printer - creates characters by striking pins against an ink ribbon. Each pin makes a dot, and combinations of dots form characters and illustrations. STORAGE DEVICES These are important for keeping a document for later retrieval and use. TWO CLASSIFICATIONS OF STORAGE DEVICES: Primary Storage - is the main memory. In this memory, the data used from processing and the programs to be read are stored. ROM (Read Only Memory) - is a permanent memory. The instructions stored can be changed and will not get lost even if the power is switched off. RAM (Random Access Memory) - is a temporary memory. The information stored in it will get lost once the computer is switched off or the power is cut off. TWO CLASSIFICATIONS OF STORAGE DEVICES: Secondary Storage - is also called an external memory. Hard Disk - it is a magnetic disk in the system unit of a personal computer and is an external hard disk device. CD-ROM - is an optical disk format used to hold texts, graphics and sounds that are pre-recorded. It is small, flat metal-coated plastic disc, about 4.75 inches in diameter. It stores information by using a laser which creates pits on disc and is read by using another laser to read the light reflected from the pins. Flash Drives - is a type of compact USB memory drive that acts like a portable hard drive, letting you to store and transport computer data. SYSTEM UNIT Part of the computer which is responsible for accepting and processing the data brought in by the input devices, passing resulting information to the users via the output devices. COMPONENTS OF SYSTEM UNIT: Main Circuit Board - central nervous system. Also called motherboard. Port - is a connection from the main circuit board to a peripheral device such as keyboard, printer or a video monitor by means of a special cable. Also called interface. Expansion Slots - they are used to connect expansion cards to the main circuit board. An expansion card is a printed circuit card with circuitry that gives the computer additional capabilities. COMPONENTS OF SYSTEM UNIT: Central Processing Unit (CPU) - is the computer’s processing, control and internal storage circuitry. Bytes - unit of measurement in measuring memory Hertz - unit of measurement in measuring speed Bit - stands for binary digits. It is the basic unit of data recognized by the computer. 1 Byte= 8 bits 1 Kilobytes (KB) = 1024 bytes 1 Megabytes (MB) = one million bytes 1 Gigabytes (GB) = one billion bytes 1 Terabytes (TB) = one trillion bytes SOFTWARE It is the programs and data that a computer uses. The software provides the commands that tell the hardware what task to perform, what to read and write, how to send the end result (the output) to a monitor and/or printer. Kinds of Software a) Application Software b) System Software c) Utility Software APPLICATION SOFTWARE These are programs that people use to get their work done. APPLICATION SOFTWARE Word Processor - is a computer application used for the production (including composition, editing, formatting, and possibly printing) of any sort of printable material. - Examples: Microsoft Word, Microsoft Publisher Spreadsheet Software - presents business data in a grid of rows and columns. - Example: Microsoft Excel APPLICATION SOFTWARE Graphics and Presentation - is a computer software package used to display information, normally in the form of a slide show. - Example: Microsoft PowerPoint Database Software - a software that helps a user organize data in a way that allows fast and easy access to the data. - Examples: Microsoft Access, Oracle, MySQL APPLICATION SOFTWARE Games - involves interaction with a user interface to generate visual feedback on a video device. - Example: Solitaire Internet Browser - a software application that enables a user to display and interact with text, images, and other information typically located on a Web page at a website on the World Wide Web or a local area network. - Examples: Google Chrome, Microsoft Edge SYSTEM SOFTWARE The system software includes all programs used to operate and maintain the computer system. It controls all input/output functions and coordinates the flow of operations during processing. SYSTEM SOFTWARE Operating System - a set of computer programs that manage the hardware and software resources of a computer. - Examples: Windows, Linux Programming Languages - a software used to write or create other programs or software. - Examples: C/C++, Java, Visual Basic UTILITY SOFTWARE Also known as service program, service routine, tool, or utility routine. It is specifically designed to help manage and tune the computer hardware, operating system or application software, and perform a single task or a small range of tasks. Example: Virus Scanners PEOPLEWARE Are the users of the computer, they may be the system analysts, programmers, web developers, students, administrators, encoders or just a common personnel who in a way works with the computer. THANK YOU FOR LISTENING!