Sir mumtaz kolai lectures
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Transcript of Sir mumtaz kolai lectures
Introduction to ICT
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COMPUTERS IN THE HOME
Computers used for a variety of tasks:Looking up information and newsExchanging e-mailShopping and paying billsWatching TV and videosDownloading music and moviesOrganizing digital photographsPlaying gamesTelecommuting
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COMPUTERS IN THE HOME
ConvergenceThe computer has become the central part of
home entertainmentDual-mode mobile phones
Wireless networkingComputers can be used in nearly any location
Smart appliancesTraditional appliances with built-in computer or
communication technology Smart homes
Household tasks are monitored and controlled by a main computer in the house
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COMPUTERS IN THE HOME
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COMPUTERS IN EDUCATION
Many students today have access to computers either in a classroom or a computer lab
Colleges and universities are even more integratedWireless hotspots allow usage of personal
laptops to connect to the college networkSome colleges require a computer for
attendance Distance learning
Students participate from locations other than the traditional classroom setting using computers and Internet access
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COMPUTERS IN EDUCATION
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COMPUTERS ON THE JOB
Computers have become a universal on-the-job tool for decision-making, productivity, and communicationUsed by all types of employeesUse by service professionals is growingUsed extensively by the militaryEmployees in all lines of work need to
continually refresh their computer skills
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COMPUTERS ON THE JOB
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COMPUTERS ON THE GO
Computers are encountered in nearly every aspect of daily lifeATM transactionsPortable computers or mobile devicesM-commerce systemsGPS systems
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COMPUTERS ON THE GO
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WHAT IS A COMPUTER AND WHAT DOES IT DO?
Computer: A programmable, electronic device that accepts data, performs operations on that data, and stores the data or results as needed Computers follow instructions, called programs,
which determine the tasks the computer will perform
Basic operations Input: Entering data into the computer Processing: Performing operations on the data Output: Presenting the results Storage: Saving data, programs, or output for
future use Communications: Sending or receiving data
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WHAT IS A COMPUTER AND WHAT DOES IT DO?
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DATA VS. INFORMATION
Data Raw, unorganized factsCan be in the form of text, graphics, audio,
or video Information
Data that has been processed into a meaningful form
Information processingConverting data into information
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COMPUTERS THEN AND NOW
The history of computers is often referred to in terms of generations
Each new generation is characterized by a major technological development
Early computers (before 1946)Abacus, slide rule, mechanical
calculatorPunch Card Tabulating Machine
and Sorter
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COMPUTERS THEN AND NOW
First-generation computers (1946-1957) Enormous and powered by vacuum tubes Used a great deal of electricity, and
generated a lot of heat ENIAC and UNIVAC
Second-generation computers (1958-1963) Used transistors Computers were smaller, more powerful,
cheaper, more energy-efficient, and more reliable
Punch cards and magnetic tape were used to input and store data
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COMPUTERS THEN AND NOW
Third-generation computers (1964-1970)Used integrated circuits (ICs)Keyboards and monitors introduced
Fourth-generation computers (1971-present)Use microprocessors IBM PC, Apple MacintoshUse keyboards, mice, monitors, and printersUse magnetic disks, flash memory, and optical
disks for storageComputer networks, wireless technologies,
Internet introduced
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COMPUTERS THEN AND NOW
Fifth-generation (now and the future)May be based on artificial intelligence (AI)Likely use voice and touch inputMay be based on optical computers and
utilize nanotechnology( atomic, Molecular, Super molecular)
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COMPUTERS THEN AND NOW
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HARDWARE
Hardware: The physical parts of a computer Internal hardware
Located inside the main box (system unit) of the computer
External hardware Located outside the system unit Connect to the computer via a wired or wireless
connectionThere is hardware associated with all five
computer operations
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HARDWARE
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HARDWARE
Input devicesUsed to input data into the computerKeyboards, mice, scanners, cameras,
microphones, joysticks, touch pads, touch screens, fingerprint readers, etc.
Processing devicesPerform calculations and control computer’s
operationCentral processing unit (CPU) and memory,
microcontrollers Output devices
Present results to the userMonitors, printers, speakers, projectors, etc.
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HARDWARE
Storage devicesUsed to store data on or access data from
storage mediaHard drives, CD/DVD discs and drives, USB
flash drives, etc. Communications devices
Allow users to communicate with others and to electronically access remote information
Modems, network adapters, etc.
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HARDWARE
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SOFTWARE
Software: The programs or instructions used to tell the computer hardware what to doSystem software: Operating system starts up
the computer and controls its operation Without OS computer cannot function Boots the computer and launches programs at the
user’s direction Most use a GUI to interact with the user via
windows, icons, menus, buttons, etc. Windows, Mac OS, Linux, etc.
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SOFTWARE
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APPLICATION SOFTWARE
Application software: Performs specific tasks or applications Creating letters, budgets, etc. Managing inventory and customer databases Editing photographs Scheduling appointments Viewing Web pages Sending and receiving e-mail Recording / playing CDs/DVDs Designing homes Playing games
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SOFTWARE
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COMPUTER USERS AND PROFESSIONALS
Computer users (end users): People who use a computer to obtain information
Computer professionals include:ProgrammersSystems analystsSecurity specialists
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COMPUTERS TO FIT EVERY NEED
Six basic categories of computers:Embedded computersMobile devicesPersonal computersMidrange serversMainframe computersSupercomputers
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EMBEDDED COMPUTERS
Embedded computer: Embedded into a product and designed to perform specific tasks or functions for that product
Cannot be used as general-purpose computers
Often embedded into:Household appliancesThermostatsSewing machinesCars
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MOBILE DEVICES Mobile device: A very small
device with some type of built-in computing or Internet capability
Typically based on mobile phones
Typically have small screens and keyboards
Examples:Smart phonesHandheld gaming devicesPortable digital media players
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PERSONAL COMPUTERS (PCS)
Personal computer: A small computer designed to be used by one person at a timeAlso called a microcomputerRange in size from desktop computers to
UMPC’sCan use tower case, desktop caseCan be PC-compatible or MacintoshNot designed to be portable
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PORTABLE COMPUTERS
Notebook (laptop) computers Tablet computers: Can
be slate tablets or convertible tablets
Ultra-mobile PCs (UMPCs):Handheld computers
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THIN CLIENTS AND INTERNET APPLIANCES
Thin client or network computer (NC): Device designed to access a network for processing and data storageLower cost, increased security and easier
maintenanceLimited or no local storageNot able to function as a computer if network is
down Internet appliance: Specialized network
computer designed for Internet access and/or e-mail exchangeCan include Internet-enabled gaming consoles
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MIDRANGE SERVERS
Midrange server: A medium-sized computer used to host programs and data for a small networkUsers connect via a network with a
computer, thin client, or dumb terminalMay consist of a collection
of individual circuit boards called blades
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MAINFRAME COMPUTERS Mainframe computer: Powerful computer used
by several large organizations to manage large amounts of centralized data Standard choice for large organizations, hospitals,
universities, large businesses, banks, government offices
Located in climate-controlled data centers and connected to the rest of the company computers via a network
Larger, more expensive, and more powerful than midrange servers
Usually operate 24 hours a day Also called high-end servers or enterprise-class
servers
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MAINFRAME COMPUTERS
SUPERCOMPUTER
Supercomputer is a broad term for one of the fastest computer currently available.
Super computers were designed and built to work on extremely large jobs that could not be handled by no other types of computing systems.
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SUPERCOMPUTERS
Supercomputer: Fastest, most expensive, most powerful type of computerGenerally run one program at a time, as fast
as possibleCommonly built by connecting hundreds of
smaller computers, supercomputing clusterUsed for space exploration, missile guidance,
satellites, weather forecast, oil exploration, scientific research, complex Web sites, decision support systems, 3D applications, etc.
SUPERCOMPUTER (CONT’D)Supercomputers speed are measured in floating point operations per second (FLOPS) in units of megaflops (MFOPS) gigaflops (GFLOPS) teraflops (TFLOPS)
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SUPERCOMPUTERS
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COMPUTER NETWORKS AND THE INTERNET
Computer network: A collection of hardware and other devices that are connected together. Users can share hardware, software, and data Users can communicate with each other
Network servers: Manage resources on a network
Clients: Access resources through the network server
Computer networks exist in many sizes and types Home networks School and small business networks Large corporate The Internet
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COMPUTER NETWORKS AND THE INTERNET
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WHAT ARE THE INTERNET AND THE WORLD WIDE WEB? Internet: The largest and most well-known
computer network in the world Individuals connect to the Internet using an
Internet service provider (ISP) World Wide Web: One resource (a vast
collection of Web pages) available through the InternetWeb sites contain Web pages stored on Web
serversWeb pages viewed using a Web browser
(Internet Explorer, Chrome, Safari, Firefox, Opera, etc.)
A wide variety of information is available through the Web
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ACCESSING A NETWORK OR THE INTERNET
Need a modem or network adapter Some networks require a username and password Internet connections can be:
Direct (always-on) connections Dial-up connections
Internet addresses are used to access resources on the Internet IP address: Numeric address that identifies computers
(207.46.197.32) Domain name: Text-based address that identifies computers
(microsoft.com) Uniform resource locator (URL): Identifies Web pages
(http://twitter.com/jobs/index.html) E-mail address: Identifies people for e-mail exchange
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COMPUTERS AND SOCIETY
The vast improvements in technology over the past decade have had a distinct impact on daily life, both at home and at work
Many benefits of a computer-oriented society:Ability to design products before construction
leads to safer productsEarlier medical diagnosesDocuments e-mailed or faxed in momentsDownload information, music, programs,
movies, and more on demand
COMPUTERS AND SOCIETY
Computer-oriented society also has risks Computer viruses and malware Identity theft and phishing Privacy issues
Information Integrity Check your source, not all information on the
Internet is accurate.
(c) Yngvi Bjornsson 48CMPUT101 Introduction to Computing
DESIGNING COMPUTERS
All computers more or less based on the same basic design, the Von Neumann Architecture!
(c) Yngvi Bjornsson 49CMPUT101 Introduction to Computing
THE VON NEUMANN ARCHITECTURE
Model for designing and building computers, based on the following three characteristics:
1) The computer consists of four main sub-systems:
Memory ALU (Arithmetic/Logic Unit) Control Unit Input/Output System (I/O)
2) Program is stored in memory during execution.3) Program instructions are executed
sequentially.
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THE VON NEUMANN ARCHITECTURE
Memory
Processor (CPU)
Input-OutputControl Unit
ALUStore data and program
Execute program
Do arithmetic/logic operationsrequested by program
Communicate with"outside world", e.g. • Screen• Keyboard• Storage devices • ...
Bus
18th August, 2005 CS431 Course Presentation 51
BOOTING OF A COMPUTER
SYSTEM
WHY IS BOOTING REQUIRED ? Hardware doesn’t know where the operating
system resides and how to load it. Need a special program to do this job –
Bootstrap loader. E.g. BIOS – Basic Input Output System.
Bootstrap loader locates the kernel, loads it into main memory and starts its execution.
In some systems, a simple bootstrap loader fetches a more complex boot program from disk, which in turn loads the kernel.
CS431 Course Presentation 5318th August, 2005
HOW BOOT PROCESS OCCURS ? Reset event on CPU (power up, reboot)
causes instruction register to be loaded with a predefined memory location. It contains a jump instruction that transfers execution to the location of Bootstrap program.
This program is form of ROM, since RAM is in unknown state at system startup. ROM is convenient as it needs no initialization and can’t be affected by virus.
BIOS INTERACTION
CS431 Course Presentation 5518th August, 2005
TASKS PERFORMED AT BOOT UP Run diagnostics to determine the state of
machine. If diagnostics pass, booting continues.
Runs a Power-On Self Test (POST) to check the devices that the computer will rely on, are functioning.
BIOS goes through a preconfigured list of devices until it finds one that is bootable. If it finds no such device, an error is given and the boot process stops.
Initializes CPU registers, device controllers and contents of the main memory. After this, it loads the OS.
BIOS SETUP
BOOT PROCEDURE
TASKS PERFORMED AT BOOT UP (CONTD) On finding a bootable device, the BIOS
loads and executes its boot sector. In the case of a hard drive, this is referred to as the master boot record (MBR) and is often not OS specific.
The MBR code checks the partition table for an active partition. If one is found, the MBR code loads that partition's boot sector and executes it.
The boot sector is often operating system specific, however in most operating systems its main function is to load and execute a kernel, which continues startup.
CS431 Course Presentation 5918th August, 2005
BOOTING AND ROM System such as cellular phones, PDAs and
game consoles stores entire OS on ROM. Done only for small OS, simple supporting hardware, and rugged operation.
Changing bootstrap code would require changing ROM chips. EPROM – Erasable Programmable ROM.
Code execution in ROM is slower. Copied to RAM for faster execution.