computer fundamentals module 3
DESCRIPTION
fundamentals of computer, generation of computersTRANSCRIPT
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 1/129
INTRODUCTION TO COMPUTERS
Definition
A computer is an electronic device that is used for information
processing. It accepts data and instructions, stores it in its memory,
process and gives the required results as output.
The word Computer is derived from the Latin word Compute that
means manipulate or calculate.
Input Processing Memory Output
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 2/129
CAPABILITIES
Input & Output
Processing
Huge Data Storage
CHARACTERISTICS
High Speed
Accuracy
Reliability
Versatility
Diligence
Storage Capacity
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 3/129
TYPES
Micro Computer.
Mini or Midrange Computer.Mainframe Computer.
Super Computer.
Micro Computer
Mini Computer
PC¶s are called as Home computers
or Desktop computers.
Mainframe Computer Example: VAX-8000, UNIVAS
1100/60, IBM-3033/3090 etc.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 4/129
Input
Unit
Primary Memory
Arithmetic and Logical Unit
Secondary Memory
Control Unit
Output
Unit
Memory
CPU
BLOCK DIAGRAM
SYSTEM UNIT
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 5/129
BASIC UNITS
Input Unit.
System Unit
Output Unit.
Input Unit.
Input unit is an external device that is connected to the
CPU. It is used to feed data and instructions for solving
the problem
Examples: Key Board, Mouse ,Scanner etc.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 6/129
System Unit.
Once the data and instructions are received from the input they are
stored and processed in the system unit.
The system unit further consists of two sub-units.
They are:
Central Processing Unit.
Memory Unit.
It is generally called CPU. Once the data and instructions are
received from the input device, they are to be processed in this
unit. So, it can be considered as the heart and brain of the
computer system. Further, the CPU consists at two importantfunctional units.
Control unit
Arithmetic and Logic unit
Central Processing Unit
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 7/129
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 8/129
Memory Unit
It is a storage device. The memory unit is a device where the data
and instructions fed by the used are stored.
Primary memory
Secondary memory
Cache Memory
Primary Memory
The place where the data and instructions are stored.
Temporary memory.
Semiconductor memory.
Read Only Memory - ROM Random Access Memory - RAM
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 9/129
Permanent memory. Stores large amount of information for a long time.
Backup memory or an auxiliary memory.
Examples : FDD, HDD & CDROM
Secondary Memory
Cache Memory
High-speed memory and placed between the CPU and the main
memory.
The data and instructions stored in it are accessed at a higher
speed.
User cannot access this memory. Its stores data and instructions that are currently to be executed.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 10/129
MAIN MEMORY
All instructions and data to beexecuted are stored temporarily
Access time is 80 ns
More capacity
Less costlier
CACHE MEMORY
Only goes instructions and data
that are immediately executed
are stored here.
Access time is 15 - 25 ns
Less capacity
More costlier
It is used to display the results obtained after execution of a
program. Whenever the user wants output from the computer,
The most commonly used display unit in the monitor.
Examples : Monitor, Printer, Plotters, Speakers etc.
Output Unit.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 11/129
LIMITATIONS
Non Intelligent.
Inactive.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 12/129
HARDWARE
Keyboard
It is the most common input device.
To enter both Alphanumerical &
character
Mechanical Typewriter Compatible Keyboards contain 108
Keys
Input Devices
The term hardware refers to the physical devices that you can see and
touch in a computer system. Thus, the input, output, storage, control
and processing devices are hardware.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 13/129
Mouse
It is a small hand held pointing
device connected. It has a rotating ball at the bottom
and has two click buttons on the top.
Light Pen
It is a pencil shaped device. It is
used to select screen co-ordinates
by detecting the light coming form
illuminated points on the CRT
(Cathode Ray Tube) screen.
Joy Stick
It is a small rod (lever or stick)mounted on a rolling ball. This rod is
used to control the screen cursor.
It is mainly used for playing
Computer or TV games.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 14/129
Scanner
It is used to acquire (scan) both
character and graphics required for image processing or character
recognition.
It scans the image of a photograph
or written information and
communicates it to the CPU
Microphone
It is an input device, used to feed the
audio input to the computer.
The microphone is directlyconnected to the CPU.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 15/129
Output Devices
Monitor
It is an electronic device
Which is used to monitor the work
process taking place in the computer.
The output which is monitored on the
monitor screen is known as the softcopy.
Speaker
Listen to the audio output sent by theprocessor.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 16/129
Printers
A printer is an electromechanical device which signals from the
computer and acts accordingly.
Characteristics
Speed
Quality of output
Printer memory (Buffer)
Type
Fonts, etc.,
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 17/129
Plotters
A device used to produce graphical
output. They are employed for plotting graphs,
charts and other designs on paper.
Flat Bed Plotter Drum Plotter
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 18/129
Secondary Storage Devices
Floppy Disk
Floppy diskette
Floppy is soft and flexible and disk
means circular thing
A floppy disk plate is a special polymer
called Mylar Stores in Tracks & Sectors
Slno Size Specification Capacity
1. 5.25 Inch DSDD
DSHD
360 KB
1.22 MB
2. 3.5 Inch DSDD
DSHD
720 KB
1.44 MB
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 19/129
Hard Disk
A hard disk is a group of round flat metal
plates which are coated with magnetic material Data is recorded on both the surfaces of a disk
The speed is generally in the range of 2400 ±
4700 rpm Stores in Tracks & Sectors
Stores in Tracks & Sectors.
The disk in the hade disk is called as Platter
and made up of semiconductor material
Advantages
Random access ± Data is located and accessed
directly for reading and writing
Reusability ± Data stored on these disks can
be used repeatedly.
Durability - They are less prone to damage
Disadvantages
Costlier as compared to magnetic tape
Hard disks are of heavy weight as compared
to magnetic tapes
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 20/129
CD-ROM
CD-ROM stands for Compact Disk-Read Only Memory.
Circular plastic plate which is coated
with a highly reflective material.
The data is recorded on this disk by
focusing a laser beam on the surface of
the disk The storage capacity of CD-ROM is 700
to 900 MB.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 21/129
SOFTWARE
Set of Programs is an software.
Set of instructions is an program
Classification of Software
Software
Application
Software
System
Software
Utility
Software
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 22/129
Application Software
It is a general purpose program or a collection of programs written bythe users to solve a particular problem, in his/her area of interest.
For example: Payroll, Inventory system, Student Information System,
Library Management System etc.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 23/129
System Software
It is a collection of programs written for computer system management. These programs are developed by the manufacturer. They are supervisory programs and
help in executing the user¶s programs effectively. We can classify system software
into the following three types.
A) SYSTEM MANAGEMENT PROGRAMS: -
Programs that manage the hardware, software, network and data
resources of the computer systems during the execution of the variousinformation-processing job of users. Eg. All Operating systems like Windows
98, 2000, XP,Unix, Linux, Novel Netware etc.
B) SYSTEM DEVELOPMENT PROGRAMS: -
Programs that help users develop information system programs and
procedures and prepare user programs for computer processing. Eg. C, C++,VB, Oracle, JAVA etc.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 24/129
Managing Data Resources
Data Concepts
Character: The most basic logical data element is the
character, which consists of a single alphabetic, numeric or
other symbol.
Field: It consists of grouping of related characters. Ex.
Name, number, object, place, event etc.
Record: It represents grouping of related data fields. Thus, a
record represents a collection of attributes that describe anentity.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 25/129
File: A group of related records is a data file.
Database: It is an integrated collection of logically related
data elements.It consolidates the records previously stored
in separate files into a common pool of data elements that provides data for many applications.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 26/129
Types of Databases
1. Operational databases: Stores detailed data needed tosupport the business processes and operations of a
company. Ex: Inventory database, customer database,
human resource database etc.
2. Distributed databases: It involves replicating anddistributing copies or parts of databases to network servers
at a variety of sites. These databases can reside on network
servers on the world wide web, corporate intranets,
extranets or on other company networks.
Done to improve database performance at end user worksites.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 27/129
3. External databases: Access to a wealth of information
from external databases is available for a fee fromcommercial online services, with or without charge from
many sources on the world wide web.
Provides an endless variety of hyper linked pages of
multimedia documents for you to access.
4. Hypermedia databases: Stores information in a
hypermedia database consisting of hyperlinked pages of
multimedia (text, graphic, photographic images, video clips,
audio segments etc)
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 28/129
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 29/129
ZEROETH GENERATION
Man used his fingers, ropes, beads, bones,
pebbles and other objects for counting.
Abacus, Pascaline, Difference & Anyliticalengines
Electricity was not yet invented
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 30/129
FIRST GENERATION,
1947 ± 1956: The Vacuum Tube
y The first generation of computers, characterized byvacuum tubes, started in 1951 with the creation of -
UNIVAC (Universal Automatic Computer) ± a
tabulating machine which won the contest for thefastest machine which could count the US 1890 census.
VACUUM TUBES ± electronic tubes about the size of light bulbs.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 31/129
First Generation (1950¶s):
y The vacuum tubes were used in the circuits of these
computers.
y The input and output operations were done using punched
card technology.
y For external storage, magnetic tapes were used.
y The machine was capable to do one job at a time, therefore
batch processing was adopted.
y The language used by these computers was machine
language and assembly language.
y Example of Computers: UNIVAC, IBM 650 etc.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 32/129
DISADVANTAGES:
yThey generate more heat causing
many problems in temperature
regulation and climate control.
yTubes were subject to frequent burn-out.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 33/129
SECOND GENERATION,
1957 ± 1963: The TransistorThe year 1959 marked the invention of transistors, whichcharacterized the second generation of computers.
This invention of the transistor which was faster, smaller andrequired considerably less power to operate
TRANSISTOR ± was a three-legged component which shrunk thesize of the first generation computers. Occupied only 1/100th of thespace occupied by a vacuum tube
More reliable, had greater computational speed, required no warm-up time and consumed far less electricity.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 34/129
y Transistors were used in the circuits.
y The input operations were performed using punched cards and
magnetic tapes and for output operations, punched cards and papers were used.
y For external storage magnetic tapes were used.
y The orientation was towards multiple users i.e. the machinewas capable to process multiple tasks concurrently.
y The high level languages like FORTRAN, COBOL, BASICetc. were used as the languages by the computer.
y Example of Computers: IBM 1400 and 7000 series, GeneralElectric 635 etc.
Second Generation (1960¶s
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 35/129
THIRD GENERATION,
1964 ± 1979: The Integrated Circuit
Third generation computers arose in 1965 with the invention
of smaller electronic circuits called integrated circuits
(IC¶S)
INTEGRATED CIRCUITS ± are square silicon chipscontaining circuitry that can perform the functions of
hundreds of transistors.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 36/129
Third Generation (1970¶s):
y Integrated circuits replaced transistors. Inspite of their
y smaller size they were capable to perform better than
transistors.
y For data input and output operations monitors and
keyboards replaced the punched cards.
y For external storage magnetic disks were used.
y
Sophisticated operating systems, which were capable of handling several jobs concurrently were used.
y More advanced high level languages like PASCAL were used.
y Example of computers: IBM System
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 37/129
ADVANTAGES:
yRELIABILITY ± Unlike vacuum tubes,
silicon will not break down easily. It is
very seldom that you will have to replaceit.
yLOW COST ± Silicon chips are
relatively cheap because of their smallsize and availability in the market. It also
consumes less electricity.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 38/129
FOURTH GENERATION,
1980 ± present: The Microprocessor
y Marked by the use of microprocessor
y MICROPROCESSOR ± is a silicon chip that contains the
CPU ± part of the computer where all processing takes
place.4004 chip ± was the first microprocessor introduced by Intel
Corporation.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 39/129
Fourth Generation (1980¶s):y The circuits used VLSI and microprocessors of virtually microscopic
size, which led to drastic cut on the size of computer.
y The input output devices were the same monitors, keyboard, printer
etc.Micro computers have evolved.Magnetic disks were the primary devices used for external storage.The use of special software for maintaining large data bases became
popular.
y The application software for micro computer essentially became popular in this generation.
y Example of computers: IBM Systems
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 40/129
Fifth Generation (late 1990¶s):
y The computers of this generation use optic fibre
technology to handle Artificial Intelligence.
y These computers have capacity to think and reason which
can be used to solve problems where human intelligence isrequired.
y Expert Systems are examples of systems implementing
y Artificial Intelligence (AI).
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 41/129
yIs classified as fourth generationcomputers.
yFaster, more powerful, tremendous data
storage and processing capacityy New brands and models would come out
the market almost every other month.
yMany clones or imitations of the IBMhave become even more powerful and alot cheaper.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 42/129
yComputers became more affordable
y Computers an now be found in homes, schools, offices etc.
y There has been a tremendous improvement in softwaretechnology
y
Different software applications to choose from: word processing,spreadsheets, database management, games and entertainment.
y Computer subjects are now being offered not just to collegestudents but even to high school and elementary.
y Computers are now used as an aid in teaching math, science etc.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 43/129
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 44/129
Operating Systemy A program that controls the execution of application
programs
y
An interface between applications and hardware
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 45/129
Operating System Objectivesy Convenience
y Makes the computer more convenient to use
yEfficiencyy Allows computer system resources to be used in an efficient
manner
y Ability to evolve
y Permit effective development, testing, and introduction of new system functions without interfering with service
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 46/129
Layers of Computer System
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 47/129
Services Provided by the
Operating Systemy Program development
y Editors and debuggers
yProgram execution
y Access to I/O devices
y Controlled access to files
y System access
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 48/129
Services Provided by the
Operating Systemy Error detection and response
y Internal and external hardware errors
y
Memory error y Device failure
y Software errors
y Arithmetic overflow
y Access forbidden memory locations
y Operating system cannot grant request of application
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 49/129
Services Provided by the
Operating Systemy Accounting
y Collect usage statistics
y
Monitor performancey Used to anticipate future enhancements
y Used for billing purposes
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 50/129
Operating Systemy Responsible for managing resources
y Functions same way as ordinary computer software
y
It is program that is executedy Operating system relinquishes control of the processor
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 51/129
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 52/129
y Portion of operating system that is in main memory
y Contains most frequently used functions
yAlso called the nucleus
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 53/129
Evolution of an Operating Systemy Hardware upgrades plus new types of hardware
y New services
yFixes
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 54/129
Evolution of Operating
Systemsy Serial Processing
y No operating system
y
Machines run from a console with display lights, toggleswitches, input device, and printer
y Schedule time
y Setup included loading the compiler, source program, saving
compiled program, and loading and linking
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 55/129
Evolution of Operating
Systemsy Simple Batch Systems
y Monitors
y Software that controls the sequence of events
y Batch jobs together
y Program branches back to monitor when finished
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 56/129
Job Control Language (JCL)y Special type of programming language
y Provides instruction to the monitor
y
What compiler to usey What data to use
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 57/129
Hardware Featuresy Memory protection
y Do not allow the memory area containing the monitor to be
altered
y Timer
y Prevents a job from monopolizing the system
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 58/129
Hardware Featuresy Privileged instructions
y Certain machine level instructions can only be executed by
the monitor
y Interrupts
y Early computer models did not have this capability
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 59/129
Memory Protectiony User program executes in user mode
y Certain instructions may not be executed
y
Monitor executes in system modey Kernel mode
y Privileged instructions are executed
y Protected areas of memory may be accessed
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 60/129
I/O Devices Slow
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 61/129
Uniprogrammingy Processor must wait for I/O instruction to
complete before preceding
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 62/129
Multiprogrammingy When one job needs to wait for I/O, the
processor can switch to the other job
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 63/129
Multiprogramming
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 64/129
Utilization Histograms
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 65/129
Example
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 66/129
Time Sharingy Using multiprogramming to handle multiple interactive
jobs
y
Processor¶s time is shared among multiple usersy Multiple users simultaneously access the system through
terminals
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 67/129
Compatible Time-Sharing System
(CTSS)
y First time-sharing system developed at MIT
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 68/129
Major Achievementsy Processes
y Memory Management
yInformation protection and security
y Scheduling and resource management
y System structure
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 69/129
Processes
y A program in execution
y An instance of a program running on a computer
y The entity that can be assigned to and executed on a processor
y A unit of activity characterized by a single sequentialthread of execution, a current state, and an associated setof system resources
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 70/129
Process
y Consists of three components
y An executable program
y
Associated data needed by the programy Execution context of the program
y All information the operating system needs to manage the process
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 71/129
Process
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 72/129
Memory Managementy Process isolation
y Automatic allocation and management
y
Support of modular programmingy Protection and access control
y Long-term storage
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 73/129
Virtual Memory Addressing
I f ti P t ti d
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 74/129
Information Protection and
Securityy Availability
y Concerned with protecting the system against interruption
y
Confidentialityy Assuring that users cannot read data for which access is
unauthorized
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 75/129
Information Protection and Security
y Data integrity
y Protection of data from unauthorized modification
y
Authenticityy Concerned with the proper verification of the identity of
users and the validity of messages or data
Scheduling and Resource
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 76/129
Scheduling and Resource
Managementy Fairness
y Give equal and fair access to resources
y Differential responsiveness
y
Discriminate among different classes of jobsy Efficiency
y Maximize throughput, minimize response time, and
accommodate as many uses as possible
Key Elements of
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 77/129
K ey Elements of
Operating System
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 78/129
System Structurey View the system as a series of levels
y Each level performs a related subset of functions
y
Each level relies on the next lower level to perform more primitive functions
y This decomposes a problem into a number of more
manageable subproblems
Multiprogramming and
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 79/129
Multiprogramming and
Multiprocessing
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 80/129
Modern Operating Systemsy Distributed operating systems
y Provides the illusion of a single main memory space and
single secondary memory space
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 81/129
Modern Operating Systems
y Object-oriented design
y Used for adding modular extensions to a small kernel
y Enables programmers to customize an operating system
without disrupting system integrity
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 82/129
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 83/129
Operating System Organizationy Modified microkernel architecture
y Not a pure microkernel
y Many system functions outside of the microkernel run in
kernel mode
y Any module can be removed, upgraded, or replaced
without rewriting the entire system
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 84/129
Windows Executivey I/O manager
y Cache manager
y Object manager
y Plug and play manager
y Power manager
y Security reference monitor
y Virtual memory manager
y Process/thread manager
y Configuration manager
y Local procedure call (LPC) facility
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 85/129
UNIX
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 86/129
UNIX K ernel
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 87/129
Modern UNIX K ernel
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 88/129
Modern UNIX Systemsy System V Release 4 (SVR4)
y Solaris 9
y
4.4BSDy Linux
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 89/129
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 90/129
Generation of Languagesy First Generation Languages
y Machine Language: consists of group of binary code, or
bytes that represents every thing from characters,
arithmetic & logic operations to store locations in RAM &
CPU
y Second Generation Languages
y
Assembler Languages:
to save programming time, thelong strings of 0¶s & 1¶s that represents each command,
were represent by , or assembled into, a single three or
four letters instructions.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 91/129
y Third Generation Languages
y High Level Languages: user instructions which are called
statements translating HLL into Machine languages
program called ³Compiler´ or ³interpreters´
y Easy to learn & program than the assembler
y E.g., FORTRAN ± FOR mula TRANslator
y COBOL ± COmmon Business Oriented Language
y BASIC ± Beginners All purpose Symbolic Instruction Code
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 92/129
y Fourth Generation Languages : Application program
develop more easier connected to DBMS. Many routine
procedures are programmed & can be incorporated into a
program with single procedure.
y Command more in English.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 93/129
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 94/129
Telecommunicationsy Tele (Far) + Communications
y Early telecommunications
y smoke signals and drums
y visual telegraphy (or semaphore in 1792)
y Telegraph and telephone
y Telegraph (1839)
y Telephone (1876)
y Radio and television
y Telephony
y Voice and Data
Communications and
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 95/129
Networksy Data Communications
y Transmission of signals
y Encoding, interfacing, signal integrity, multiplexing etc.
y Networking
y Topology & architecture used to interconnect devices
y Networks of communication systems
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 96/129
Network Trends (1980-Present)
Microcontroller Networking
Wireless
Voice, Image, Data, Video
Integrated Systems!
Microcontroller
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 97/129
Communication Systemsy Process describing transfer of information, data, instructions betweenone or more systems through some media
y Examplesy people, computers, cell phones, etc.
y Computer communication systems
y Signals passing through the communication channel can be Digital, or analog
y Analog signals: continuous electrical waves
y Digital signals: individual electrical pulses (bits)
y Receivers and transmitters: desktop computers, mainframe computers,
etc.
TX
RX
RX
RX
Communication channel
Communication
media
Amp/Adaptor
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 98/129
Communication Systems
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 99/129
Communications Componentsy Basic components of a
communication system
y Communication technologies
y Communication devices
y Communication channels
y Communication software
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 100/129
A Communications Model
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 101/129
Communications Tasks
Transmission system utilization Addressing
Interfacing Routing
Signal generation Recovery
Synchronization Message formatting
Exchange management Security
Error detection and correction Network management
Flow control
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 102/129
Data Communications Model
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 103/129
Communication Technology Applications
voice mail Twitt
er
e-
instant
messagingchat rooms
newsgroup
s
telephony videoconferencing
collaboration groupware global positioning
system (GPS)
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 104/129
Communication Technologies -
Applicationsy Different technologies allowing us to communicate
y Examples: Voice mail, fax, email, instant message, chat rooms,news groups, telephony, GPS, and more
y Voice mail: Similar to answering machine but digitized
y Fax: Sending hardcopy of text or photographs between computers usingfax modem
y Email: electronic mail ± sending text, files, images between differentcomputer networks - must have email software
y More than 1.3 billion people send 244 billion messages monthly!
y Chat rooms: Allows communications in real time when connected tothe Internet
y
Telephony: Talking to other people over the Internet (also called VoIP)y Sends digitized audio signals over the Internet
y Requires Internet telephone software
y Groupware: Software application allowing a group of people tocommunicate with each other (exchange data)
y Address book, appointment book, schedules, etc.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 105/129
Communication Devicesy Any type of hardware capable of transmitting data, instructions, and
information between devices
y Functioning as receiver, transmitter, adaptor, converter
y Basic characteristics: How fast, how far, how much data!
y Examples: Dial-up modems, ISDN[Integrated service Digital Network], DSLmodems, network interface cards
y Dial-up modem: uses standard phone linesy Converts digital information into analog
y Consists of a modulator and a demodulator
y Can be external, internal, wireless
y Cable modem: a modem that transmits and receives data over the cabletelevision (CATV) network
y Also called broadband modem (carrying multiple signals)y The incoming signal is split
y Requires a cable modem
y Network interface cards: Adaptor cards residing in the computer totransmit and receiver data over the network (NIC)
y Operate with different network technologies (e.g., Ethernet)
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 106/129
Communication Channelsy A channel is a path between two communication devices
y Channel capacity: How much data can be passed through
the channel (bit/sec)
y Also called channel bandwidth
y The smaller the pipe the slower data transfer!
y Consists of one or more transmission media
y Materials carrying the signal
y Two types:
y Physical: wire cable
y Wireless: Air destination
network
server
T1
lines
T1
lines
T1
lines
T3
lines
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 107/129
Physical Transmission Mediay A tangible media
y Examples: Twisted-pair cable, coaxial cable, Fiber-optics, etc.
y Twisted-pair cable:
y One or more twisted wires bundled together (why?)
y Made of copper y Coax-Cable:
y Consists of single copper wire surrounded by three layers of insulatingand metal materials
y Typically used for cable TV
y Fiber-optics:
y Strands of glass or plastic used to transmit lighty Very high capacity, low noise, small size, less suitable to natural
disturbances
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 108/129
Physical Transmission Media
plastic outer
coating
woven or
braided metal
insulating
material
copper wire
twisted-pair cable twisted-pair wire
protective
coating
glass cladding
optical fiber
core
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 109/129
Wireless Transmission Mediay Broadcast Radio
y Distribute signals through the air over long distance
y Uses an antenna
y
Typically for stationary locationsy Can be short range
y Cellular Radio
y A form of broadcast radio used for mobile communication
y
High frequency radio waves to transmitvoice or data
y Utilizes frequency-reuse
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 110/129
Wireless Transmission Mediay Microwaves
y Radio waves providing high speedtransmission
y They are point-to-point (can¶t be obstructed)
y Used for satellite communication
y Infrared (IR)y Wireless transmission media that sends signals
using infrared light- waves - Such as?
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 111/129
Physical Transmission Media
100 Mbps is how many bits per
sec?
Which is bigger:
10,000 Mbps, 0.01Tbps or
Wireless channel
capacity:
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 112/129
Networksy Collection of computers and devices connected together
y Used to transfer information or files, share resources, etc.
y What is the largest network?
y Characterized based on their geographical coverage, speed, capacities
y Networks are categorized based on the following characteristics:
y Network coverage: LAN, MAN, WAN
y Network topologies: how the computers are connected together
y Network technologies
y Network architecture
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 113/129
Network coveragey
Local Area Networks: y Used for small networks (school, home, office)
y Examples and configurations:
y Wireless LAN or Switched LAN
y Peer-2-PEER : connecting several computers together (<10)
y Client/Server : The serves shares its resources between
different clientsy Metropolitan Area Network
y Backbone network connecting all LANs
y Can cover a city or the entire country
y Wide Area Network
y
Typically between cities and countriesy Technology:
y Circuit Switch, Packet Switch, Frame Relay, ATM
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 114/129
LAN v.s WANLAN - Local Area Network a group of
computers connected within a building or a
campus (Example of LAN may consist of
computers located on a single floor or a
building or it might link all the computers in a
small company.
WAN - A network consisting of
computers of LAN's connected
across a distance WAN can cover
small to large distances, usingdifferent topologies such as telephone
lines, fiber optic cabling, satellite
transmissions and microwave
transmissions.
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 115/129
Network Topologiesy Configuration or physical arrangement in which devices are connected
together
y BUS networks: Single central cable connected a number of devices
y Easy and cheap
y
Popular for LANsy RING networks: a number of computers are connected on a closed loop
y Covers large distances
y Primarily used for LANs and WANs
y STAR networks: connecting all devices to a central unit
y All computers are connected to a central device called hub
y All data must pass through the huby What is the problem with this?
y Susceptible to failure
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 116/129
Network Topologiespersonal
computer
personal
computer
personal
computer
personal
computer
personal
computer
host
computer
printer
file server
personal computer
personal computer
personal computer
personal computer
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 117/129
Network Architecturey Refers to how the computer or devices are designed in a network
y Basic types:
y Centralized ± using mainframesy Peer-2-Peer :
y Each computer (peer) has equal responsibilities, capacities, sharing hardware, data,with the other computers on the peer-to-peer network
y
Good for small businesses and home networksy Simple and inexpensive
y Client/Server :
y All clients must request service from the server
y The server is also called a ho st
y Different servers perform different tasks: F ile server , network server , etc.
clien
t
clien
t
clien
t
serv
er
laser
printer
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 118/129
(Data) Network Technologiesy Vary depending on the type of devices we use for
interconnecting computers and devices together
y Ethernet:y LAN technology allowing computers to access the network
y Susceptible to collision
y Can be based on BUS or STAR topologies
y Physical layer y Gigabit Ethernet using optical fiber, twisted pair cable, or
balanced copper cable
Project
Topic
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 119/129
Network Examplesy Interplanetary (Internet) Network
http://www.ece.gatech.edu/research/labs/ bwn/deepspace/
Project
Topic
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 120/129
Network Example:
Optical Networksy Fiber-to-the-x
y Broadband network architecture thatuses optical fiber to replace copper
y Used for last mile telecommunications
y Fiber Distribution Network (reaching
different customers)
Project
Topic
Network Example:
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 121/129
Network Example:Telephone Networks
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 122/129
Network ExamplesPublic Telephone
Network
T-Carrier Dedicated
Lines
Dail-up
DSL ISDN
ATM
What about Cable Internet Services?
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 123/129
Cellular Network Examplesy 0G
y Single, powerful base station covering a wide area, and eachtelephone would effectively monopolize a channel over thatwhole area while in use (developed in 40¶s)
y No frequency use or handoff (basis of modern cell phonetechnology)
y 1Gy Fully automatic cellular networks
y introduced in the early to mid 1980s
y2Gy Introduced in 1991 in Finland on the GSM standard
y Offered the first data service with person-to-person SMS textmessaging
C ll l N k E l
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 124/129
Cellular Network Examplesy 3G:
y Faster than PCS; Used for multimedia andgraphics
y Compared to 2G and 2.5G services, 3G allowssimultaneous use of speech and data services andhigher data rates (up to 14.4 Mbit/s on the
downlink and 5.8 Mbit/s.y 4G:
y Fourth generation of cellular wireless;
y providing a comprehensive and secure IP basedservice to users "Anytime, Anywhere" at highdata rates
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 125/129
Wireless Technologies [WAP]y The Wireless Application protocol [WAP] is a set of
specifications, developed by WAP forum that lets
developers using wireless mark up language[WMP] built
network applications designed for handled wirelessdevices.
y Wire-free World: (Blue Tooth)
Is a computing, networking and telecommunications
industry specification that enables mobile phones,
Computers and other WIDs to talk each other using radio
waves.
Wireless internet as the way
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 126/129
Wireless internet as the way
of the Futurey 1. Blue tooth is a global defacto standard for wireless connectivity.
Based on low cost short range radio link. Blue tooth cuts that cards
that used to tie up digital devices.
y 2. UMTS (Universal Mobile Telecommunication System) is also calle
third generation broadband, pocket based transmission of text,
digitised voice, video and multimedia.
y 3. GPRS (General Pocket Radio Services) is packet based wireless
communication service that promises data transmission and continuou
connection to the internet for mobile phone and computer user.y 4. i mode is wireless technology developed by Japanese Company
NTT DoCoMo that enables users to access internet services via their
cellular phones.
Internet, Intranet and
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 127/129
Internet, Intranet and
ExtranetIntranet Extranet
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 128/129
Internet
5/12/2018 Computer Fundamentals module 3 - slidepdf.com
http://slidepdf.com/reader/full/computer-fundamentals-module-3 129/129
Electronic Market1. Broker Model :
y Attractive packaging
y Efficient delivery
y Accurate payment handling
2. Customization model :
selling of customized products to mass market
3. Contact Model :
Matching prospective supplier of goods and services with
buyers.