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EDP (Electronic Data Processing)
DOS / GW Basic
Basics of Computer Networking
Software Applications
1
Computer Application Course
2
Bits & Bytes Bit:
A computer is an electronic machine like a simple light bulb Circuits in a computer have two states: on and off. "On" is represented by the number 1, and "off" is represented by "0". Computer stores information in its memory only in 1's and 0's. Each one or zero is called a bit. It's the smallest unit of information.
Byte (Eight Bits): Bit can only be a zero or a one Computer Engrs decided to group 8 bits together to represent letter. There are 256 different combinations you can make with 8 1's and
0's. It's enough to cover the alphabet and other special characters. These 8 bits grouped together are called a byte.
Digital Data
3
4
American Standard Code for Information Interchange (ASCII)
"A" is stored on computer as 1000 0010
"&" is stored on computer as 0110 0100 "SUPARCO" would look like:
11001010 10101010 00001010 10000010 01001010 11000010 11110010
This sequence of numbers comprises seven letters, so it takes 7 bytes.
a text file containing " Pakistan Space & Upper Atmosphere Research Commission", will take 53 bytes.
Byte can hold a very small piece of information.
We often think in terms of kilobytes, megabytes, and gigabytes.
5
American Standard Code for Information Interchange (ASCII)
Used to represent English characters on Computers
6
Kilo, Mega, Giga, Tera Byte
kilobyt(KB)
Normally defined as 1,000 bytes.
Exactly, kilobyte is 1,024 bytes.
An average word-processing document consumes about 100 kilobytes.
The average web page on the Internet is about 40 kilobytes.
A megabyte (MB)
Normally defined as 1,000 kilobytes or 1,000,000 bytes.
Exactly, 1 Megabyte = 1,024 kilobytes or 1,048,576 bytes.
7
Units of Data Measurement
8
Data Concepts
Data: Collection of raw facts or unprocessed information.
Field: Data Item or Unit of Information. (R.No., Name, Address)
Record: Group of interrelated Fields or information item.
File: One or more records or group of records (Table, Sheet, doc)
Data base: Group of interrelated files.
Character: Each character takes one Byte (a,b,$,@,5)
Byte: Group of bits that represents a character.
Bit: Smallest unit of information that takes only 2 values 0 or 1.
Summary
9
History of Computers
Abacus; counting machine
Used in China about 2500 years ago
Mechanical calculating Machine (1642)
By French Mathematician, Blais Pascal
Use of gears and levers
Difference Analytical Engine (1822)
By Charles Babbage
Algebraic expressions
Need of simple decisions making machine
10
History of Computers
1st computer like machine - Mark I
Developed by IBM & Harvard University
Used mechanical telephone relays
Processed data on punch cards
Could not make decisions
11
History of Computers
1st electronic computers built during 2nd World War
Known as First Generation Computers
Germans designed the Z3 and Z4
Destroyed during Allied bombing of Germany
Used binary operations & keyboard for input
British built the Colossus
Used for code-breaking (1943 to 1945)
Americans built computers to calculate firing tables
The ENIAC (Electronic Numerical Integrator & Calculator)
Could do 5000 additions or 350 multiplications in a Sec
ENIAC - beginning of 1st Generation Computers
12
First Generation Machines (Vacuum Tubes)
Computers without moving parts
Based on the flow of electricity
Resistors & vacuum tubes
Switches and relays replaced by electronic circuits
Vast improvement over the mechanical machines
Contained over 17,000 tubes
Same tubes used in radios at that time
13
Second Generation (Transistors)
Transistor made smaller & Cheap computers (1948)
Computers shrank in size
Still huge by today’s standards
Transistors are made of semiconductors
Smaller, faster, more reliable and cheaper
Growth of computer industry in the world
14
Third Generation (Integrated Circuits)
Integrated circuits, or IC (1970s)
IC - single component containing many transistors
Smaller, cheaper and more reliable
Complex Electronics, Large Storage, higher speed
1st IC computer sold in 1964
Computer prices came down, sale went up
15
Fourth Generation (microprocessor)
Central processing unit
The Brain of the computer on a single chip
Chip called microprocessor
Present computers
Story does not end here
Fifth generation computer are already in the air
Intelligence will be greatly improve
Approach of a human being
Documentary
16
Basic Computer Concepts
Computer: Programmable electronic device that can Store, Retrieve, and Process data
Computer
• Makes Calculations accurate & fast• Cannot Think • Makes decisions based on comparisons • Is simply a machine • Cannot solve problems on its own• Follows Instructions
Documentary
17
How Computer handles the task
Input
Store
Process
Output
18
Parts of the Computer
Input Devices
Storage Devices
CPU
Output Devices
19
Types of Computer
1. Digital Computer Very fast, consume less power
a) General purpose: Variety of functions
b) Special purpose: For specific task
2. Analog Computer
Made of Mechanical & Electronic parts
Continuous physical data (temp, pressure, distance, Volt)
3. Hybrid Computer
Features of both analog and digital
For specific applications & industrial control processes
Also used in missiles, spaceships & military weapons
20
Classification of Computers 1. Mainframe Computers
Very large, entire room
Store enormous information
Perform many tasks at a time
Communicate many users at a time
Very expensive
Many terminals
Multi processors
lots of disk space / storage
Hundreds of simultaneous users
Time sharing system
21
Classification of Computers
2. Mini Computers
Smaller than mainframes
less expensive
Most features of mainframes
On a limited scale
Less terminals
For Medium and small businesses
22
Classification of Computers
3. Micro Computers
Computers at SITT
Desktop, Laptop, Palmtop models
limited resources
Single user
Slower
Good for small businesses, homes, and school classrooms.
Inexpensive
Easy to use
Essential part of modern life
23
Classification of Computers
4. Super Computers
Used for the heavy stuff Weather maps Construction of atom bombs Finding oil Earthquake prediction Sciences where a lot of calculations Spy purposes
Several Parallel processors Fastest computers Real time operations Very expensive
Video
24
Central Processing Unit (CPU)
25
CPU Functions Take instructions & tell the computer system what to do Performs arithmetic/logical calculations and data manipulation Holds data and instructions which are in current use
26
Control Unit (CU)
Directs entire computer sys to carry out stored program instructions Communicate with ALU and MU Coordinates the activities of other two units Coordinates the activities of linked peripheral & storage devices Instructs ALU operations to be performed It is literally in control
27
Arithmetic Logic Unit (ALU)
Executes arithmetic and logical operations Arithmetic operations include +, -, * and / Logical operations compare nos, letters and special characters Comparison operations test for three conditions:
• = condition, when two values are the same • < condition, when one value is smaller than the other • > condition, when one value is larger than the other
ALU also performs logic functions such as AND, OR and NOT
28
Memory Unit
Part of the computer that holds data & instructions for processing
Closely associated with the CPU, separate from it Primary storage, primary memory, main storage, internal
storage & main memory Software from a floppy disk, hard disk or CD-ROM, is loaded
in MU
29
RAM
Random Access Memory
Programs are temporary stored
Temporary Memory
Computers active memory
Faster memory
CPU fetch instructions from RAM to run a Program
Results of calculations are stored in RAM
More RAM in your PC, larger programs you can run
Volatile - Erased when power off
30
ROM
Read Only Memory
Permanent Memory
CPU can only read instructions from ROM
Comes with instructions permanently stored by manufacturer
Instructions cannot be over-written
Special instructions needed for start up
POST (Power on Self Test)
last instruction directs the computer to load OS
Non-volatile – Does not erase on power off
31
PROM & EPROM
PROM Stands for Programmable Read Only Memory
Can be programmed by prom-programmer
Once programmable
Non-volatile
EPROM Stands for Erasable Programmable Read Only Memory
Re-programmable using prom-programmer
Erased by exposure to ultraviolet light
Non-volatile
32
How the CPU works
Centrally located on the motherboard
Carries large share of the work in the computer
Data pass continually through it
Data come from the RAM and the units (keyboard, drives, etc.)
After processing, the data is sent back to RAM and the units
Continually receives instructions to be executed
Each instruction is a data processing
Mostly calculations and data transport
33
Instruction-Execution Cycle
CU gets the instruction from memory
CU decides what the instruction means and directs the necessary data to be moved from the memory to ALU
ALU performs the actual operation on the data
Result is stored in memory or a register
Instr
ucti
on
Tim
eExecu
tion
Tim
e
Mach
ine C
ycle
Video
34
Coprocessor
Most microcomputers are equipped with an optional coprocessor
Special microchip designed to perform one or more specific tasks
Most common - Math coprocessor
Greatly speeds up numerical calculations
Used for floating point calculations
35
CPU Generations
Video
36
Architecture
37
Architecture
Modern microcomputers use a motherboard
Circuit board containing CPU, ROM, RAM, & other circuitry
Electronically linked thru a series of parallel lines - System Bus
System bus carries three types of information
Control: Control lines - Control bus
Address: Address lines - Address bus
Data: data lines - Data bus
Width of bus is important to the overall performance
The wider the bus, the more information can be carried at a time
Most Computers support 8-bit, 16-bit, 32-bit, 64-bit buses
38
Architecture
Expansion slots provide access to the system bus I/O device connected to computer through one of these slots An appropriate interface circuit board is used RAM Slots - used to expand the RAM
I/O Interface
I/O communications take place through an interface card Interface cards are designed to convert the data form Possible speed differences b/w processor and devices Interface card corresponds with control units
Video
39
Power Supply Converts normal power supply for computer use
220 V or 110 V AC to 12 V and 5 V DC
Motherboard Main circuit board of a computer
All electrical components plug into the motherboard
Expansion Slot For additional Interface Cards Additional features and functions
Inside Computer Casing
40
Interface Card Adds new features to a computer
Random Access Memory (RAM) Temporarily stores information inside a computer
Central Processing Unit (CPU) Main chip in a computer that:
• Processes instructions • Performs calculations • Manages information flow
Inside Computer Casing
41
Hard Drive Device used to store information Permanent Storage
CD-ROM Reads information stored in compact discs (CDs).
Floppy Drive Stores and retrieves information on floppy disks
Inside Computer Casing
Video
42
Connector at the back to plug an external device Allows instructions & data to flow between Computer &
device
Keyboard Port & Mouse Port
Serial Port9 or 25 pins, Male connector Connects mouse or modem Named COM1, COM2, and so on.
Parallel Port25 holes, female connectorConnects a printer or tape driveNamed LPT
Computer Ports
43
USB Port
Universal Serial Bus Very fast as compared to Serial & Parallel PortsNew type of port that connect multiple devices
Network PortOn Network Interface Card To connect the computer with a network
Monitor PortOn VGA Card
To connect a monitor
Computer Ports
44
Modem ConnectionsUsed to connect computers via Telephone Line Phone: To connect Telephone set Line: To Connect Telephone Line Spk: To connect speakers or headphones Mic In: To connect a microphone
Sound Card ConnectionsGame port: For joystick Line In: To connect a cassette or CD playerLine Out: To connect an amplifier Spk: To connect speakers or headphones Mic In: To connect a microphone
Computer Ports
Dell Tour
45
Input Devices
Key BoardTo Enter information and instructions into a computer
46
Mouse
Mouse ActionsClick: For SelectionRight-Click: list of commands Drag and Drop: Double-Click: Opens a document or starts a
program
Mouse Pad: Provides a smooth surface Clean Mouse: Clean ball & Rollers for smooth
motion Cordless Mouse: Runs on battery & reduces the
mess
Other Pointing Devices a) Joystick: Control movement of objects on
screenb) Touchpad: Sensitive to pressure and motionc) Trackball: Upside-down mouse
To move pointer on screen
47
Scanner Reads graphics and text
into a computer
Scan Text: Uses Optical Characters Recognition (OCR) software Scan Images: Photographs, drawings and logos
Types of Scannersa) Handheld Scannerb) Flatbed Scannerc) Sheet-Fed Scanner
Color Depth: Indicates number of colors scanner can detect Scanning Mode: a) Line Art: Black and whiteb) Grayscale Scanner: Black, white and shades of gray c) Color Scanner: Shades of red, blue and greenResolution• Amount of details the scanner can detect • Measured in dots per inch (dpi) • Range from 600 dpi to 2400 dpi
48
Digital Camera Take photos that can be used on computer
Work with Photos: • Transfer photos from a digital camera to a computer. • Use in documents, e-mail messages.
Features: • Liquid Crystal Display (LCD) screen to view shots• Built-in flash • Zoom lens • Record short videos.
Megapixels: • Resolution, is measured in megapixels • One megapixel = 1000 x 1000 pixels • Currently 1, 2 and 3-megapixel cameras available
Memory: Store photos in memory until transferred to computer
a) Removable: Memory cards or regular floppy diskb) Built-in: Must transfer the photos to computer when full
49
Digital Video CameraRecords video in a format that can be saved on a computer
Resolution:• Charged Coupling Device (CCD) to capture video
• Video quality depends on the amount of detail the CCD can detect
• Resolution, is measured in pixels.
• Higher the resolution, the cleaner the video
• Resolution between 250,000 and 700,000 pixels
Video Editing Software: • To edit videos saved on your computer
• Movie Maker
50
Web Camera Allows to send live video over the Internet
Resolution & Speed:• Determine the quality of the images it can produce
• Higher resolution produce clearer / detailed video
• Slow speed can cause a video to appear choppy
• 15 frames per second at a resolution of 640 x 480 pixels
• 30 frames per second at a resolution of 352 x 288 pixels
Video Conferencing: • Often used for videoconferencing
• Face-to-face conversations with people on the Internet or NW
• PC must have a sound card, speakers and a microphone
51
Monitor & Video Card
Monitor: Displays text & images generated by the video card
Screen: Display area of a monitor
Video Card: Translates instructions from the computer to a form the monitor can understand
Size: Measured diagonally across the screen
Flat-panel Monitors:
Controls: To adjust brightness, contrast and other features
work together to display text and images on the screen
Output Devices
52
Monitor & Video Card Dot Pitch: • Distance between tiny dots on a screen• Determines the sharpness of images • Smaller dot pitch provides crisper images• Select Dot pitch of 0.28 mm or less.
Refresh Rate: • Speed of monitor to redraws or update images • Higher the refresh rate, the less flicker on the
screen• Reduce eye strain • Measured in hertz (Hz) • Refresh rate of 72 Hz or more is recommended
Electromagnetic Radiation
53
Monitor & Video Card Glare Filter: Reduce eye strain
Screen Saver:
Video Card MemoryA video card has memory chips that Temporarily store information before sending to
monitor
AGP: (Accelerated Graphics Port) video card Uses AGP bus to communicate directly with main
memory Quick display of complex images on your monitor Specially designed to displaying 3D images
3D Graphics Accelerator Card: Has a special chip, Graphics Processing Unit (GPU) Produce 3D graphicsAllows to display information without using CPU
54
Monitor & Video Card Resolution• Amount of information a monitor can display, Horizontal x vertical
pixels 640 x 480, 800 x 600, 1024 x 768, 1280 x 1024, 1600 x
1280
Color Depth• 16 Colors (4-bit color), Choppy-looking images
• 256 Colors (8-bit color), Suitable for most home, business and game applications
• 65,536 Colors (16-bit color) Useful for video and desktop publishing applications
• 16,777,216 Colors (24-bit color), Useful for photographic work
• 4,294,967,296 Colors (32-bit color), Useful for graphics intensive games
55
Printers
• Connected via a port at the back of the PC
• Connected to serial or, more commonly, parallel port
• Or with USB ports in recent computers
• Serial interfaces are considerably slower
• Very Important for applications such as word processing
• Vary a lot in quality and speed of output
• Printers can be grouped by the method with which they print
Produces a paper copy of the information displayed on the screen
56
Dot-Matrix Printers
• Most common and low cost
• Set of pins impacting on paper through ribbon
• Quality depends on the no. of pins on the printer head
• 9 pins – low quality
• 24 pin – better quality
• Most dot-matrix printers have NLQ (Near Letter Quality)
• Common dot-matrix printers are Epson and Panasonic
Video
57
Daisywheel Printers
• First printers to produce letter quality (LQ) output
• Operation similar to typewriters
• limited by the fact that they can only produce characters
• Cannot produce graphical output, only text
• Virtually obsolete due to wide availability of cheap laser & inkjet printers
58
Laser Printers
• High-speed printer • Ideal for business, personal docs & professional graphics work • Works like a photocopier• Produce letter quality text & high quality graphics • Expensive to buy and run but costs are coming down • Quality measured in dots per inch (dpi) • Ranges from 600 to 2400 dots per inch (dpi) • Page printers• Speed measured in pages per minute (ppm) • 4 to 16 pages per minute (ppm) • Use a fine powdered ink, called toner, which comes in a cartridge • Color laser printer more expensive• Have a Central Processing Unit (CPU) • CPU Process instructions & manages information flow• Store pages in built-in memory before printing • Hewlett Packard Laserjet series common standard
Video
59
Inkjet Printers
• Produces high-quality docs at a relatively low price
• Ideal for routine business & personal docs
• Spraying a fine jet of ink on paper to form characters & graphic
• Produce high quality output, near to laser quality
• Speed of 0.5 to 4 pages per minute (ppm)
• Resolution, or quality, of the images ranges from 180 to 720 (dpi)
• Use ink stored in cartridges
• When the ink runs out, you replace the cartridge
• Color ink jet printers are very popular because of low cost
• Sprays cyan, magenta, yellow and black ink to create different colors
• Most popular - Hewlett Packard DeskJet
Video
60
Multifunction Printers
• Can perform more than one task
• Often able to work as:Fax machine Scanner Photocopier Printer
• Color multifunction printers are also available
61
Print Buffer and Spooler
• Computer can send data faster than a printer can accept• Print spooler or print buffer acts like a water tank • Holds data and then releasing it at a speed the printer can
handle
Print Spooler: • Can store more information than a print buffer • lets continue using computer without waiting for a doc to finish
printing• Windows comes with a built-in print spooler
Print Buffer: • Section of memory in a printer • Stores the information selected for printing • When the buffer is full, computer must wait before sending
more data
62
Plotters
• Essential for graphical applications like Computer Aided Design (CAD)
• Provide a better quality graphics output than printers
• Allow the use of different colours
• Application package will translate graphic into plotter instructions
• Hewlett Packard Graphic Language (HPGL)
• Can be interfaced to a PC by a parallel or serial port
• Serial connection is more common than for printers
• Come in various configurations, varying in number of pens available
• usually 4 or 8 pens, one for each colour
• Sizes A4 , A3
• Common manufacturers - Hewlett Packard and Roland.
Video
63
Floppy Disks Drives
Secondary Storage Devices
• Drives for each capacities • XT PCs used double density drives • Present PCs use high density disk drives • Disk drives are referenced by drive letter
• Used for data transfer from PC to PC• Made of flexible plastic • Magnetically records information • Has to be formatted for use • It writes tracks & sectors on surface • Double sided floppies available
64
Hard Disks
• Used to store information• Magnetically stores data on rotating disks • Has several read/write heads
Capacity • Amount of information a HDD can store• Measured in Giga bytes• Purchase the largest you can afford • New programs and data will quickly fill a hard drive
Partitioning a Hard Disk • Splitting HDD into different logical drives• 80Gb hard disk into four 20Gb logical disks• Can be treated as four separate drives, C, D, E & F • Way of splitting disk into more manageable sizes
65
Hard Disks
Average Access Time • Speed at which a hard drive finds data • Measured in milliseconds (ms) • Most HDDs have an access time of 9 to 14 ms • Lower access time, faster the hard drive
Defragment a Drive • HDD stores parts of a file in many different locations • To retrieve a file, computer search many areas of the drive• To increase the speed, use Defragment utility Repair a Drive • Periodically use disk repair programs to improve the
performance• Check HDD for errors at least once a month
66
Create More Disk Space
Archive Information • Store old or rarely used files on tape or CD • Remove files from HDD for more space • Delete all files and programs no longer in use
Data Compression • Files stored on HDD can be compressed, or squeezed • This doubles the capacity of drive
Protect a Hard Drive• Virus: Replicates itself by attaching to files• Spreads by: Floppies and Modem• Use Anti virus programs • Back Up Data Video
67
Removable Storage Devices
Jaz Drive: • Very fast • large capacity in removable storage devices • Can store up to 2 GB of data on a disk
Zip Drive: • Relatively inexpensive • Can store up to 250 MB of data on a disk
LS-120 Drive: • Can store up to 120 MB of data on a disk • Also accept regular floppy disks
Thumb Drive: • For Personal security and privacy • Directly plugged into the USB port • Fingerprint sensor verifies the user
68
CD-ROM
CD-ROM Disc• Same type of disc at a music store • Can store about 650 MB of data • Equal to an entire set of encylopedias or over 400
floppy disks• Large capacity gives room for images, animation and
video
CD-ROM Drive Speed• Determines how fast a disc spins • Also called the data transfer rate or throughput • Very important when viewing video and animation
CD-ROM Applications• Install Programs • Play Multimedia • Play Music & Video CDs
Reads info stored on CDs
69
CD-ROM
CD-R and CD-RW Drives• Used to store information on CDs • Can play CD-ROM discs & music CDs
CD-R Drive: (Compact Disc Recordable)• Permanently stores data on a CD-R disc • Not erasable • Data cannot be changed• Once Recordable
CD-RW Drive: (Compact Disc ReWritable)• Record data on CD-RW discs • Data can be change on a CD-RW • Can also play & record data on CD-R discs• Multiple recording Video
70
DVD-ROM Drive (Digital Versatile Disc)
• Reads information stored on DVD-ROM discs • Similar in size and shape to a CD-ROM disc • Can store a lot more information
DVD-Video: • Can play DVD-Video discs• Holds full-length, full-screen movies • Much better quality than video cassettes & CDs
Multimedia: • Can play multimedia DVD-ROM discs, CD-ROM discs &
music CDs • Can also play CD-R and CD-RW discs
Disc Storage Capacity: • Can store at least 4.7 GB of data • Equals about seven CD-ROM discs • Can be single-sided or double-sided
71
Tape Drive
• Copies files from computer to tape cartridges • Also called tape backup units • External & Internal Tape drives • External tape drive is more expensive
Tape Cartridges• Stores huge quantity of information• Similar to the music cassettes • Store in a cool & dry place • Keep away from electrical equipment
Tape Drive Applications• Transfer Data • Back Up Data• Archive Data
72
Computer
Hardware Software
Input Devices
Output Devices
Storage Devices
Process Devices
System Software Application Soft
Operating System
System Support
General Purpose
Application Specific
Custom Built
CLI
GUI
73
Word Processing
Creating & saving a document
Formatting a document
Editing: Undo, cut, copy, paste, select all, find & replace
Helping tools: Spelling & grammar checker, synonyms
Output: Print options, fax, e-mail, saving as Web page
Merging Document: Mail-merge with database
Insertion: Table, Images, Hyperlinks, Animation & Sound
To create, edit, revise, and format documents for output
74
Desktop Publishers
Create text frames using a word processing or desktop publisher
Prepare non-text segments; images, boarder, table, photos, etc,
Arrange document pages; layout texts and non-texts segments
Insert the texts segments into frames
Insert non-text segments into frames
Refine the lay outs; resize segments, fine-tune the layout,
Publish it
To create document with complicated layouts
75
Presentation Software
Decide template
Create presentation outline
Compile and create non-text materials, graph, images
Integrate resources
Add special effects
Add notes for each slide
To create transparencies, slides, handouts, and web pages for presentation
76
Spreadsheet Software
Organizes data into rows & columns
Range of cells
Cell data type
Data Entry
Use of Functions or Formulas
Copy and paste of formulas to desired column or row
Graph of data
Insertion
Output: Print options, fax, e-mail
To create, edit, revise, perform computation on rows and columns of tables, and to format a worksheet for output
77
Database Software
Create, maintain and update database
Select specific data based on certain logical criteria
Make inquiries for specific data (query)
Design of data entry Form
Design of Reports
Sorting data based on specific field
Import and export data
Allows the users to enter, organize, arrange and rearrange, assemble, select, manipulate stored data