EDP (Electronic Data Processing)

DOS / GW Basic

Basics of Computer Networking

Software Applications

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Computer Application Course

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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

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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.

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American Standard Code for Information Interchange (ASCII)

Used to represent English characters on Computers

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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.

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Units of Data Measurement

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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

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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

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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

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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

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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

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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

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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

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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

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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

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How Computer handles the task

Input

Store

Process

Output

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Parts of the Computer

Input Devices

Storage Devices

CPU

Output Devices

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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

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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

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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

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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

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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

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Central Processing Unit (CPU)

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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CPU Generations

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Architecture

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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

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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

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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

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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

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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

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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

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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

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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

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Input Devices

Key BoardTo Enter information and instructions into a computer

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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Multifunction Printers

• Can perform more than one task

• Often able to work as:Fax machine Scanner Photocopier Printer

• Color multifunction printers are also available

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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

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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.

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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