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COMPUTING FUNDAMENTALS
LECTURE 3 : WEEK 3CSC-110-T : FALL 2015
Credit : (2 + 1) / Week
TEXT AND REF. BOOKS2
Text Book:
Peter Norton (2011), Introduction to Computers, 7 /e, McGraw-Hill
Reference Book:
Gary B (2012), Discovering Computers, 1/e, South Western
Deborah (2013), Understanding Computers, 14/e, Cengage Learning
June P & Dan O (2014), New Perspective on Computer, 16/e
MOBILE ALERTKindly Switch Off your Mobile/Cell Phone
OR
Switch it to Silent Mode Please
3
GOOGLE SITE ADDRESS
FOR LECTURE NOTES AND STUDY MATERIAL
DOWNLOAD, PLEASE VISIT :
https://sites.google.com/site/shucsc110/
OR
TYPE “SHUCSC110” & GOOGLE
4
MSc. Telecomm. & Network Management, UK
Masters (CS), Bahria University Khi, Pakistan
Prince2 Project Management (Foundation) Certified
Microsoft Certified Professional (MCP)
Presented by: Flt. Lt. Shujaat H. Butt (R)
INPUT/OUTPUT/STORAGE DEVICES
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Learning Outcome Input Devices Keyboard, Mouse, Touchscreen etc Output Devices Monitors, Printers etc Storage Devices Hard Disk Drive, Optical Storage etc
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Input Input is any data and instructions
entered into the memory of a computer
Input Device is any hardware component that allows users to enter data and instructions into a computer
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Input
Input Device: Keyboard and pointing devices
Pointing devices: Mouse is a pointing device because it allows a user to control a pointer on the screen.
Input In Graphical User Interface (GUI), a
pointer is a small symbol on the screen whose location and shape change as a user moves a pointing device.
A pointing device can select text, graphics and other objects and click buttons, icons, links and menu commands.
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Input Mouse There are 2 types: Mechanical mouse and Optical mouse. Mechanical mouse has a rubber or metal ball on its
underside. You should place a mechanical mouse on a mouse pad. Mouse pad is a rectangular rubber or foam pad that provides
better traction than the top of a desk Optical mouse uses devices that emit and sense light to
detect the mouse’s movement.
Input
Input
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Input Mouse Optical mouse is
More precise than a mechanical mouse Dose not require cleaning as does a mechanical mouse. Also it is more expensive.
Mouse connects to a computer in several way: By cable through mouse port, USB port and serial port (old). By wireless through IR or Bluetooth.
Wireless mouse or cordless mouse, is a battery-powered device that transmits data using wireless technology.
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Input The Keyboard Is an input device that contains keys users press to
enter data and instructions into a computer Desktop computer keyboard often attach to the
System Unit using Cable: a serial port or USB port. Without cables : IR or Bluetooth
Wireless keyboard or cordless keyboard, is a battery-powered device that transmits data using wireless technology
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Computer Keyboard Keys
Function Keys Cursor-Movement Keys Numeric Keypad Toggle Keys (Caps Lock, Num Lock) Modifier Keys (Shift, Alt, Ctrl) Windows Keys Print Screen
Standard Computer Keyboard16
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Input Scanners and Reading Devices Some input devices save time by capturing
data directly from a source document Optical scanner Optical readers Bar code readers RFID readers Magnetic strip card readers
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Input Optical Readers
Is a device that uses a light source to read characters, marks and codes and then converts them into digital data that a computer can process.
Two technologies used by optical readers are
Optical character recognition.
Optical mark recognition.
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Input 3- Bar Code Readers Also called bar code scanner
Is an electronic device that uses laser beams for reading printed barcodes.
Barcode is an identification code that consists of set of vertical lines and spaces of different widths
The barcode represent the data that identifies the manufacturer and the item
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Input And Output 4- RFID Readers Radio-frequency identification Is a technology that uses radio signals to communicate with
a tag placed in or attached to an object, an animal, or a person.
RFID tags, which contain a memory chip and an antenna, are available in many shapes and size.
RFID reader reads information on the tag via radio waves. It can be handheld devices or mounted in a stationary object such as a doorway.
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Input 5- Magnetic Strip Card Readers Often called a mag-strip reader, reads the Magnetic strip on
the back of credit cards or other similar cards. The strip contains information identifying you. Some information stored in the strip includes your name,
account number, the card expiration date, and a country code. If the Magnetic strip card readers rejects your card, it is
possible that the Magnetic strip is scratched, dirty or erased. Exposure to magnetic field can erase the contents of a card’s
magnetic stripe.
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Input Biometric Input
Is the technology of authenticating a person’s identity by verifying a personal characteristic.
Biometric devices grant users access to programs, systems, or rooms by analyzing some physiological or behavioral characteristic.
Such as fingerprints, eye patterns, voice patterns, facial features, signatures and hand geometry.
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Input Biometric Input
Fingerprint scanner Face recognition system Hand geometry system Voice verification system Signature verification
system Iris recognition system
What is Output ? Any information that has been processed
and comes from a computer or computer device is considered as output
When someone is viewing output, they're seeing it on an output device such as a computer monitor or a hard copy print out.
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Output Device An output device is any piece
of computer hardware equipment used to communicate the results of data processing carried out by an information processing system (such as a computer) which converts the electronically generated information into human-readable form
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Output Devices Processed data from a computer Text, graphics, photos, audio, video Common output devices
Monitor Printer Plotter Voice
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Monitors Most frequently used output
device
Size is measured by diagonal of
screen
Common sizes: 15, 17, 19, 21
inches
Clarity is indicated by resolution
Measured in pixels
More pixels = better clarity
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Monitor Standards
Resolution capabilities indicated by a monitor’s
standard
Video Graphics Array (VGA)
Super Video Graphics Array (SVGA)
Extended Graphics Array (XGA)
Super Extended Graphics Array (SXGA)
Ultra Extended Graphics Array (UXGA)
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Monitor Types
Cathode-Ray Tubes (CRT) Most common
Flat-panel monitors (Liquid Crystal Display) Passive-matrix
images created by scanning the entire screen
Active-matrix (Thin Film Transistor TFT) each pixel is individually activated
eBook readers Data projectors High-definition television (HDTV)
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Printers Produces hard copy output Ink-jet printer
Inexpensive and for home use
Sprays droplets of ink
Produce very sharp images Laser printer
More expensive, fast printing speed
Laser produced excellent letter and images
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Laser Printing
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Other Printers Dot-matrix
Series of pins on print head Inexpensive, not high quality
Chain/Line printer Used on networks by Org.
Plotter Maps, architectural drawings High quality, larger sized output
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Output Devices Optical Disks: CD-ROM and DVD
CD-ROM (Compact Disk - Read Only Memory) By its definition, CD-ROM is Read Only. Special CD drives “burn” information into blank CDs.
Burn: A laser is used to “burn” craters into the surface to represent a binary 1.
Two main types of CDs: CD-R (Compact Disk - Recordable) CD-WR (Compact Disk – Re-Writable)
It takes longer to write to a CD-R than a hard drive. Special software is needed to record.
Storage Devices
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Data Units
Name Equal to Size in Bytes Bit 1 bit 1/8 Byte 8 bits 1 Kilobyte 1,024 bytes 1,024 Megabyte 1,024 kilobytes 1,048,576 Gigabyte 1,024 megabytes 1,073,741,824 Terabyte 1,024 gigabytes 1,099,511,627,776
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Storage UnitsName What can it store?
Byte A single letter, like "A."
Kilobyte A 14-line e-mail. A pretty lengthy paragraph of text.
Megabyte A good sized novel.
Gigabyte Roughly 300 MP3s or 40 minutes of video at DVD quality. A CD holds about three quarters of a gigabyte.
Terabyte 1,000 copies of the Encyclopaedia Britannica. Statistically, the average person has spoken about this much by age 25!
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Storage: Holding Data for Future Use
Storage is dependent on two parts: Recording media to hold the data
Hard disks Flash memory CDs and DVDs
A storage device, which is hardware that contains the tools to place the data on the recording media
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Storage: Holding Data for Future Use
A hard disk drive (hard disk) is: The most important storage device A high-capacity, high-speed device Considered secondary storage (fixed
storage), compared with memory/RAM, which is categorized as primary storage
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Storage: Holding Data for Future Use
Hard disk drives Are random access storage devices and
permit direct retrieval of desired data Contain a coating of magnetic material used for data storage
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Storage: Holding Data for Future Use
Hard disks record data on concentric bands called tracks.
Tracks are divided into sectors.A group of two or more sectors is a cluster.
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Storage: Holding Data for Future Use
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Storage: Holding Data for Future Use
The computer’s operating system stores in a table the file name and its location on the disk. The File Allocation Table (FAT) is the table
created by older versions of Microsoft Windows. The New Technology File System (NTFS) is
the present system used for tracking file locations.
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Performance Measures of Disks
Access time – the time it takes from when a read or write request is issued to when data transfer begins. Consists of: Seek time – time it takes to reposition the arm over
that correct track. Rotational latency – time it takes for the sector to
be accessed to appear under the head.
Data-transfer rate – the rate at which data can be retrieved from or stored to the disk.
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Storage: Holding Data for Future Use
Hard disk performance Disk cache is a type of cache memory.
CPU looks in the disk cache before going to the hard disk.
Using the disk cache speeds up data retrieval.
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Tracks on a CD
A CD has one long track on it full of Pits and Lands.
This tracks begins at the centre of the disk and work outwards in a tight spiral.
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Reading and Writing to a CD-ROM
Powerful laser ‘burns’ disk surface
Laser ‘burns’ pits into surface
Weak laser reads surface
Detector measures reflected light
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How a CD-ROM is read
Data is encoded onto the CD using a series of ‘Pits' and ‘Lands‘.
A change from a Pit to a Land is read as a 1 and no change or a Land is read as a 0.
In this figure, it will read as: 01001010 Remember Your ASCII! Therefore 01001010 = 74 = Letter J 8 Bits = 1 Byte = 1 Character of TextLa
ser
Pit
Change Change Change
Land Land Pit Land
Light Sensor
Reflected Light
Top of CD ROM Disk
Bottom of CD ROM Disk
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Any Questions !!!
END OF LECTURE 748