Chapter Topics Chapter 2 Looking at Computers: Understanding the Parts Functions of a computer Data versus information Bits and bytes Input devices Output devices System unit Ergonomics 1

Computers Are Data Processing Devices 2

Data vs. Information Data: Representation of a fact, figure, or idea Information: Organized, meaningful data Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 3

Bits and Bytes: The Language of Computers Bit Binary digit 0 or 1 Byte Eight bits Each letter, number, and character = a string of eight 0s and 1s Example in the ASCII coding system the character ‘A’ is and ‘Z’ is

How Much Is a Byte? Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 5 NameAbbreviationNumber of BytesRelative Size ByteB1 byteCan hold one character of data. KilobyteKB1,024 bytes (2 10 bytes)Can hold 1,024 characters or about half of a double-spaced typewritten page. [Measure Word, Excel, and some picture files in KB] MegabyteMB1,048,576 bytes (2 20 bytes)Can hold ~768 pages of typed text. [Measure some picture files in MB] GigabyteGB1,073,741,824 bytes (2 30 bytes)Approximately ~786,432 pages of text which is a stack of paper ~262 feet high. [Measure older hard drives [750 GB] TerabyteTB1,099,511,627,776 bytes (2 40 bytes)This represents a stack of typewritten pages ~ 51 miles high. [Measure new hard drives (1-3 TB) in TB] PetabytePB1,125,899,906,842,62 bytes (2 50 bytes) The stack of pages is now 52,000 miles high, or approximately one- fourth the distance from the Earth to the moon. ExabyteEB1,152,921,504,606,846,976 bytes (2 60 bytes) The stack of pages is now 52 million miles high, or just about twice the distance between the Earth and Venus. ZettabyteZB1,180,591,620,717,411,303,424 bytes (2 70 bytes) The stack of pages is now 52 billion miles high, some 20 times the distance between the Earth and Pluto.

Metric prefixes prefixabbrev#word -- B1 byte kiloKB1,000 bytesthousand megaMB1,000,000 bytesmillion gigaGB1,000,000,000 bytesbillion teraTB1,000,000,000,000 bytestrillion petaPB1,000,000,000,000,000 bytesquadrillion 6

Computer Hardware Hardware: Any part of the computer you can touch. 7

Computer Software Software: Programs that enable hardware to perform different tasks Application software System software 8

Types of Computers -1 Notebook: Portable computer Desktop: Used at a single location Mainframe: Supports hundreds of users simultaneously Supercomputer: Performs complex calculations rapidly Embedded: Self-contained computer performing dedicated functions Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 9

Types of Computers -2 Netbook: precursor to tablets Tablet computer: examples are iPad, and Samsung Galaxy tab, Kindle Fire Tablet PC: full sized and featured laptop but with tablet writing and touch screen Ultrabook: ultra-slim but fully featured laptop All-in-one: example is the iMac Smartphones! 10

Input Devices Devices used to enter information or instructions into the computer Keyboard Mouse/ pointing device Microphone Scanner Digital camera Stylus 11

Keyboards The QWERTY layout is standard on most PCs Enhanced keyboard features include number, function, and navigation keys. 12

Notebook Keyboard trackpoint trackpoint touchpad touchpad number pad number pad Notebook keys – fn key in conjunction with function key does special function such as volume Notebook keys – fn key in conjunction with function key does special function such as volume 13 trackpoint Touchpad Fn key

Dvorak Keyboards Puts the most commonly used keys on “home keys” Reduces distance of finger stretches Not enough interest to change from QWERTY though 14

Virtual type keyboards Virtual laser keyboard Virtual on-screen keyboard and add-on keyboard Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 15

Electronic writing Stylus writing tool Digital pen: transmits what you “write” to other device. Transfer file to computer later. 16

Wireless RF keyboard With the RF (radio frequency) wireless technology, the keyboard contains a transmitter that transmits the radio waves to a receiver that sits next to the keyboard and is attached to the tower. Bluetooth wireless keyboard is a shorter range wireless © 2008 Prentice-Hall, Inc. 17

Mice Mechanical mouse - a Optical mouse - in B501! - c Trackball - b Easier on wrists Stays stationary on desk Wireless Radio or light waves - d Integrated pointing device Touchpad (or trackpad) Trackpoint - e 18 use-mouse/ d e

Other Input Devices Scanners Text Images Digital cameras Images Video 19 Flatbed scanner Handheld scanner Digital camera Camcorder

Other Input Devices Game controllers Touchscreens on devices such as the: smartphone tablet computer (top) tablet PC (bottom) Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 20

Image Input Digital cameras, camcorders, and cell phones Pictures Video Webcams Live video Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 21

Inputting Sound Microphones used for: Podcasts Video conferencing Internet phone Speech recognition Types: omni-directional uni-directional clip-on close-talk (headset pictured) 22

Input Devices for the Physically Challenged Visual impairments Voice recognition Keyboards with large keys On-screen keyboards Motor control issues Special trackballs Head-mounted devices 23

Output Devices Send processed data out of the computer Monitors Printers Output devices make: Soft copies (video, sounds, control signals) Hard copies (print) 24

Monitor types CRT Cathode Ray Tube Legacy (as in “old”) LCD Liquid Crystal Display © 2008 Prentice-Hall, Inc. 25

LCD Monitor Features Screens are grids made up of millions of pixels. pixel = picture elements, grid of millions of tiny dots on screen Each pixel is composed of yellow, red, blue, green subpixels. LCD: Liquid crystal, light waves, etc result in variations of colors to form the image on the screen. LED (Light emitting diode) and OLED (“O” for organic) are newer technologies OLED Doesn’t require back-lighting 26

LCD Quality Factors Resolution -Total number of pixels on screen; the more pixels there are (higher resolution values) the clearer the image on the screen -A larger resolution fits more on screen (images are smaller); Smaller resolution fits less (images are larger) Right-click on Desktop, select Screen Resolution (or Personalization, and Adjust resolution). -“…buy a monitor with the highest resolution available for the screen size.” 27

Resolutions and screen size 27” monitor: 2560x1440 pixels (typical resolution) 19” monitor: Some resolutions: 1440x900, 1280x1024 At least 1920x1080 for HD hi-def movies Wide screen vs. standard 4:3 ratio; wide good for 2 documents viewed at once... Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 28

LCD Quality Factors Resolution -total # of pixels on screen; the more the pixels (higher resolution values) the clearer the image on screen -A larger resolution fits more on screen (images are smaller); Smaller resolution fits less (images are larger) Right click on Desktop select Screen Resolution. 29

Other Video Output Monitors w/ built-in cam, mic, card reader, USB hub Data projectors Project a computer image to wall for sharing with group 30

Printers Impact printers Dot-matrix Nonimpact printers Inkjet Laser Specialty printers All-in-one Plotters (print blueprints out) Thermal printers (wax paper, heat, burning dots onto paper) 31

Nonimpact Printers Inkjet and Laser Inkjet ( spray tiny drops of ink. ) Entry level model is less expensive Full color printing – excellent choice for photo printing Laser (uses toner) There are B & W laser printers and color laser printers (Color lasers very expensive) Excellent quality, quiet © 2008 Prentice-Hall, Inc. 32 When purchasing a printer consider price of consumables (ex: cartridges and toner), speed (ppm, pages per minute), resolution (dpi, dots per inch), memory, color

The Motherboard CPU RAM (S+T) Expansion cards and slots Built-in components S + T = Show n Tell 33

Expansion Cards Add functions Provide new connections for peripheral devices Common types: Sound Modem (telephone) Video (VGA or graphics) Network (NIC=network interface card) 34

RAM vs. ROM Random access memory (RAM): Stores instructions and data Temporary (volatile) storage Consists of several memory cards or modules Read-only memory (ROM): Stores start-up instructions Permanent storage Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 35

Memory Module Random access memory (RAM) Copy of program instructions/data in RAM when program running Temporary (volatile) storage Operates in nanosec. Common size: 4GB to 24 GB Chap 6 mentions that Windows 8 64-bit OS allows for up to 192 GB of RAM! 36

Central Processing Unit (CPU) Referred to as the “brains” of the computer Controls all functions of the computer Processes all commands and instructions Can perform billions of tasks per second Common speeds: 2.5 GHz laptop, 3.8 GHz desktop 37

CPU Performance Measures 3.8 GHz ~ 3.8 billion machine cycles per sec 1 hertz is approx. 1 machine cycle per second Performance also dependent on # of cores (simultaneous paths executing instruct’s; (see picture) Single core Dual core (2) Quad core(4) Eight cores (8) Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 38

Drive Bays Internal drive bays: Cannot be accessed from outside the system Are reserved for internal hard drives External drive bays: Can be accessed from outside the system CD or DVD drives Floppy and Zip drives (legacy) Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 39

The Front Panel Power control Drive bays Memory card reader Productivity ports 40

Hard Drive Permanent storage Magnetic techn. Internal or external versions Stores data, programs Does tasks in millisecs (1/1000 sec) vs RAM’s nanosecs (1/1000,000,000 sec) (Spin rate: 5400, 7200 rpm mentioned on optional page of reading) Common: 750 GB, 1TB up to 8TB (T=Tera, trillion) Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 41

Optical Storage Going from CD, to DVD to Blu-ray (BD) drives, their size capacities and speeds increase. Compact discs (CDs) Digital video discs (DVDs) Blu-ray discs (BDs) Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 42

Permanent Storage Media See teacher hand-out Disk sizes 43

Solid state flash memory Flash drives (see pics  ) also called jump drives, USB, thumb) Plug into USB ports Flash memory cards Slide into slots in the system For cameras, smartphones Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 44

Types of Ports VGA and DVI Audio ports USB FireWire Ethernet Telephone Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 45

© 2008 Prentice-Hall, Inc. 46 Ports for peripheral devices speeds in bits per sec = bps –Serial, and parallel 115 and 500bps, –Serial, and parallel 115 and 500bps, legacy –USB 480M bps (2.0) –USB 4800M bps (3.0) –Ethernet: –100/1000/10,000M bps –Tele. modem 56K bps –FireWire (or 1394) 400M bps, 800M bps, and 3.2G bps (= 3200M bps) –Audio ports –VGA and DVI (monitor) –HDMI (TV, monitor home theatre ) –Thunderbolt 10 G bps

Adding Ports add more ports with internal expansion card or with external expansion hub Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 47

Power Controls Power-on button: Turns on system; Use Shut Down procedure or may use Power button to turn off. Called a cold boot when turned on for the first time that day (Warm boot is restart) Keep computer on but use conservation of energy: Sleep mode, Hibernate Only turn off computer if use it very little Change power settings: Control Panel (icon view) > Power Options Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 48

Ergonomics (1) Ergonomics – procedures, equipment for minimizing injury or discomfort while using the computer (minimize RSI - repetitive stress injury) Steps to follow: – Position monitor correctly (eyes) at top of monitor – Use adjustable chair (back of knees not pressed against chair that is too high, feet on floor) – Wrists flat over keyboard, not presses on edge of table – Take breaks – Ensure adequate lighting © 2008 Prentice-Hall, Inc. 49

Ergonomics (2) Play PMPs (personal media players) at 60 decibels or less Small screens – blink often, take a break to focus at 8ft Backpack – place over both shoulders not one © 2008 Prentice-Hall, Inc. 50

Chapter 2 Summary Questions What are the 4 main functions of a computer? What are the 4 main functions of a computer? What is the difference between data and information? What is the difference between data and information? What are bits and bytes, and how are they measured? What are bits and bytes, and how are they measured? What devices do you use to get data into the computer? What devices do you use to get data into the computer? What devices do you use to get information out of the computer? What devices do you use to get information out of the computer? What’s on the motherboard? What’s on the motherboard? Where are programs and information stored? Where are programs and information stored? How are devices connected to the computer? How are devices connected to the computer? How do you set up your computer to avoid strain and injury? How do you set up your computer to avoid strain and injury? 51