Chapter 2 - Hardware 2.2 Input and Output Devices Grading:

Notes: ______/20 Lesson Review: ______/20 Application Ext: _____/20 Input devices: _____/20 Output devices _____ / 20 Total points: _____/100

Essential Question  Why is it important for input and output devices to be accessible to people with disabilities?

Competencies  6670.49 Describe characteristics and functions of CPUs, , random access memory (RAM), expansion connections, hard drives, and CD-ROM drives.

Section 2.2 Learning Goals After completing this section, you will be able to:  Discuss input devices and their functions.  Describe output devices and their functions. Terms  audio-input devices   audio-output device   data projector  ripping  image-input devices  stylus  keyboard  text-input devices  monitor  touch screen  mouse  user interface (UI)  optical-character recognition (OCR)   output device

Input Devices and Their Functions  The means by which the user enters data and receives feedback is the user interface ( )  Keyboards o Device for textual and numeric data o Most basic

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o Actions of Keyboards . Electrical signal is sent to CPU . CPU processes signal and provides to software  Keyboards o Types of Keyboards o QWERTY . Dvorak . Virtual  Factors in Evaluating Keyboards o Choose a keyboard that the intended use o Maintain comfort

 Pointing Devices o Allows the user to control the of the cursor on the screen o Mouse is most common type o Actions of Pointing Devices . Pointing . Clicking . Dragging . Double-clicking o Types of Pointing Devices . is a device with one or more buttons that can be moved on a flat surface to control the cursor . . . is a pen-like pointer, but without ink o Factors in Evaluating Pointing Devices . Should support the use of the . Wired or wireless  Screens o Device that senses applied pressure and sends signals to the CPU o Actions of Touch Screens . Finger or stylus is used to apply pressure . Provides the basic functions of a pointing device o Types of Touch Screens . Tablets, smartphones, portable gaming devices . Interactive kiosks o In Evaluating Touch Screens . Accuracy of the pressure response . Size of areas for touching  -Input Devices o Used to digitize images so they can be used by the computer o Actions of Image-Input Devices . Use electronics to create electrical signals to represent data . and digital cameras digitize images based on light o Types Of Image-input Devices 2

. camera . Webcam is an image-input device that can be mounted on top of a monitor or built into a laptop computer o Factors in Evaluating Image-Input Devices . Higher density . Page feeder on scanner  -Input Devices o Generally, image-input devices used with software to convert the image to text that can be used by the computer o Actions of Text-Input Devices . Optical-character recognition (OCR) is software used with image to digitize text . Checks, typewritten documents, hand-written notes o Type of Text-Input Devices . Scanner with OCR software . Smartphones o Factors in Evaluating Text-Input Devices . intended use . Resolution and speed . OCR software  -Input Devices o Convert sounds into data that can be used by the computer o Actions of Audio-Input Devices . Sampling . Typical sampling rate for CD quality is 44,100 times per second o Types of Audio-Input Devices . . is the process of extracting audio from a CD, DVD, or file o Factors in Evaluating Audio-Input Devices . Supports intended use . Tonal qualities  Input Devices for Users with Disabilities o of Accessible Input Devices . Depends on the nature of the disability . Purpose is the same as any other input device o Types of Accessible Input Devices . -recognition technology . Enlarged keyboard and touch-screen devices o Factors in Evaluating Accessible Input Devices . Simple and intuitive . Error rate Output Devices and Their Functions . Output device makes it possible for the user to communication from the computer . Monitors o Provide display outputs o Displays graphical interface o Actions of Monitors 3

. Each pixel is a tiny point of light . Current comes from CPU via the . Monitors o Types of Monitors . Liquid crystal display ( ) . Light-emitting diode ( ) . Cathode-ray tube ( ) . Factors in Evaluating Monitors . Screen size o Contrast ratio o Dot pitch o Resolution . Projectors o Data projectors collect video data from a computer and the images onto a separate screen o Actions of Projectors . Works like a monitor . Signal passes through a to separate signal into RGB, then recombine into a single beam projected onto a screen . Projectors o Types of Projectors . LCD, DLP, LCoS, LED . Choose type that best serves purpose . in Evaluating Projectors o Size o Weight . Printers o Transform computer information into a physical form o Actions of Printers . page based on the output from another software program . Deposits ink or toner onto paper based on instructions from driver . Printers o Types of Printers . Ink-jet and are widespread . Solid-ink, 3-D o Factors in Evaluating Printers . Speed . Resolution . Duty cycle . Cost . -Output Devices o Convert data in the computer into sounds o Actions of Audio-Output Devices . Uses decompression instructions to create the file . Replicated by hardware of device o Types of Audio-Output Devices 4

. Basic speakers, headphones, earbuds . Mixing board and advanced stereo systems o Factors in Evaluating Audio-Output Devices . Should support intended use . . Output Devices for Users with Disabilities o Actions of Accessible Output Devices . Depends on nature of disability . of device is same as noncompliant device o Types of Accessible Output Devices . Larger monitors, magnification program, screen reader . Braille printer, closed captioning o Factors in Evaluating Accessible Output Devices . Simple and intuitive . Error rate

Chapter 2: Hardware

Section 2.2 Review

1. What is the function of the user interface?

2. Which input device senses applied pressure and sends signals to the CPU while providing the function of a ?

3. How does the purpose of an input device for users with disabilities differ from the purpose of a noncompliant device?

4. What is the most common output device?

5. What are the four factors to consider when evaluating an ink-jet or laser printer?

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Multiple Choice:

6. Which is the most common type of computer monitor in use today?

a) LCD b) CRT c) LED d) HD 7. Which of the following computer provides input? a) mouse b) touch pad c) keyboard d) All of the above. 8. Which of the following computer peripherals provides output? a) printer b) RAM c) microphone d) All of the above.

Completion

9. In the United States, the most common keyboard is the layout.

10. The is the most common output

Application and Extension of Knowledge Select a type of printer to research. Locate information regarding its cost of operation. Most manufacturers provide this information in sales or technical literature. Identify the specific ink or toner cartridge(s) the printer uses, and price the replacements from three different stores. Use Google Docs or Word

Include:  Printer Name  Who manufactures  What type of printer it is  Type of ink/toner uses  Price for inks  Picture of the printer

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Identify the Alternative OUTPUT Devices

Write the device name by the identification number provided

(1)______(2)______(3)______

(4)______(5)______(6)______

(7)______(8)______(9)______

(10)______(11)______(12)______

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Identify the Alternative INPUT Devices

Write the device name by the identification number provided

(1)______(2)______(3)______

(4)______(5)______(6)______

(7)______(8)______(9)______

(10)______(11)______(12)______9