CHAPTER 7

CHAPTER 7: input and output

7.1 INPUT

• Input is any data and instructions entered into the memory of a computer
• input method
  - keyboard
  - motion input
  - voice input
  - video input
  - touch screen
  - pen input
  - pointing devices
  - scanners and reading devices

7.1.1 KEYBOARD

• A keyboard is an input device that contains keys users press to enter data and instructions into a computer or mobile device
• An ergonomic keyboard has a design that reduces the chance of repetitive strain injuries
• Ergonomics incorporates comfort, efficiency, and safety into the design of the workplace

7.1.2 POINTING DEVICES

• A pointer is a small symbol on the screen whose location and shape change as a user moves a pointing device
• A mouse is a pointing device that fits under the palm of your hand comfortably
  - Optical mouse, laser mouse, and touch mouse

7.1.3 PEN INPUT

• With pen input, you touch a stylus or digital pen on a flat surface to write, draw, or make selections
• A graphics tablet, also called a digitizer, is an electronic plastic board that detects and converts movements of a style or digital pen into signals that are sent to the computer

7.1.4 MOTION INPUT

• With motion input, sometimes called gesture recognition, users can guide on-screen elements using air gestures

7.1.5 VOICE INPUT

• Voice input is the process of entering input by speaking into a microphone
• Voice recognition, also called speech recognition, is the computer or mobile device’s capability of distinguishing spoken words

7.1.6 AUDIO INPUT

• Audio input is the process of entering any sound into the computer such as speech, music, and sound effects
• Music production software allows users to record, compose, mix, and edit music and sounds

7.1.7 VIDEO INPUT 

• Video input is the process of capturing full-motion images and storing them on a computer or mobile device’s storage medium

7.1.8 SCANNERS AND READING DEVICES

• A scanner is a light-sensing input device that reads printed text and graphics and then translates the results into a form the computer can process
  - A flatbed scanner works in a manner similar to a copy machine except it creates a file of the document in memory instead of a paper copy
• An optical reader 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.
  - Optical character recognition (OCR)
  - Optical mark recognition (OMR)

7.2 OUTPUT

• Output is data that has been processed into a useful form

7.2.1 DISPLAYS

• A display visually conveys text, graphics, and video information
• A monitor is a display that is packaged as a separate peripheral device
  - LCD monitor
• To display the highest quality images, the monitor should plug into:
  - A DVI port
  - An HDMI port
  - A Display Port
• Home users sometimes use a digital television (DTV) as a display
• HDTV is the most advanced form of digital television
• A Smart TV is an Internet-enabled HDTV

7.2.2 PRINTERS

• A label printer is a small printer that prints on an adhesive-type material that can be placed on a variety of items
• Impact printers form characters and graphics on a piece of paper by striking a mechanism against an inked ribbon that physically contacts the paper
• A mobile printer is a small, lightweight, battery-powered printer that allows a mobile user to print from a mobile device

7.2.3 OTHER OUTPUT DEVICES

• A data projector is a device that takes the text and images displaying on a computer or mobile device screen and projects them on a larger screen
• Joysticks, wheels, gamepads, and motion-sensing game controllers can be considered output devices when they include force feedback
  -Technology that sends resistance to the device in response to actions of the user

CHAPTER 6

CHAPTER 6: INSIDE COMPUTERS AND MOBILE DEVICES

Inside the case

•  The case contains and protects the electronics of the computer or mobile device from damage
• The motherboard is the main circuit board of the computer - A computer chip contains integrated circuits

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Processors

•  The processor, also called the central processing unit (CPU), interprets and carries out the basic instructions that operate a computer
• Contain a control unit and an arithmetic logic unit (ALU)- A multi-core processor is a single chip with two or more separate processor cores
• The control unit is the component of the processor that directs and coordinates most of the operations in the computer
• The arithmetic logic unit (ALU) performs arithmetic, comparison, and other operations
• For every instruction, a processor repeats a set of four basic operations, which consist of a machine cycle
• The leading manufacturers of personal computer processor chips are Intel and AMD
•  A processor chip generates heat that could cause the chip to malfunction or fail
•  Require additional cooling
  - Heat sinks
  - Liquid cooling technology
  - Cooling mats

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Cloud Computing

·   Home and business users choose cloud computing for a variety of reasons
- accessibility
- cost savings
- space savings
- scalability

Data Representation

·         Analog signals are continuous and vary in strength and quality

·         Digital signals are in one of two states: on or off

Memory

• ·         Memory consists of electronic components that store instructions waiting to be executed by the processor, data needed by those instructions, and the results of processing the data
• ·         Read-only memory (ROM) refers to memory chips storing permanent data and instructions
• ·         Access time is the amount of time it takes the processor to read from memory
•       Measured in nanoseconds

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Adapters

·     An adapter card enhances functions of a component of a desktop or server system unit and/or provides connections to peripherals

· Sound card and graphics card

·    An expansion slot is a socket on a desktop or server motherboard that can hold an adapter card

·     With Plug and Play, the computer automatically can recognize peripheral devices as you install them

Power Supply and Battery

• ·         The power supply or laptop AC adapter converts the wall outlet AC power into DC power
• ·         Mobile computers and devices can run using either a power supply or batteries
• ·         Batteries typically are rechargeable lithium-ion batteries

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