CHAPTER 7 : INPUT AND OUTPUT

INPUT

• ·         Any data and instructions entered into the memory of a computer

Commonly used in :

Devices	Description	Example
Keyboard	Input device that contains keys users press to enter data and instructions into a computer or mobile device.	Ergonomic keyboard  Design to reduces the chance of repetitive strain injuries Incorporates comfort, efficiency, and safety into the design of the workplace.
Pointing devices	Pointer with a small symbol on the screen whose location and shape change as a user moves a pointing device.	Mouse A pointing device that fits under the palm of your hand comfortably. Example : Optical mouse, laser mouse, and touch mouse. Touchpads A small, flat, rectangular pointing device that is sensitive to pressure and motion. Pointing Stick A pressure-sensitive pointing device shaped like a pencil eraser that is positioned between keys on a mobile computer keyboard Trackball A stationary pointing device with a ball on its top or side
Pen Input	Easier for users to touch on a flat surface using a stylus or digital pen to write, draw, or make selections.	Graphics Tablet An electronic plastic board that detects and converts movements of a style or digital pen into signals that are sent to the computer.
Motion Input	Known as gesture recognition, users can guide on-screen elements using air gestures	Joysticks, wheels, gamepads Technology that sends resistance to the device in response to actions of the user
Voice Input	The process of entering input by speaking into a microphone	Speech recognition  The computer or mobile device’s capability of distinguishing spoken words
Audio Input	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
Video Input	The process of capturing full-motion images and storing them on a computer or mobile device’s storage medium	Webcam Digital video (DV) camera that can :  Capture video and still images Send email messages with video attachments Add live images to instant messages Broadcast live images over the Internet Make video calls Conduct videoconferences
Scanners and Reading Devices	A light-sensing input device that reads printed text and graphics and then translates the results into a form the computer can process	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 Bar code reader ·         Known as bar code scanner uses laser beams to read bar codes QR code ·         Stores information in both a vertical and horizontal direction Magstripe Readers ·         Read the magnetic stripe on the back of cards such as credit card , bank card and other card.

OUTPUT

·         Data that has been processed into a useful form.

Output Devices

Display -   Visually conveys text, graphics, and video information	Monitor ·         A display that is packaged as a separate peripheral device such as LCD monitor ·         To display a high quality image monitor should plug into: 1.  A DVI port 2.  An HDMI port 3.  A Display Port HDTV The most advanced form of digital television that the user uses home as display. Data projector  Device that takes the text and images displaying on a computer or mobile device screen and projects them on a larger screen
Printer - Produces text and graphics on a physical medium	Nonimpact printer Forms characters and graphics on a piece of paper without actually contacting the paper. Example :- Ink-jet printer - forms characters and graphics by spraying tiny drops of liquid ink onto a piece of paper Laser Print       - A high quality printer that produce a high quality copy.          All-in-one printer  - A single device that prints, scans, copies, and in some cases, faxes  Thermal printer - Generates images by pushing electrically heated pins against the heat-sensitive paper  Mobile printer - Allows a mobile user to print from a mobile device Label - A small printer that prints on an adhesive-type material that can be placed on a variety of items
Speakers -   Attach surround sound and generate higher-quality sounds	Headphones  Speakers that cover or are placed outside of the ear. Earbuds (also called earphones) Rest inside the ear canal to make users listen sharply.
Assistive Technology Input and Output	Braille input Braille printer

Chapter 6 : Inside Computer And Mobile Devices

1. Inside The Case of Dekstop and Laptop

Component	Function
- Motherboard	A computer chips contains integrated circuit
- Processor / Central Processing Unit (CPU)	Interprets and carries out the basic instructions that operate a computer 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
- Arithmetic Logic Unit (ALU)	Performs arithmetic, comparison, and other operations It represents the fundamental building block of the central processing unit (CPU) of a computer.
- Control Unit	The component of the processor that directs and coordinates most of the operations in the computer It tells the computer's memory, arithmetic/logic unit and input and output devices how to respond to a program's instructions.
- Heat Sinks - Liquid cooling technology - Cooling mats	Cooling the CPU / Devices

2. Cloud Computing

Refers to sharing resources, software, and information via a network, in this case the Internet. The information is stored on physical servers maintained and controlled by a cloud computing provider such as iCloud, Dropbox, Google Drive .

People always use it for:

• ·         Space Savings
• ·         Accessibility
• ·         Cost Saving
• ·         Scalability 

3. Data Representation.

•          Analog signals are continuous and vary in strength and quality

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

In the digital computer, data represent using binary system. The binary system uses two unique digits (0 and 1).

•         The circuitry in a computer or mobile device represents the on or the off states electronically by the presence or absence of an electronic charge
•         Eight bits grouped together as a unit are called a byte. A byte represents a single character in the computer or mobile device

4. Memory

•  Memory’s function is to store instructions waiting to be executed by the processor, data needed by those instructions, and the results of processing the data.
•   It store 3 basic categories items :

Ø  The operating system and other programs

Ø  Applications

Ø  Data being processed and the resulting information

•    Flash Memory - can be erased electronically and rewritten the data . Very useful when you need to transfer the data to another devices without using networking .
•    Access Time - the amount of time(nanoseconds) the processor takes to read from memory.
•    In memory, there is two system unit :

Volatile memory	Nonvolatile memory
Ø  Loses its contents when power is turned off Ø  Example includes RAM	Ø  Does not lose contents when power is removed Ø  Examples include ROM(memory chips storing permanent data and instructions), flash memory, and CMOS

5. Adapter

• An adapter is a physical device that allows one hardware or electronic interface to be adapted (accommodated without loss of function) to another hardware or electronic interface. In a computer, an adapter is often built into a card that can be inserted into a slot on the computer's motherboard.

Component	Function
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 –      Pendrive or projector
Expansion Slot	A socket on a desktop or server motherboard that can hold an adapter card
Plug and Play	Allow computer automatically recognize peripheral devices.

6. Power Supply and Battery

Mobile computers and devices can run using either a power supply or batteries

Power Supply (laptop AC adapter)	Battery
Converts the wall outlet AC power into DC power	Rechargeable lithium-ion batteries supply power to devices such as laptop and handphone