Chapter 3 : Computer and Mobile Devices

Computer and Mobile Devices

Types of Computer .

1. Desktop and mobile computers

Example
Personal computer (PC)	- A computer that can perform all of its input, processing, output, and storage activities by itself and is intended to be used by one person at a time
Mobile computer	- Portable personal computer, designed so that a user easily can carry it from place to place
Desktop	- A personal computer designed to be in a stationary location, where all of its components fit on or under a desk or table
Laptop	- Thin, lightweight mobile computer with a screen in its lid and a keyboard in its base
Tablet	- A thin, lightweight mobile computer that has a touch screen
Handheld computer	-  A computer small enough to fit in one hand

2. Servers and terminals

Server

•       Computer dedicated to providing one or more services to other computers
 or devices on a network

–      Rack server

–      Blade server

–      Tower server

1.      Mainframe - a large, expensive, powerful server that can handle hundreds or thousands of connected users simultaneously

2.   Supercomputer -  the fastest, most powerful computer and the most expensive

Server Vs Supercomputer

SERVER	SUPERCOMPUTER
Serves bits and bytes of data that enter and leave the server	Regular hardware combined in enormous proportions
Web servers-processing requests from surfers and sending them back data	Contain so many processors
Web browsers - assemble that data to generate Web pages	Predict the weather, build airplanes, model the brain and simulate the way the planet works.
Server send files in a network.	Sequoia Blue Gene/Q supercomputer processing 504 billion events per second(2013) ≈1 million desktop computers.

Terminal

•   A computer, usually with limited processing power, that enables users to send data to and/or receive information from a server, or host computer

Example	Function
Point of sale (POS) terminal	- To record purchases, process credit or debit cards, and update inventory
Automated Teller Machine (ATM)	- A self-service banking terminal that connects to a host computer through a network

Cloud Computing

•       Refers to an environment of servers that house and provide access to resources
 users access through the Internet

3. Smartphones, digital cameras, e-book readers and portable media players

Mobile Devices

• Smartphone - an Internet-capable phone that usually also includes a calendar, an appointment book, an address book, a calculator, a notepad, games,browser, and numerous other apps
  
• Digital camera - a mobile device that allows users to take photos and store the photographed images digitally
  
• Portable media player - a mobile device on which you can store, organize, and play or view digital media
  
• E-book reader - a mobile device that is used primarily for reading e-books and other digital publications

4. Game Devices

• Game console - a mobile computing device designed for single-player or multiplayer video games
• Handheld game device - a small mobile device that contains a screen, speakers, controls, and game console all in one unit
•  Game controllers -  include gamepads, joysticks and wheels, dance pads, and a variety of motion-sensing controllers

5. Embedded computers

• Special-purpose computer that functions as a component in a larger product such as

- Consumer electronics
- Process controllers and robotics
- Home automation devices
- Automobiles
- Computer devices and office machines

6. Ports and Connection

Port

• The point at a peripheral device communicates with a computer or mobile device to send or receive information from the computer or mobile device
  
• USB port, short for universal serial bus port, can connect up to 127 different peripheral devices together with a single connector
  
• Port replicators or docking stations – use like a extension , the cable will not directly attach to peripheral devices

Connector

• The joins a cable to a port. A connector at one end of a cable attaches to a port on the computer or mobile device, and a connector at the other end of the cable attaches to a port on the peripheral device

Wireless Communication technology.

- some peripheral devices use wireless communications technologies like

                - WiFi
                - Bluetooth
                - NFC

Protecting Hardware

The reasons hardware can fail :

- Aging hardware
- Random events such as electrical power problems
- Errors in programs or apps such as Undervoltage, Overvoltage or power surge

Hardware Protector

1. A surge protector -

• uses electrical components to provide a stable current flow and minimize the chances of an overvoltage reaching the  computer and other electronic equipment

2. Uninterruptible power supply (UPS) - 

• a device that contains surge protection circuits and one or more batteries that can provide power during a temporary or permanent loss of power.

7. Health Concerns of Using Technology

•       A repetitive strain injury (RSI) - an injury or disorder of the muscles, nerves, tendons, ligaments, and joints

•       Computer vision syndrome (CVS) - a technology-related health condition that affects eyesight

•       Ergonomics - an applied science devoted to incorporating comfort, efficiency, and safety into the design of items in the workplace

•       Technology addiction - occurs when the technology consumes someone’s entire social life