MKA Chapter 9 : Operating system

 OPERATING SYSTEMS.

1.  What is operating system (OS)?

- a set of programs containing instructions that work together to coordinate all the activities among      computer and mobile device hardware.

ü  Start and shut down a computer or mobile device.

ü  Provide a user interface.

ü  Manage programs and memory.

ü  Coordinate tasks and configure devices.

ü  Monitor performance and establish Interner connection.

ü  Provide file management and other device/media related tasks

ü  Updating operating system software and control network.

2.  How to starting computers and mobile devices.

    -if a computer or mobile devices is off, you press a power button to turn it on.

3.  User interface (UI).

    -controls how you enter data and instructions and how information is displayed on the screen.

    -with a graphical user interface (UI), you interact with menus and visual images.

4.  How an operating systems handles programs directly affects you productivity?

ü  Single tasking and multitasking.

ü  Foreground and background.

ü  Single user and multiuser.

5.  Memory management optimizes the use of the computer or device’s internal memory.

6.  Virtual memory is a portion of a storage medium functioning as additional RAM.

7.  The operating systems determines the order in whish tasks are processed.

    -a driver is a small that tells the operating system how to communicate with a specific device.

    -plug and play automatically configures new devices as you install them.

8.  Operating systems typically provide a means to establish Internet connections.

9.  Operating systems often provide users with a variety of tools related to managing a computer, its device, or its programs.

ü  File manager and image viewer.

ü  Uninstaller and disk cleanup.

ü  Disk defragmenter and file compression.

ü  Search and pc maintenance.

ü  Backup and restore.

10.  Automatic update automatically provides new features or corrections to the program.

11.  A user account enables a use to sign in to, or acces resources on, a network or computer.

    -a username, or user ID, identifies a specific user.

    -a password is a private combination of characters associated with the user name.

                                                                        

12.  A desktop operating systems is a complete operating systems that works on desktops, laptops, and some tablets.

ü  Windows.

ü  Mac OS.

ü  UNIX.

ü  Linux.

13.  Windows 8 offers these features :

ü  Start screen interface with tiles.

ü  Includes yhe desktop interface.

ü  Support for input via touch, mouse, and keyboard.

ü  Email app, calendar app, and browser included.

ü  Enhanced security through an antivirus program, firewall, and aoutomatic updates.

ü  Windows Store offers additional applications for purchase.

14.  The Macintosh operating systems has earned a reputation for its ease of use.

    - latest version is OS X.

15.  UNIX is a multitasking operating system developed in the early 1970s

16.  Linux is a popular, multitasking UNIX-based operating system.

Server operating systems.

ü  Windows server.

ü  OS X server.

ü  UNIX.

ü  Linux.

Mobile operating system.

-the operating system on mobile devices and many customer electronics is called a mobile operating system and resides on firmware.

ü  Android. (an open sources, Linux-based mobile operating system designed by Google for smartphones and tablets)

ü  iOS. (developed by Apple, is a proprietary mobile operating system specificially made for Apple’s mobile device)

ü  Windows Phone. (developed by Microsoft, is a propriertary mobile operating system that runs on some smartphone)

Summary.

    -functions common to most operating systems.

    -variety of desktop operating systems, server operating systems, and mobile operating systems.

MKA Chapter 8 : Digital Storage

Digital storage

Storage

l  A storage medium is the physical material on which a computer keeps data, information, programs, and applications

l  Cloud storage is another storage option, in which the actual online storage media used is transparent to the user

Hard disk

l  A hard disk contains one or more inflexible, circular platters that use magnetic particles to store data, instructions, and information

Flash memory storage

l  Flash memory chips are a type of solid state media and contain no moving parts

l  It has 2 types whivh is SSD (solid state drive) HDD

Cloud storage

l  Cloud storage is an Internet service that provides storage to computer  or mobile device users

Optical disc

l  An optical disc consists of a flat, round, portable disc made of metal, plastic, and lacquer that is written and read by a laser

l  A DVD-ROM is a high-capacity optical disc on which users can read but not write on or erase

l  A DVD-R or DVD+R are competing DVD-recordable WORM formats, on which users can write once but not erase

l  DVD-RW, DVD+RW, and DVD+RAM are high-capacity rewritable DVD formats

Other Types of Storage

l  A magnetic stripe card contains a magnetic stripe that stores information

l  A smart card stores data on an integrated circuit embedded in the card

l  Radio Frequency Identification (RFID)

l  The RFID tag consists of an antenna and a memory chip that contains the information to be transmitted via radio waves

l  An RFID reader reads the radio signal and transfers the information to a computer or computing device

MKA Chapter 7 : Input Devices

INPUT DEVICES

l  Input is any data and instructions entered into the memory of a Computer

Pointing Devices

A pointer is a small symbol on the screen whose location and shape change as a users moves a pointing devices

l  A mouse is a pointing device that fits under the palm of your hand comfortably

l  Optical mouse, laser mouse, and touch mouse

Touchpad A touchpad is a small, flat, rectangular pointing device that is sensitive to pressure and motion

Pointing stick A pointing stick is a pressure-sensitive pointing device shaped like a pencil eraser that is positioned between keys on a mobile computer keyboard

Trackball A trackball is a stationary pointing device with a ball on its top or side

Keyboards

Most desktop computer keyboards have:

l  Typing area

l  Function keys

l  Toggle key

l  Directional keys

l  Media control buttons

l  Internet control buttons

There are various types of keyboards in addition to standard keyboards found on desktops

                           

·         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

OUTPUT DEVICES

·         Output is data that has been processed into a useful form.

Printers

·         A printer produces text and graphics on a physical medium

·         Type of printers :

-       Ink-jet printers

-       Photo printers

-       Laser printers

-       All-in-one printers

-       Thermal printers

-       Mobile printers

-       Plotters

-       Large-format printers

Ink-jet Printers

•      forms characters and graphics by spraying tiny drops of liquid ink onto a piece of paper

•      Color or black-and-white

•      Speed is measured by the number of pages per minute (ppm) it can print

Photo Printers

•      Produces lab-quality pictures

•      Many use ink-jet technology

•      Pictbridge allows you to print photos directly from a digital camera.

•      Print from a memory card.

Laser Printer

•      High speed

•      Produces high quality printed photos

•      Able to print either colour or in black and white

Thermal Printers

•      generates images by pushing electrically heated pins .against the heat-sensitive paper

Plotters

•      used to produce high-quality drawings

•      Large-format printers create photo-realistic quality color prints

Mobile printer

·         a small, lightweight, battery-powered printer that allows a mobile user to print from a mobile device

Label Printers

·         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

Data Projector

·         a device that takes the text and images displaying on a computer or mobile device screen and projects them on a larger screen.

MKA Chapter 6 : Inside Computers and Mobile Devices

INSIDE COMPUTERS AND MOBILE DEVICES

Inside the case

·         The case contains and protects the electronics of the computer or mobile device from damage

·         Electronics components such as video card, power supply and fan, battery, sound card, processor and others.

Motherboard

 The motherboard is the main circuit board of the computer; a computer chip contains integrated circuits.

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

·         For every instruction, a processor repeats a set of four basic operations, which consist of a machine cycle. All the basic operation are, fetch, decode, execute, store.

·         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 broke it. So require additional such as cooling Heat sinks , Liquid cooling technology, Cooling mats.

Cloud Computing

·         Home and business users choose cloud computing for a variety of reasons like, accessibility, cost saving, space saving and scalability.

Data Representation

·         Analogue signals are continuous and vary in strength and quality and digital signals are in one of two states: on or off.

·         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.

·         Stores three basic categories of items; The operating system and other programs, Applications, Data being processed and the resulting information.

·         The system unit contains two types of memory: Volatiled memory and nonvolatiled memory.

·         Volatile memory will loses its contents when power is turned off such as RAM.

·         Nonvolatile memory does not lose contents when power is removed such as  ROM, flash memory, and CMOS devices.

Adapters

·         An adapter card enhances functions of a component of a desktop or server system unit and/or provides connections to peripherals. An expansion slot is a socket on a desktop or server motherboard that can hold an adapter card.

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.

MKA Chapter 5 : Digital Safety and Security

DIGITAL SAFETY AND SECURITY

Digital Security Risks

·         A digital security risk is any event or action that could cause a loss of or damage to a computer or mobile device hardware, software, data, information, or processing capability

·         Any illegal act involving the use of a computer or related devices generally is referred to as a computer crime; a cybercrime is an online or Internet-based illegal act.

·         Hacker will break the computer system with ethics to test the weakness of the system. But not damage the system or destroy data.

·         Cracker are deliberately breaks the system to bring damage and sabotage elements unethical, aggressive and dangerous.

Backing Up – The Ultimate Safeguard

·         A backup is a duplicate of a file, program, or media that can be used if the original is lost, damaged, or destroyed. To back up a file means to make a copy of it. Off-site backups are stored in a location separate from the computer or mobile device site.

Ethics and Society

·         Computer ethics are the moral guidelines that govern the use of computers, mobile devices, and information systems. Information accuracy is a concern, not all information on the web is correct.

·         Intellectual property refers to unique and original works such as ideas, inventions, art, writings, processes, company and product names, and logos.

·         Intellectual property rights are the rights to which creators are entitled to their work

·         A copyright protects any tangible form of expression.

·         Digital rights management (DRM) is a strategy designed to prevent illegal distribution of movies, music, and other digital content.

Information Privacy

·         Information privacy refers to the right of individuals and companies to deny or restrict the collection and use of information about them. Huge databases store data online. It is important to safeguard our information.

·         Content filtering is the process of restricting access to certain material on the Web. Many businesses use content filtering, web filtering software restricts access to specified websites