Quiz 7

Quiz 7 Communications and Networks

1. Discuss the components required for successful communications.

answer:

Sending device — initiates instruction to transmit data, instructions, or information
Communications device — connects the sending device to the communications channel
Communications channel — media on which data, instructions, or information travel
Communications device — connects the communications channel to the receiving device
 Receiving device — accepts transmission of data, instructions, or information

2. Identify various sending and receiving devices.

answer: 

A sending device initiates the transmission of data, instructions, and information while a receiving device accepts the items transmitted. All types of computers and mobile devices serve as sending and receiving devices in a communications system. This includes mainframe computers, servers, desktop computers, notebook computers, Tablet PCs, smart phones, portable media players, and GPS receivers.

3. Describe uses of computer communications.

answer:

Computers can be instructed to perform a variety of individual functions. A set of instructions that tells a computer what to do is called a program. Today, more than 10,000 application programs are available for use on personal computers. They include such popular programs as word processing programs, spreadsheet programs, database programs, and communication programs.
Word processing programs are used to type, correct, rearrange, or delete text in letters, memos, reports, and school assignments. Spreadsheet programs enable individuals to prepare tables easily. The users of such programs establish rules for handling large groups of numbers. For example, using a spreadsheet program, a person can enter some numbers into a table and the program will calculate and fill in the rest of the table.

Spreadsheets may be used for preparing budgets and financial plans, balancing a cheque book, or keeping track of personal investments.
Database programs allow a computer to store large amounts of data (information) in a systematic way. Such data might include the name, address, telephone number, salary, and starting date of every employee in a company. The computer could then be asked to produce a list of all employees who receive a certain salary.  

Communication programs connect a personal computer to other computers. People can thereby exchange information with one another via their personal computers. In addition, communication programs enable people to link their personal computers with databanks. Databanks are huge collections of information stored in large centralized computers. News, financial and travel information, and other data of interest to many users can be obtained from a databank.

4. List advantages of using a network.

answer:

• share software
• share information with others on networks
• share peripherals
• speed of sharing software and information files
• cheaper than buying individual software and hardware for each standalone especially if for a school, network software often offers deals for amount being purchased
• security, files can be copy inhibit mode
• centralized software management- software being loaded onto one computer but also this loads software to entire network at one time
• electronic mail(e-mail) between network users, ideal for office memos
• flexible access- access you files from any computer on the network unlike standalone which would mean only being able to access your data from the one computer you uploaded data onto.

5. Differentiate among client/server, peer-to-peer, and P2P networks.

answer:  
client - server model => One or more computers act as server and other computers or clients access server.

The client–server model of computing is a distributed application structure that partitions tasks or workloads between the providers of a resource or service, called servers, and service requesters, called clients. A server machine is a host that is running one or more server programs which share their resources with clients. A client does not share any of its resources, but requests a server's content or service function. 

peer - to - peer (P2P) => Simple network that connects fewer than 10 computers.Each computer, or peer, has equal capabilities.

Peer-to-peer (P2P) computing or networking is a distributed application architecture that partitions tasks or workloads between peers.Peers make a portion of their resources, such as processing power, disk storage or network bandwidth, directly available to other network participants, without the need for central coordination by servers or stable hosts. Peers are both suppliers and consumers of resources, in contrast to the traditional client–server model where only servers supply (send), and clients consume (receive).

6. Describe the various network communications standards.

answer:

Network communication standards are certain rules and specifications framed by standard organisations for manufacturing network hardware and developing network software.

7. Explain the purpose of communications software.

answer:
The purpose of communication software is used to provide remote access to systems and is also    used to exchange messages in text, audio and video format for the purpose of communication. This software sends and receives data over telephone lines through modems. The communication software allows computers in different geographical regions to communicate with each other through terminal emulators, file transfer programs, chat and instant messaging programs.

• Programs that help users establish connection to Internet, other network, or another computer.

• Programs that help users manage transmission of data, instruction, and information.

• Programs that provide an interface for users to communicate with one another.

8. Describe various types of lines for communications over the telephone network.
answer: 

A telephone network is a telecommunications network used for telephone calls between two or more parties.

There are a number of different types of telephone network:

• A fixed line network where the telephones must be directly wired into a single telephone exchange. This is known as the public switched telephone network or PSTN.
• A wireless network where the telephones are mobile and can move around anywhere within the coverage area.
• A private network where a closed group of telephones are connected primarily to each other and use a gateway to reach the outside world. This is usually used inside companies and call centres and is called a private branch exchange (PBX).

9. Describe commonly used communications devices.
answer:

• A dial-up modem converts digital signals to analog signals and vice versa
• Usually in the form of an adapter card

                                                     DSL Modem / ISDN Modem-Cable Modem

• Send and receive digital data from DSL(Digital Subscriber Line) / ISDN

         

                                                              Cable Modem

•  Sends and receives data over cable television (CATV) network
•  Much faster than dial-up modem or ISDN
•  Sometimes called a broadband modem

                                                                  Wireless Modem

• Allows access to the Web wirelessly from a notebook computer, a smart phone, or other mobile device. 

                                                                  Hub or Switch

• Device that provides central point for cables in network. 

                                                                       Router

• Connects computers and transmits data to correct destination on network.

10. Discuss different ways to set up a home network.
answer: 
 A home network can be enabled in a Windows XP system through various ways.In wired connections, the user can enable the home network option through the use of various physical media. The computers should be connected through wires with the help of a router. A wireless connection can be established without any physical medium and thus the user can stay at any position within the wireless range. For wireless connections, wireless-enabled devices are required to connect the system to the network. Configuring a Virtual Private Network is another method that is used to set up or access a home network. Home network connections can also be enabled through local area connections.

11. Identify various physical and wireless transmission media.

answer:

Physical Wireless transmission media  =>  Wire, cable and other tangible materials used to send communication signals.Used when inconvenient, impractical or impossible to install cables. It includes Bluetooth and IrDA.

Quiz 6

Quiz #6

1. Define system software and identify the two types of system software.

-  System software refers to the files and programs that make up your computer's operating system. System files include libraries of functions, system services, drivers for printers and other hardware, system preferences, and other configuration files. The programs that are part of the system software include assemblers, compilers, file management tools, system utilities, and debuggers. The system software is installed on your computer when you install your operating system. You can update the software by running programs such as "Windows Update" for Windows or "Software Update" for Mac OS X. 

       2 Types Of System Software

• Operating System
• Utility Program

2. Briefly describe various server operating systems: Windows Server, UNIX,Linux, Solaris, and NetWare.

- Windows Server is a brand name for a group of server operating systems released by Microsoft Corporation. 

- Unix  is amultitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie,Brian Kernighan, Douglas McIlroy, and Joe Ossanna. The Unix operating system was first developed in assembly language, but by 1973 had been almost entirely recoded inC, greatly facilitating its further development and porting to other hardware. Today's Unix systems are split into various branches, developed over time by AT&T as well as various commercial vendors and non-profit organizations. The second edition of Unix was released on December 6th, 1972.

- Linux refers to the family of Unix-like computer operating systems using the Linux kernel. Linux can be installed on a wide variety of computer hardware, ranging from mobile phones, tablet computers, routers and video game consoles, todesktop computers, mainframes and supercomputers. Linux is a leading serveroperating system, and runs the 10 fastest supercomputers in the world. The development of Linux is one of the most prominent examples of free and open source software collaboration; typically all the underlying source code can be used, freely modified, and redistributed, both commercially and non-commercially, by anyone under licenses such as the GNU General Public License. Typically Linux is packaged in a format known as a Linux distribution for desktop and server use. Some popular mainstream Linux distributions include Debian (and its derivatives such as Ubuntu),Fedora and openSUSE. Linux distributions include the Linux kernel, supportingutilities and libraries and usually a large amount of application software to fulfill the distribution's intended use.

- Solaris is a Unix operating system originally developed by Sun Microsystems. It superseded their earlier SunOS in 1993. Oracle Solaris, as it is now known, has been owned by Oracle Corporation since Oracle's acquisition of Sun in January 2010. Solaris is known for its scalability, especially on SPARC systems, and for originating many innovative features such as DTrace, ZFS and Time Slider.[3][4] Solaris supports SPARC-based and x86-based workstations and servers from Sun and other vendors, with efforts underway to port to additional platforms. Solaris is registered as compliant with the Single Unix Specification.

- NetWare is a network operating system developed by Novell, Inc. It initially usedcooperative multitasking to run various services on a personal computer, with network protocols based on the archetypal Xerox Network Systems stack.

3. Summarize the features of several embedded operating systems: Windows Embedded CE, Windows Mobile, Palm OS, iPhone OS, BlackBerry, Google Android, Embedded Linux, and Symbian OS.

- Microsoft Windows CE  is an operating system developed by Microsoft for embedded systems. Windows CE is a distinct operating system andkernel, rather than a trimmed-down version of desktop Windows. Windows CE is optimized for devices that have minimal storage—a Windows CE kernel may run in under a megabyte of memory. Devices are often configured without disk storage, and may be configured as a “closed” system that does not allow for end-user extension (for instance, it can be burned into ROM). Windows CE conforms to the definition of a real-time operating system, with a deterministic interrupt latency. From version 3 and onward, the system supports 256 priority levels and uses priority inheritance for dealing with priority inversion. The fundamental unit of execution is the thread. This helps to simplify the interface and improve execution time.

- Features Windows Mobile

• Today screen shows the current date, owner information, upcoming appointments, e-mail messages, and tasks. (Home screen in later WM6.5 builds)
• The taskbar shows the current time and the audio volume.
• Office Mobile, a suite of Mobile versions of Microsoft Office applications, including Outlook Mobile.
• Internet Explorer Mobile, an Internet browser developed by Microsoft for Pocket PC and Handheld PC that comes loaded by default with Windows Mobile and Windows CE for Handheld PC.
• Windows Media Player for Windows Mobile.
• Client for PPTP VPNs.
• Internet Connection Sharing (ICS), which in mobile phones allows the phone to make its Internet connection available to computers via USB and Bluetooth.
• File system similar to that of Windows 9x/Windows NT, with support for many of the same file types.
• Ability to multitask.

- Palm OS  is designed for ease of use with a touchscreen-based graphical user interface.

Features:

• Simple, single-tasking environment to allow launching of full screen applications with a basic, common GUI set
• Monochrome or color screens with resolutions up to 480x320 pixel
• Handwriting recognition input system called Graffiti 2
• HotSync technology for data synchronization with desktop computers
• Sound playback and record capabilities
• Simple security model: Device can be locked by password, arbitrary application records can be made private
• TCP/IP network access
• Serial port/USB, infrared, Bluetooth and Wi-Fi connections
• Expansion memory card support
• Defined standard data format for personal information management applications to store calendar, address, task and note entries, accessible by third-party applications.

- iPhone OS Features:

• Multitasking
• Fast App Switching
• Local Notification
• App Folders
• New App E-mail
• iBooks

- Blackberry Features:

• Multi-touch Interface
• Webkit Browser
• Home Screen
• Universal Search
• Context Sensitive Menus
• Social Tools

Google Android Features:

• Handset layouts
• Storage
• Connectivity
• Messaging
• Multiple language support
• Web browser
• Java support
• Media support
• Streaming media support
• Additional hardware support
• Multi-touch
• Bluetooth
• Video calling
• Multitasking
• Tethering
• Screen Capture

4. Explain the purpose of several utility programs: file manager, search utility, image viewer, uninstaller, disk cleanup, disk defragmenter, backup and restore utilities, screen saver,

 personal firewall, antivirus programs, spyware and adware removers, Internet filters, file compression, media player, disc burning, and personal computer maintenance.

• File Manager - is a computer program that provides a user interface to work with file systems. The most common operations performed on files or groups of files are: create, open, edit, view, print, play, rename, move, copy, delete, search/find, and modify attributes, properties and permissions.
• Image Viewer - is a computer program that can display stored graphical image; it can often handle various graphics file formats.
• Uninstaller - also called a deinstaller, is a utility software designed to remove other software or parts of it from a computer. It is the opposite of an installer.
• Disk cleanup - is a computer maintenance utility included in Microsoft Windows designed to free up disk space on a computer's hard drive. The utility first searches and analyzes the hard drive for files that are no longer of any use, and then removes the unnecessary files. 
• Disk defragmenter - is a process that reduces the amount of fragmentation in file systems. It does this by physically organizing the contents of the mass storage device to store files in a contiguous region if possible, or in the smallest possible number of regions (fragments) if not. It also attempts to create larger regions of free space using compaction to impede the return of fragmentation. Some defragmenters also try to keep smaller files within a single directory together, as they are often accessed in sequence.
• Backup Utility - allows users to copy files to another storage medium.
• Restore Utility - reverses the process and returns backed up files to their original form
• Screen Saver - causes a display device’s screen to show a moving image or blank screen if no activity occurs for a specified time
• Personal Firewall - detects and protects a personal computer from unauthorized intrusions
• Anti Virus Program - protects a computer against viruses
• Spyware removers - detects and deletes spyware and other similar programs
• Adware remover-  is a program that detects and deletes adware
• Internet Filters - are programs that remove or block certain items from being displayed
• File Compression - shrinks the size of a file(s), compressing files frees up room on the storage media.
• Media Player - allows you to view images and animation, listen to audio, and watch video files on your computer
• Disc Burning - writes text, graphics, audio, and video files on a recordable or rewritable optical disc.
• Personal Computer Maintenance - identifies and fixes operating system problems, detects and repairs disk problems, and includes the capability of improving a computer’s performance

Quiz 5-Storage

1. Differentiate between storage devices and storage media.

answer:

Storage device refers to the apparatus for recording computer data. Examples are the RAM, floppy drives, ZIP drives, and other disks drives. While, storage media are the materials on which data are written and stored. Examples are the floppy disks, optical discs, hard disks, etc.

2. Identify the uses of tape, magnetic stripe cards, smart cards, microfilm and microfiche, and enterprise storage.

answer:

Tape is a magnetically coated ribbon of plastic capable of storing large amounts of data and information at a low cost. A tape drive reads and writes data and information on tape. Business users utilize tape most often for long-term storage and backup. A magnetic stripe card is a credit card, entertainment card, bank card, or other similar card with a stripe that contains information identifying you and the card. A magnetic stripe card reader reads the information stored on the stripe. A smart card, which is similar in size to a credit or ATM card, stores data on a thin microprocessor embedded in the card. A smart card reader reads the information on the smart card and updates it if necessary. Microfilm is a 100- to 215-foot roll of film. Microfiche is a small sheet of film, usually about 4 X 6 inches. Microfilm and microfiche reduce the amount of paper firms must handle, are inexpensive, and have the longest life of any storage media. Enterprise storage use computers, servers, and networks to manage and store huge volumes of data and information. In an enterprise, some storage systems can provide more than 185 TB of storage, and optical disc servers hold hundreds of optical discs.

3. Describe the various types of flash memory storage: solid state drives, memory cards, USB flash drives, and ExpressCard modules.

answer:

Flash memory storage are a type of solid state media, which means they consist entirely of electronic components and contain no moving parts. A solid state drive (SSD) typically uses flash memory to store data, instructions, and information. A memory card is a removable flash memory device that you insert and remove from a slot in a computer, mobile device, or card reader/writer. Common memory cards include CompactFlash (CF), Secure Digital (SD), Secure Digital High Capacity (SDHC), microSD, microSDHC, xD Picture Card, Memory Stick, and Memory Stick Micro (M2). A USB flash drive, sometimes called a thumb drive, is a flash memory storage device that plugs in a port on a computer or mobile device. An ExpressCard module is a removable device that fits in an ExpressCard slot. Express Card modules can add memory, storage, communications, or other capabilities to a computer.

4. Differentiate among various types of optical discs: CDs, archive discs and Picture CDs, DVDs, and Blu-ray Discs.

answer:

A CD-ROM, or compact disc read-only memory, is a type of optical disc that uses laser technology to store items. Users can read the contents of standard CD-ROMs but cannot erase or modify their contents. A CD-R (compact disc-recordable) is a multisession disc on which users can record their own items, such as text, graphics, and audio. Each part of a CD-R can be written on only one time, and the disc's contents cannot be erased. A CD-RW (compact disc-rewritable) is an erasable disc that can be written on multiple times. An archive disc stores photos from an online photo center in the jpg file format. A Picture CD is a single-session CD-ROM that stores digital versions of film using the jpg format at a lower resolution than an archive disc. A DVD-ROM (digital versatile disc-read-only memory or digital video disc-read-only memory) is a high capacity optical disc that you can read but not write on or erase. A newer, more expensive DVD format is Blu-ray Disc-ROM (BD-ROM), with higher capacity and better quality than standard DVDs. Many types of recordable and rewritable DVD formats are available. DVD-R and DVD+R are DVD-recordable formats. BD-R is a high-capacity DVD-recordable format. DVD-RW, DVD+RW, and DVD+RAM are rewritable DVD formats that allow users to erase and record multiple times. BD-RE is a high-capacity rewritable DVD format.

5. Summarize the characteristics of ink-jet printers, photo printers, laser printers, multifunction peripherals, thermal printers, mobile printers, label and postage printers, and plotters and large-format printers.

answer :

An inkjet printer is a type of computer printer that creates a digital image by propelling droplets of ink onto paper. Inkjet printers are the most commonly used type of printer.

Laser printers operate by shining a laser beam to produce an image on a drum. The drum is then rolled through a pool, or reservoir, or toner, and the electrically charged portions of the drum pick up ink. Finally, using a combination of heat and pressure, the ink on the drum is transferred onto the page. Laser printers print  very fast, and the supply cartridges work a long time. Color laser printers use the same toner-based printing process as black and white ( B/W) laser printers, except that they combine four different toner colors.  Color laser printers can also be used as a regular black and white laser printer. 

Multifunction printers: combine top-quality color ink-jet or laser printing with plain-paper and PC faxing, color copying and color scanning , telephoning- all in one convenient, space-saving machine. If you work from home or have a small office a multifunctional device may be ideal. 

Label Printers are  the smartest way to print labels one at a time.  The printers allow easy installation.  You can  get high-quality, professional results every time. There are multi-purpose  printers , that can print different types of labels. For example, label printers used in supermarkets can print bar codes as well as normal text. There are also some label printers that can print different sizes of labels on goods.

Plotters  (Designjet) are large-scale printers that are very accurate at reproducing line drawings. They are commonly used for technical drawings such as engineering drawings or architectural blueprints. The two basic types of plotters are called flatbed plotters and drum plotters. Flatbed plotters are horizontally aligned with a flat surface to which a piece of paper is attached. The paper remains stationary and the printer moves pens across the paper to draw the image. Drum plotters, also called upright plotters, are vertically positioned. They have a drum that the paper rolls on. Drum plotters usually make more noise and are more compact than flatbed plotters. 

Portable printers are usually fairly lightweight and sometimes carry the option of using a battery instead of drawing power from the computer. Usually they realize basic print resolutions suitable for plain text printing. You can find on the market the following types of the portable printers:  Thermal printer, Thermal transfer printer and Ink-Jet printer. The main advantage of thermal and thermal transfer printers is that they can be very small. The smallest thermal and  thermal transfer printers  weigh  approximately one pound. Usually the  ink-jet portable printer weighs more than 2 pounds. Thermal printers require a special type of paper.

Quiz 3

Quiz 3

1. Describe the four categories of output.

1. Monitors

   •  Flat-screen monitors are more energy efficient than cathode ray-tube monitors. Monitor image by Kavita from Fotolia.com
     

     There are two major categories of monitors: Cathode ray-tube or CRT and liquid crystal display, also known as flat-screen or LCD. Both measure screen size diagonally and connect to the computer via USB port or a conventional printer cord. The flat-screen monitor uses up less power and causes less eye strain.

   Speakers and Headphones

   •  Headphones are used to turn your computer into a telephone, stereo, or video game. 
     

     Part of the sound card system that produces multimedia, speakers and headphones produce audio output. The range of audio equipment available to the average computer user is tailored to Skype users, gamers, movie and video enthusiasts, and musicians. Most headphones also include a microphone for input as well.

   Printers

   • Modern printers are advanced enough to publish detailed graphic arts and photos. 
     

     Printers are used to make hard copies of computer output. There are three different kinds of printers. Dot matrix is the oldest and since it is slow and rather noisy compared to laser and ink-jet printers it is no longer widely used. Laser printers are the most expensive, but are fast and quiet and Ink jet printers are inexpensive to buy, but the paper and toner consumption makes up for the cheap retail price.

   Disks and External Drives

   •  Portable memory sticks may have rendered CDs obsolete as output devices. 
     

     CDs (which include rewritable CDs, DVDs, floppy disks and external hard drives are used as storage devices for data output. Data can be text, video, audio or graphics files. External memory drives are often portable depending on the size. Both disk drives and CDs can also be used as input devices.

 
2. The characteristics of LCD monitors, LCD screens, plasma monitors, and HDTVs.

• LCD Monitor- ultra-slim, stylish,full color display devices for the PC that fit in any part of the home or office.
• LCD Screens- lightweight, aesthetically appealing, energy efficient and long-term cost effective. 
• Plasma Monitors- produce rich colors along with very deep blacks,wide viewing angles allow more people to be able to watch TV comfortably, pixels of Plasma TV’s are lit individually so the pixels can be completely turned off to display truck black colors. 
• HDTVs- black level, brightness, contrast, color saturation, image processing, screen composition, tuners and cable card.

3. What are the components inside the systems units.

• Processor
• memory
• adapter cards
• ports
• drive bays
• power supply
• motherboard
• chip
• Central Processing Unit
• Machine Cycle 

4. The components of a processor and how they complete a machine cycle.

• Control Unit
• Arithmetic/ Logic Unit (ALU)
• Register

 The machine cycle is the name of the four operations of the CPU. The first step is to 'fetch' the program instuction/data from the memory. The second step is to 'decode', which means translate the instruction into instructions. Step three is to 'execute', carry out the instruction. Finally step four is to 'store', write the result back to memory.

5. Define a bit and describe how a series of bits represents data.

When the user press any letter using the keyboard the electronic signal from that letter is sent to the system unit then the system unit convert it to its binary code and stored in memory for processing. After processing the binary code for that particular letter is converted to an image and displayed on the output device.

6.Categories of Application Software:

• Personal productivity Applications
• Multimedia and Graphics applications
• Communications applications 
• Home and Educational

7.  The Key Features in Business programs in terms of software is editting and typing and other stuff knowing what letters to use like formating.

8.  What are the advantages of using application software on the Web.

Using web authoring software can help build web pages faster, an advantage if you are facing a deadline or a large project. There are several different types of web authoring software you can use to make great web pages without having to know all of the ins and outs of web page creation.

9. History of the Internet.

 The USSR launches Sputnik, the first artificial earth satellite. In response, the United States forms the Advanced Research Projects Agency (ARPA) within the Department of Defense (DoD) to establish US lead in science and technology applicable to the military.

RAND Paul Baran, of the RAND Corporation (a government agency), was commissioned by the U.S. Air Force to do a study on how it could maintain its command and control over its missiles and bombers, after a nuclear attack. This was to be a military research network that could survive a nuclear strike, decentralized so that if any locations (cities) in the U.S. were attacked, the military could still have control of nuclear arms for a counter-attack.