Operating system (OS)

                                             Week 6

 Operating system (OS)

in this week we had a debate on explaining how between wired internet connection and wireless which one is better.i was supporting wireless is better reason being wireless facilitate mobility means that you can access internet on the go for instance mobile we use everyday can be a good example.the debate ended in 30 minutes and my side won one of the example that made us win this debate is this example given by one student:-if there was no wireless people to make a call there should need long cables. this was the point that was not easy to answer for the opponent group.

after debate we studied week five lesson:Operating system

Microsoft released a number of Windows operating systems ranging from Windows xx, NT, Server from 1985 till now. The latest is Windows 8. Microsoft created the operating system, Windows, in the mid-1980s. They have a version of the operating system that is designed for the home user, and a professional version, which is intended for businesses. The versions differ in the depth of networking, security, and multimedia support.

Windows is proprietary software, which means that Microsoft has placed restrictions on how people can use or copy the software. Windows comes preloaded on most of the PCs sold today, and can also be purchased separately.

Windows aims.

                                       Decrease Start Up and Shutdown times by 20 secs

                                       Go to Sleep and Resume faster

                                       Use up less Memory

                                       Pop up Search results faster

                                       Reconnect to your Wireless Network more quickly

                                       Recognize USB devices faster

Windows 7 also saves time by not booting up various devices during Start Up unless they are currently being used. In other words, if you are not using a Bluetooth device at the moment then Windows 7 will not waste time by running that program in the background. It will wait until you have plugged it in. However, performance tests of Windows 7 indicate that actual improvements vary and greatly depend on the conditions of your specific computer and the programs you are running. We will go into more detail regarding your computer's ability to run Windows 7 in future lessons
We’ve seen that windows seven has new upgrades from vista and Xp such as :

• New Taskbar and System Tray
• Quick Desktop View button
• Improved Start Up, Sleep and Resume performance
• Improved power management saves memory and battery life
• Libraries to improve file access and organization
• Action Center for system maintenance, backups, troubleshooting and more
• User Account customization of notifications
• Improved back up
• New wallpapers and themes
• Improved Gadgets
• New premium games include Chess Titans, Mahjong Titans and Inkball
• Advanced Calculator functions including saving history
• Improved networking via HomeGroups
• Passkey protection with networks
• Device Stage for recognizing USB devices faster
• Windows Mail replaced by Windows Live

                                        Anatomy of windows 7

1.Aero view

2.Taskbar  
3.Search
4.Libraries
5.Gadgets

Windows7 File Management

The Windows 7 environment is not an extension of XP; it’s an entirely new interface. Although the underlying file structure is the same, there’s less to file management compare to XP. Windows 7 doesn’t require the knowledge of storing and accessing files as in XP and earlier versions — the file hierarchy is behind the scenes. Windows 7 is in fact easier to use, but you need to be acquainted with it.

Finding Files and Folders

Most users access their files through "My Documents", the "C" drive, or from other locations like a server or back up drive. You are likely accustomed to sorting through tiered stacks of folders to get to your content. This process can be time consuming, especially if you cannot remember where an item is filed. Microsoft wanted to make "finding your stuff" easier, so they developed Libraries.

   

Libraries are collections of your stored content that can be easily accessed through the Desktop Search function. Libraries do not replace your folders, they simply house them in a single collection.

When files are placed in a Library, their properties are indexed by the Search function. This indexing makes accessing files in Search quick and easy.

A New Approach to Accessing Content

Libraries have automatic default save folders. Unless specified, your content will be saved in the default folder of the Library it matches.You can change the default save folder by selecting Locations in the Tool Bar.You are not required to save or access your content through Libraries. The Navigation pane gives you access to Computer where your folders and drives are stored. You may still sort through the tiered stacks of folders in the classic way to save and access content.

Computer Network

                                              WEEK 4

 Computer Network

It is simply a group of interconnected computers.Two or more computers are connected via hardware or software, and able to communicate with each other.

The computers of a network may be located nearby to each other or at different geographic locations.Example of a computer network:

the Internet, ATM, school network, e-banking, home network, etc.

well the computer network is quit import we use it in our everyday routines you know! ressources sharing information sharing and ofcourse emailing.

now let see what opponents that are required to computer network.first and first Communication Media,Interconnecting Devices,Computers,Applications and finally Networking Software.

Every computer Networking must have these three concepts which are Topology(the physical layout of the network).Protocol (the rules in data communication)and

Architecture(how the hardware and software are integrated to form a working.)

A computer network involves communicating data between computers.Three elements at least must exist:

Sender,medium and receiver

we've also learned some characteristics data  transmission,the first one is analog  transmission the data are transmitted in form of continuous waves transmitted over a medium at a certain frequency rage,

the rate of transmission is called bandwitch. The other sort of  transmission is Digital transmission: sends data in the form of bits.sorted by signal.

ordered by bits there is serial and parallel;series one bit is sent after another,but parallel all bit are sent at once a long multiple paths.

again Bandwidth is the range that a medium can correctly transmit data.The rate at which the signal changes is known as Baud

Some type of link through which the data can be transmitted or transferred from one computer to another. To send data through the channel requires some type of transmission media, which may be either physical or wireless.

Computers share access to common network medium that carries signals from one computer to another. Medium may be physical cable, such as twisted pair, coaxial, or fiber-optic. Medium may also be wireless. Physical interface to medium is usually network interface card (NIC) or network adapter. Kind of medium dictates type of connector and limits number and type of devices as well as distance a single LAN can span

Twisted-pair cable – consists of two independently insulated wires twisted around each other (least expensive type of cable—the kind that is used in many telephone systems)

Coaxial cable – consists of an insulated center wire grounded by a shield of braided wire (the primary type of cabling used by the cable television industry;  it is more expensive than twisted pair)

Fiber-optic cable – contains hundreds of clear fiberglass or plastic fibers (threads) (made from thin, flexible glass tubing; bandwidth is greater, so it can carry more data; it is lighter than metal wires and is less susceptible to interference; it is fragile and expensive)

ISDN line – a special digital telephone line that transmits and receives information at very high speeds

                                                Wireless Media

Also known as unguided medium.

Microwave system – transmits data via high-frequency radio signals through the atmosphere.Satellite system – receive transmitted signals, amplify them, and then transmit the signals to the appropriate locations Cellular technology – uses antennae resembling telephone towers to pick up radio signals within a specific area (cell)Infrared technology – transmits data as infrared light waves from one device to another, providing wireless links between PCs and peripherals

Digital Communication

Communication has changed radically in today’s digital age and our lifestyle.Today, we are talking about digital communication, digital entertainment, digital mobility and so forth.It’s already happening accessing home computer from our cell phone. This is the era of digital telephony.

Challenging question J :

Can you describe the communication medium involved in digital telephony?

                                       Wireless Networking : Wi-Fi

•Wi-Fi is an abbreviation for Wireless Fidelity and a catch all phrase for the several different standards and recommendations that comprise wireless networking. 

–IEEE 802.11.b –2.4GHz – 11Mbps

–IEEE 802.11.a – 5GHz – 54 Mbps

–IEEE 802.11g – 2.4Ghz – Hybrid 11/54Mbps 

•Wi-Fi enables the user to deploy a computer network without needing to run cable throughout the facility.

•Microwave ovens, cordless phones, medical and scientific equipment, as well as Bluetooth devices, all work within the 2.4 GHz frequency band.

  

Application-Any application currently used on a traditional wired network can be used on a                                  wireless network. New applications may be available or can be developped to 
                                 take advantage of wireless, such as Wireless PDA access to a card catalog.

However, Wi-Fi has limitations such as:

–The effective coverage is 300-1400ft. from access point

–Structural interference

–Interference from other devices such as cordless phones.

this the end of this week, andIi guess you are enjoning this lesson  i ll see you nest week chao!