The Clipboard

* CUT will save your selection on the clipboard, and erase the original. This is useful when you want to move something from one place to another.
* COPY will save your selection to the Clipboard, but it will not erase the original. This is useful when you want to make extra copies of something in a new place.
* PASTE will take something that you cut or copied, and put it into the new place. You can PASTE something as many times as you like.

After CUT or COPY, the thing you saved will stay on the clipboard as long as the computer is on. It will only disappear when you turn off the computer, or when you CUT or COPY a new thing into the Clipboard. The Clipboard can usually only remember ONE THING at a time (although some applications add extra clipboard spaces which you can use).

Next is Desktop, in which you can select a Desktop "wallpaper." PLEASE do not change the wallpapers in the media center or LCJ labs!!!

The next is the Screen Saver. This feature was most used with the old TV-style CRT monitors, because if the screen stayed the same, the screen image would literally burn into the monitor and make a permanent "ghost" image. On newer LCD screens, this is not so much a problem; while burn-in can happen with LCD screens, they usually can "heal" and the burned image disappers after the monitor "rests" wile turned off for a while.

However, many see screen savers as fun or interesting. They can also be for security, requiring a password to stop the screen saver.

Next is Appearance, where you can set window colors and text sizes.

Finally, there is the most useful tab: Settings. Here, you can change the monitor's color and resolution. Advanced features include Hertz settings, if screen flicker is hurting your eyes (60 Hertz should work best). BE CAREFUL: on some older computers and monitors, changing the Resolution settings can result in a black screen which can be hard to switch back from! If you change the resolution and the screen goes black, just leave it and don't touch the keyboard or mouse. If you're lucky, the screen will snap back to the original settings within 15 seconds.

Make sure to choose the yellow folder, titled "Open writable CD folder using Windows Explorer." Then click "OK," and you should see this window appear:

If you add files or folders to this window, they will appear like the files you see pictured above. They will be gray, and will have arrows pointing down in the icon (like the "Shortcut" icon arrow, but slightly different).

Notice the "CD Writing Tasks" area, shown by the top red arrow. This will allow you to delete files you put into this folder, or to permanently write them onto the CD.

Once you have added all the files you wish, then click on the "Write these files to CD" link. Windows will then write these files onto your blank CD.

Most new software will write in what is called "Session Mode." In the past, if you wrote something onto a CD, even just a small amount, the disk could never again have anything more written onto it. But today's software uses something called "Session Mode," which allows you to add more and more items to the CD-R whenever you like, until the CD is full.

If you do not have Windows XP, you must get special software to burn optical disks. Deep Burner is an example of a freeware program, which should make burning CDs easier even with XP or Vista. A free Mac program for burning CDs or DVDs would be "Burn." Easy Media Creator (called "Toast" for Macintosh) is a popular commercial program. These programs also allow you to use advanced options, and you can make special disks (including Music CDs, Video DVDs, and so on).

The first step is to move the file(s) to the Recycle Bin, located on the Desktop. The Recycle Bin is really just a folder. When you throw a file into the Recycle Bin, it is not erased. Files will stay there until you erase them; that is the next step.

To really get rid of a file, you must Empty the Recycle Bin. You can do this by right-clicking on the Recycle Bin and selecting "Empty Recycle Bin." (You can also open the Recycle Bin window and choose "Empty" from the Task Management Area.) When you do this, the files will be erased.

It is a good idea to erase unused or unwanted files. That will prevent your computer from becoming cluttered, and will free up space on your storage in case it gets full.

Actually, the files are not really erased when you empty the Recycle Bin. In truth, the files are still there, on the storage device. What really happened is that your computer erased its knowledge of the location of the files, and so sees that part of the storage as "empty." However, the data for the file is still there on the storage device. With special software, you could still go back and get the files.

So when do the files really get erased? That happens when the computer, by chance, saves new files in the same location that the old ones were saved at. When that is done, the old files are truly, completely, erased.

Some computers and software allow you to do a "super erase" or "secure erase." This special erase action will not just erase the knowledge of the location of the files. It will actually write blank information on top of the old location of the files. In fact, some kinds of "super erase" will write over the erased location seven or eight times, just in case. This is done for security reasons, so no one can retrieve the data and steal it.

Computer Networks

The computer networks we use today were created in the late 1960's to early 1970's. The U.S. government had many large computers all across the country, and most used different and sometimes unique operating systems; therefore, they could not communicate with each other. The military wanted to (a) allow the computers to "speak" to each other so they could increase the speed of research and data transfer, and (b) create a non-centralized communications network which would allow the military to communicate in times of war.

The Defense Advanced Research Project Agency (DARPA) engineers created protocols to achieve this. A "protocol" is a universal language and/or set of rules, that all computers share and agree on. You use protocols every day. The rules about when and how much to bow to others is a protocol--there are rules about bowing which everybody understands and follows. You can find protocols everywhere: the location of light switches near a door follow protocols; the counting of hours and days follows protocols; which way doors open follow protocols; how people drive cars follows protocols; and so on. Without protocols, we would have trouble doing almost anything in a coordinated way. But computer networks especially rely on protocols.

Network activities, including on the Internet, use protocols. For example, HTTP is the Hyper Text Transfer Protocol. POP, used for e-mail, is Post Office Protocol. FTP, for moving files over the Internet, is File Transfer Protocol. And the main protocol for computers to connect with each other is called TCP/IP, or Transmission Control Protocol/Internet Protocol.

Because of protocols like TCP/IP, all computers can now communicate and form networks. That ability allows us to have everything from the Internet to small local-area networks like the ones you see in our computer labs.

Most computer networks use wires to connect to each other. These are usually Ethernet cables. Ethernet is the standard networking system. Ethernet cables are so common that they are commonly called just LAN cables or Network cables.

Most computers have only one Ethernet port (the place where you plug a cable in). If you connect only two computers, you can do it with one cable. However, to connect more than two devices--which is the usual case--you must use an Ethernet hub. This is a box with 4, 8, 16, or some other number of ports, all connected. You just plug in the cable leading to the network source, then plug in computers to the rest of the ports.

If you have too many computers for one hub, just add another hub to one of the cables. You can add more and more hubs as needed.

Not just computers can connect to networks; also printers, hard disk drives, cameras, and cell phones can be part of a network.

Another kind of network technology is called WiFi, or Wireless. WiFi uses radio signals to send data. You only need a cable from the Internet to the WiFi base station. After that, everything is done without cables. Many people use this for convenience, especially if cables cannot be going across the floor all the time.

WiFi comes in four different types: a, b, g, and n. "b" is the slowest; "a" and "g" are medium speed; "n" is the fastest.

There are different types of networks based upon location. Thw two main types are Local Area Networks (LAN) and Wide Area Networks (WAN).

A LAN is a network in a single building, or even in a single room. The computer lab you are using at LCJ has a LAN; this is how we can all see the same network hard drive.

A WAN is a network between buildings. It could be two buildings close to each other, or a million buildings all over the world. The Internet is the world's biggest WAN.

There are special computers which act as connectors between computer networks; these are called servers. A server controls networks, and serve as conduits which pass data from one LAN to another.

In order for computers to send information to each other, each computer must have an address. This is called an IP Address, and usually consists of 4 numbers connected by dots, each number being between 0 and 255. For example, 63.184.5.201 could be an IP address.

There are two kinds of IP addresses: external and internal. These are like apartment addresses: there is a main address for the whole building, and then each apartment has a special number. The same is true for networks: the external IP address is for the server connecting to the Internet, and then each computer has a special number, an internal IP address.

Internal IP addresses are similar to apartment numbers in another way: they usually have the same pattern. With apartments, you start with the floor number and then the room number; for example, you would know that apartment 2307 is the 7th apartment on the 23rd floor. Most internal IP addresses begin with 192.168.1 and then the last number is the computer number.

Take a look at the IP addresses for my home computer:

The external IP address is 121.129.52.13; that's the IP address for the general local network. This is the IP address other people on the Internet can see.

The Internal IP address is 192.168.1.5; that's the IP address for my laptop computer. That's internal and private; nobody outside my apartment can see it.

You can find your computer's IP address by going to the Network Connections control panel, opening the first "Local Area Connection" icon, and clicking on the "Support" tab. (On a Mac, go to System Preferences, click on Network, Built-in Ethernet, and then TCP/IP.)

Recently, most LANs use a simple way to get an IP address. It is called DHCP. With DHCP, your computer will automatically get an IP address any time you plug in the network cable. You don't have to do anything. Without DHCP, you must carefully type in an IP address and other information that the network manager gives you.

If you want to see other computers on your network, go to the Start Menu and open My Network Places. If the folder you are looking for is not there, then you can either look for it by clicking "View Workgroup Computers" in the task management area, or you can add the place permanently to "My Network Places" by clicking "Add a Network Place" in the task management area, and choosing the folder you want to add.

In order for a folder to appear in everyone's "My Network Places" folder, it must be Shared. To share folders, a computer must be set up for sharing by running the Network Setup Wizard. Once the computer has been set up, just right-click on a folder and select "Sharing and Security." Select the "Sharing" tab, and click "Share this folder on the network."