SMK MAMBAU

SMK MAMBAU

Sunday 1 April 2012

Computer Topics !!!

Get to know your PC

You need to be uninhibited if you want to learn more about using your PC. That's how kids learn to use them so quickly.
"Right-click" is one safe way to explore your PC. Right-click on anything and everything. Right-click means click an object with the right mouse button -- for example, this text -- try it and see what you get.

It's not going to hurt anything. It merely opens a context menu, which is simply a list of options appropriate for the object you right-clicked. Try clicking more objects up at the top of your browser.
Nothing happens until you "left-click" one of the menu options. If you're in doubt about clicking any of them, just left-click anywhere outside the menu and it will close. It's always safe to click "Properties", which gives you access to lots of information and settings.

Have a look around when "Properties" opens. There's always a "Cancel" button that will bail you out of "Properties" with no changes and no damage done. If you do make changes it could adversely affect your computer if you don't know what you're doing.

Start your computers.

Microsoft calls it "starting" your computer, but it's still "boot" to me. Don't confuse "starting" with the "Start" menu. Starting is turning on, starting , or booting your computer. The "bootstrap" method of loading the operating system into computer memory was invented about the same time electronic computers were invented.

I remember loading the first 17 "words" by hand to start one of the first computers I used. Each word was 2 bytes, or 16 bits. You had to set 16 switches and press the 17th to load each word. Using those 17 words (not switches), the computer was able to load another 1000 or so words on its own. They were on a strip of paper tape with holes punched in it -- much like a miniature player piano roll. Primed with those 1000 words, the computer was then able to load the rest of the operating system from a cassette tape.
It took me about 3 minutes to manually boot that old computer. Windows is loaded in a similar way. [more | more yet ] Too bad the process still takes so long, but there is a way to avoid booting your computer every day. The concept has been updated for Windows Vista.

Computing

The basic principles of general purpose computers have not changed since they were first conceived by Charles Babbage sometime before 1833. (His design was not actually built until sometime around 1990 -- yes those dates are correct.)

Computer principles don't change because they are as fundamental as mathematics, which of course don't change either. We're now close to the 60th anniversary of the first electronic computer, which was based on Babbage's original design. The big difference is they are powered by electricity, not steam.
Computer principles are embodied in the primary elements of a computer: input device(s), store (memory), processor, instructions and output device(s). In the beginning there were no hard drives, keyboards or monitors, much less mice. But they fundamentally worked in the same way.
Computer operation is straightforward -- data goes in (input) -- operations on the data are performed, results are stored (intermediate and final) -- the results come out (output). All of this is under the control of instructions (program), which are just another form of data.
For example -- [(2+4) divided by 3]. First the two numbers <2> and <4> are go in. They are added together and the temporary results are stored. The number <3> is then goes in. Next the temporary results <6> are divided by <3> and the results <2> come out. And it's all done in less than a millionth of a second.

The confusing thing about a PC is the multiplicity of input devices, memories, instruction sets, processors and output devices -- most of which are themselves used for multiple functions and tasks in turn. The keyboard, mouse, CD drives, modems and cameras are all input devices. Speakers, printers, the monitor, and modems (again) are common output devices.
Memory is used not only for data and results, but also for instructions. That's where it really gets confusing. The processor can't perform an instruction unless both the current data and the current instruction are in memory.

PCs work with much more data than memory can hold. That's why hard drives were invented. They "store" the data of the past (results), the data of the future (input), and instructions not currently being used. The processor goes to the hard drive to "fetch" data and instructions it needs next, and to "store" results it has completed.

Files

There are two primary types of files used by computers: instruction files and data files. Instruction files are either system (i.e., Windows) or program files. They instruct the processor to store input data, perform operations on the data, and output the results.
Data files may be in the form of documents, object files, data tables, output data or system data. Sound files and image files are examples of object files. Font files are an example of data table files. The "Registry" is the prime example of Windows system data.
All these file types -- data, system, and program -- are mixed together on the hard drive. They are segregated by location (folders) to a large extent, but it's somewhat of a mess. If you want to use a computer effectively, it's a big help to keep the files organized on your computer.
Windows Explorer is your window into the files on your computer. It gives you the big picture, yet you can zoom in and get things done quickly. There are some things you can't do any other way in fact.
Opening a file is a simple example of the efficiency of Windows Explorer. If you navigate to a file with Windows Explorer, a simple "double-click" will open the right program, which will then open the file. The other way is to open the program and then use it's less convenient navigation to open the file.

Backup

Backup is a chore, and people don't like to do chores. You're not likely take backup seriously until you've lost something irreplaceable -- maybe after it's happened twice. A wise person learns from the mistakes of other people though. Our backup pages should help you design and follow a backup strategy that fits your situation.

Computer myths

The most common PC myths are Windows myths. One of the most common is about how Windows uses memory. They persist because they seem logical. Most are relatively harmless, but they cause people to waste time, energy and money.

The virus myth: "You get a computer virus when you download a file to your hard drive". Truth is, not really. Yes, it's like a land mine -- harmless if left alone, but deadly if activated. If you open or install the infected file, the virus will be activated. But it can't do any harm until then.

The preview pane in Outlook Express (or Outlook) provides the grain of truth that perpetuates the download myth. Simply viewing an email in the preview pane can activate malevolent content (a virus or worm). Downloading the message caused no harm -- it's the preview pane that uncorks the content.

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