How Computers Work

A computer is a fascinating machine that is made up of many different parts. It is an electronic machine that can perform calculations and can process a large amount of information accurately and much more rapidly than the human brain.

There are two basic kinds of computers. P. C.'s and Macintoshs. "PC's" or Personal Computers which include Compaqs, Hewlett-Packards, Dells, and Gateways.

Macintoshs or "Macs," are made by the Apple Corporation. You will learn more about both of these types of machines when we study Computer History later in the semester.

You've probably seen these two guys on TV commericals.

Both types of computers do basically the same things, but many people prefer one to the other. The computers you'll be working with in this class are Macs.

The two most popular types of computers are laptops, like the one below,

and desktops, like these.

Again, both do about the same thing, but the laptop is portable and can go about anywhere you do.

The Central Processing Unit or CPU is the “brain”

or “heart” of the computer. It receives information and processes output. The CPU is also referred to as the microprocessor. It has two parts: the control unit or “traffic cop” and the Arithmetic Logic Unit or ALU. The ALU performs the computer’s logic functions.

 

The black and colored objects inside the CPU, under the lid of the computer are called chips. Chips are made of silicon, a very hard plastic. It is the second most common element on earth besides . They are usually about an inch in diameter and wafer thin.An integrated circuit is a tiny but complete electronic circuit. These are also called ICs. ICs may contain thousands of transistors and other electronic components.The microprocessor is one of the most important chips inside the computer. It’s basic function is to process data then produce output.
                                           

A computer uses information much like a person does. It receives information from input devices, such as the keyboard, mouse, or a microphone, much as we read and hear information.

It processes the information just as our minds decode words and pictures. Then it gives output on its monitor or from its speakers the same way we write and speak to give output.

Another term you will hear when learning about computers is hardware. We’re not talking about hammers and nails here, we’re talking about the physical equipment of the computer. Hardware is divided into two sections, input devices and output devices, a few mentioned already in this chapter. Input devices are your keyboard, your mouse, the computer’s microphone if it has one, and a scanner. Output devices are speakers, your monitor, and the printer.

Here’s a little more about the input device called the scanner which we talked about before. A device that converts art, photography, or other graphic material into bit- mapped data that is input into the computer. These digitized images can be edited by a computer graphics artist.

CRT stands for Cathode Ray Tube. Another name for CRT is monitor. A computer monitor is different than a television because it has no receiver.
                                                                                 

When people talk about buying a new computer, many times they’ll say they’re going to buy a new “system.” What they mean by this is that they’re buying a group of similar devices that work together as a team.

A menu on a computer is a lot like a menu in a restaurant. It is a list of options from which a program user can choose in order to give a command to the computer. Selecting a menu item gives the computer a specific command. A window is a portion of the computer screen that can contain its own documents.

ASCII stands for American Standard Code for Information Interchange. It’s kind of like a worldwide language that all computers comprehend and speak. The computer uses a number system based on one and zero. This is called the Binary Number System and is different from our usual base ten system. These digits are better known at "bits."

                                                                       
A word processor is software that allows a you to type a paper, a letter, or a story for example. One of the useful things you can do on a word processor that you can’t do with pencil and paper is using a spell checker to make sure your words are correct. This is part of a word- processing program that uses a disk- based dictionary to check for and correct misspelling in documents. It also helps you count your words. There are also thesauruses and grammar checkers in some programs. Examples of word processing programs are Microsoft Word, Word Perfect, and AppleWorks.

You will learn some new words while working with a word processor. For example, a document is anything that is produced using a word-processing program. To edit a document is to make any change to the contents of a document. This means to correct something. For example, if you hand in a paper to your teacher, she makes corrections, and you rewrite the paper, you are editing. Editing is much easier to do on a computer.

For example, to add information in the middle of existing text is easy. To do this is called to insert. This means if you have two paragraphs typed and want to add one in the middle, you just click there and start typing. That’s how you insert. Delete means erase or remove words from a page, or a document from your computer. This is also a key on the computer keyboard.

At very high speeds, computers take this inputted information and sends it to specific places so that special jobs or functions can take place. When learning to use a computer, you may hear the work “data” used frequently. Data is a general term for pieces of information that a computer processes.

                                                                               

       
You can always Save or store information on your computer, on what is called the hard drive or hard disk. The hard disk can store more data and is a part of the computer. Many computers today, such as the iMac and eMac, have their hard drives built right into the rest of the computer.

                                                                                                     
You can also use other storage devices that let you take your work with you. These are called secondary storage devices. Older computers used floppy disks. These are called “floppies” because although they are incased in a hard plastic shell, they are actually made from the same magnetic tape as cassette/music tapes and video/movie tapes.

Now, most computers can store data on CD ROMs.
 

You probably even own several “CDs”. CD ROM stands for Compact Disc Read Only Memory. It is spelled disc instead of disk because it’s an optical disc. Although there are blank CDs you can buy to “burn” or copy music or games with, a CD ROM cannot be written on/to, they can only be read. CDR’s and CD-RW’s may be written on.

There are two primary kinds of memory that the computer uses. Read Only Memory or ROM is the permanent memory of the computer. When you buy a computer, it comes with the ability to do such things as make system checks when it is first turned on. This is the permanent memory working.

The other kind of memory is Random Access Memory or RAM. This is the temporary memory of the computer. RAM can change whereas ROM cannot. The main difference in RAM and ROM is that the data stored in ROM stays there and when you turn the computer off, it is still there when you turn it back on later. Anything you put in RAM will be lost when you turn the computer off. That’s why it’s always important to Save your work, but we’ll talk more about that later.

Software is another word you’ve probably heard in reference to computers. Software is simply program material for computers. It is instructions given to the computer telling it what to do. Contained on disks or CDs, such as games, TAKS tutorials, and word processing programs.

Instead of ounces or inches, a computer measures memory in bytes. A byte equals one character (a number, symbol, or letter). A kilobyte equals a thousand bytes, a megabyte equals a million bytes, a gigabyte equals a billion bytes, and a terabyte is a trillion bytes. That’s a lot of bytes!

When you turn on your computer, you’ll see a spot of light or a symbol that shows the exact place where you’re entering data. This is called a cursor. It shows where information is being input and where your words will come out when you start typing.

We hope this introduction to how computers work will help you in the future.

Five Very Important Rules to Remember When Typing in Tech. App. Class

1) Put space one between words. Put one space after a comma, period, exclamation point, or question mark. (, . ? !)

2) Never use capslock. Use shift for capital letters and the symbols at the top of the keys. Don’t type in all caps.

3) Except on your heading, don’t press return after each line, only after each paragraph. The computer will go down to the next line for you automatically. This is called wordwrap. Don’t go to the next line using the space bar or the arrows.

4) Start all sentences with capital letters and end all sentences with a punctuation mark. (. ? !)

5) Always save your work with your name and the name of the assignment. Assignments saved with only your name, only the name of the assignment, or untitled will not be graded.

Return to Student Resource Page