Introduction to Computers

The Journey Inside℠, an Intel® Education Program

Lesson 1: History of Computers

Throughout time, humans have invented ingenious calculating machines. One of the earliest was the abacus, which is about 5,000 years old. It wasn’t until the 1600s that mechanical calculators were invented that could add and multiply (but not subtract). In 1820, Charles Xavier Thomas de Colmar invented the arithmometer, a machine that could add, subtract, multiply, and divide. It was Charles Babbage though, in the mid-1800s, who designed mechanical calculating machines that would become the true ancestors of today’s computers. Ada Byron King (the Countess of Lovelace) worked closely with Babbage and is today considered to be the mother of computer programming.

Babbage did create a design for his ultimate calculator, the Analytical Engine, but it was never finished. However, it did anticipate the four components essential to modern computing: inputstorageprocessing, and output.

The only problem with Babbage’s (and other) mechanical calculators was that they were mechanical. The moving parts they relied on were slow and subject to failure. What makes modern computers possible are electronic components that enable calculations and other information processing to be done quickly and without moving parts.

Lesson 2: Four Components of Computer Processing

A computer processes information. A toaster processes bread. Although it’s a simpler device, a toaster is a good way to demonstrate the four components of computer processing: input, storage, processing, and output.

  1. Input: You put a slice of bread into a toaster.
  2. Storage: The toaster keeps the bread inside the toaster.
  3. Processing: The toaster toasts the bread.
  4. Output: The toast pops out, ready to eat.

Hardware vs. Software

Both a toaster and a computer have physical parts you can touch. A toaster, for example, may have a dial to select how long to toast and a lever you push to start the toasting cycle. A computer has a keyboard, trackpad, and monitor. These physical parts are called hardware.

But only the computer has something called software that enables it to figure out what to do with the input you give it. Software gives the computer the ability to process many kinds of information. In contrast, all a toaster can process are types of bread.

Another significant difference is that a computer has a microprocessor. The microprocessor is the device in the computer that performs most of the tasks we ask the computer to do—from playing online games to searching the internet. The microprocessor reads and performs different tasks according to what the software instructs it to do. It is what makes the computer such a versatile machine.

The key thing to remember is this: Both a computer and a toaster have four basic components to how they operate (input, storage, processing, and output). But unlike the toaster, the computer can do a lot more for us.

Lesson 3: How Computers Get Input

Computers are information processing machines. That means that you can use them to access and change information like numbers, text, pictures, videos, and music. Think about what you do to modify a sentence. Using the computer, it’s easy to add, delete, or rearrange words.

Input devices are used to provide information, or data, to your computer. If you type a sentence with the keyboard, it can appear on the computer screen. If you speak into a microphone, a computer can record your words. If you make funny faces at a video camera, a computer can record every one of them. Even the mouse or trackpad you are using is an input device!

Lesson 4: How Computers Store Information

When you are talking to someone on the phone, the person on the other end hears what you are saying, but then your words are gone. The words from your conversation aren’t stored on the phone. However, leaving a voicemail is different than having a live conversation. The voicemail system answers the phone and records and stores the information given by the caller.

To process information, computers need to be able to store it. Otherwise, like the phone, information would come and go before anything could be done with it.

Computers store all kinds of information. They store the information you give them and instructions from the software you’re using, plus the instructions they need to operate.

Computers use two basic kinds of storage to hold all of this information. Temporary storage is for new information that is actively being used for processing, known as random access memory (RAM). Long-term storage is for information that computers use again and again, such as the instructions the computer uses every time you turn it on. These instructions are stored in read only memory (ROM), a type of memory that does not accept new information.

Computers also use a variety of devices to store information that isn’t actively being used for processing. For more information, explore hard drives, optical discs, and removable media in the site glossary.

Computers Need to Remember, Too

When someone asks you to add two numbers together, you rely on your memory to remember the rules of addition. Computers also rely on memory to remember the rules for certain activities. Computer programs include the instructions, or rules, for different types of tasks. In this addition example, a computer would need a math program in its RAM to “remember” how to calculate the result from adding numbers together.

However, some things come automatically to humans. When you breathe or move your arm, you do so without having to remember how your muscles work. Computers have this kind of built-in memory too—ROM, which remembers only what it was programmed to remember at the time the ROM chip was manufactured (like how to turn on or off). Remember, information stored in ROM is “read only,” meaning it can never be told to do something different after it has left the factory. That would be like trying to reprogram your body to breathe water instead of air.

Different Kinds of Storage Media

Computers use RAM for the information they currently need to do a task. Parts of the program and data you are currently using are held in RAM while you are working with them. But what about the rest of the programs and information on your computer? They are stored in a variety of other media. You are probably familiar with many of the ones shown on this page. What you might not know is the amazing amount of information some of these computers can hold.

Lesson 5: How Computers Process Information

Computers use an integrated circuit to understand and act on certain information. Of the many chips in a computer, the microprocessor is the most complex.

A simpler kind of chip is used to make digital watches, remote controls, and video game consoles. The chips in these devices are called embedded processors. They’re made to perform the instructions that are originally coded onto them, and you can’t install new software to change what they do. For example, you can’t instruct a digital camera to do word processing or instruct a microwave to monitor your heart rate.

Microprocessors are much more versatile than embedded processors. If you change the software you’re using, you can go from doing word processing to playing an online game. If you change the software again, you can explore the internet. Instead of being designed to do one thing, microprocessors in computers are designed to do whatever the software you select instructs them to do.

Lesson 6: How Computers Deliver Information

All the processing power in the world wouldn’t matter much if you couldn’t get output from a computer. In fact, you’re looking at output right now on your screen. You told the computer you wanted to view this page, and the software and microprocessor inside it is responding by displaying the page on your monitor. Other kinds of output include sound from a computer’s speakers and documents printed by a printer.

Lesson 7: Which Is Smarter?

Computers are sometimes called electronic brains. But are they really brains? Let’s compare.

First, let’s look at how brains and computers work. A human brain uses special cells called neurons that continuously work together to process information and respond with an action. A computer uses a collection of circuits, called a microprocessor, that are built and programmed to respond to input in a certain way. Neurons are living cells, while circuits are electronic components.

Now let’s consider which is smarter. The answer depends on how you define “smart.” If being smart is determined by speed, a computer would win. A person would take a few seconds to add two three-digit numbers (245 + 987), but a computer can complete several million long-division problems (387 ÷ 243) in a single second. A computer is also tireless because electronic circuits don’t wear out. A human doing long division all day would want lots of breaks—and a good night’s sleep!

What if being smart depends on having a good memory? In that case, a computer would win too. A computer can store an entire library of books in its memory and recall them without a single mistake. Now consider a person. Have you ever tried to memorize a long poem? It’s an enormous task for a person to memorize lengthy texts.

What if being smart depends on being able to make well-reasoned decisions? Here a person wins by a huge margin. Computers can only calculate and sort information based on the software we design for them, and the choices computers make are limited to what is written in the software. But comparing this to a person, humans don’t need software. We can sort and calculate facts using our own knowledge and experience. We can also make judgments and decisions based on whatever facts we’re confronted with—not just the facts a computer has been programed to recognize. In this way, we’re a lot smarter than computers.

What if being smart depends on the ability to think original thoughts? Here again, humans have an enormous advantage because we think original thoughts every day. The evidence is in the inventions, art, and books we have created over time. The computer is one such invention. So are computers capable of individual thought? So far they’re not; however, artificial intelligence (AI) is a field of science devoted to developing devices that someday may be able to reason and solve problems on their own without relying on a certain program. It’s important to remember though that no matter how “intelligent” we make computers, they will only be as smart as the software we humans create for them.