Have you ever looked at your computer and felt sure that it was a machine conjured up from a Science Fiction movie, zapped with gamma rays and moonbeams, and sent to you by gremlins bent on tormenting you? Well, you are not alone!
Just what is that mysterious machine?
If you are over 40 - and especially, if you are over 50 - you have seen, felt, touched, and possibly owned all of the pieces and parts. Yes, it is true! The computer is just recycled technology, some of which has been around since before any of us were even born. If you recognize, or can identify the following list of items, then you know all about the computer. If you can't, ask your grandmother!
1. A power strip (that long bar with the electrical plugs in it)
2. Extensions cords
3. Record player
4. Transistor radio
5. Window fan
6. Electric motor (like in a blow dryer or kitchen mixer or can opener)
7. Digital clock
8. Telegraph system
9. Electricity
10. Plastic Box
Well, that is pretty much it. Way!
How did you do? Pretty good, huh? (Never underestimate the value of maturity!)
Now let's put it all together to build a computer. Please note that I am using layman's terminology and oversimplifying the situation.
We'll start with the plastic box (#10). If you have a desktop computer, you probably have what is called a tower or mini tower. If you have a laptop or notebook, you have a much smaller version. The plastic box is just that - a plain, ole, plastic box. Just like buying a box of donuts, we have to have something to hold the donuts. This plastic box, with all the computer goodies inside, is called a CPU - central processing unit.
Inside, on the bottom of the box is the power strip (#1), which is called the Motherboard, because it is the thing that "gives life" to all the other pieces and parts. Of course, the motherboard does not look like a power strip, but that is the function that it performs. Everything else in the plastic box connects to the motherboard.
The extension cords (#2), called cables and plugs - depending on the function - connect everything to the motherboard (the distributor of the electricity). Some of the extension cords are called ribbon cables. This is because they look like wide strips of ribbon like you would use to decorate a Christmas present. They are (usually) gray, plastic/rubbery/flexible strips with ribs. The ribs can be thought of as the lane dividers in an interstate highway and they do the same job - they keep traffic in its rightful lane and keep traffic from running over each other. The plugs do the same thing. Instead of being a ribbon shape, they are a group of individual, multi-colored wires with a common connector - like you would find if you took your telephone apart. These cables and plugs are just like the extension cords in that they are male and female (the plug in your wall is female; the end of the extension cord is male; the male plugs into the female to make the connection) and they match the opposite gender to make a connection. The connectors don't look like extension cord ends, but the principle is the same.
Just remember that every piece and part will make a connection to the motherboard by connecting directly, by extension cord, or by connecting into another piece or part that connects into one of the first two.
The record player (#3) is the hard drive (well, kind of). The hard drive is the storage unit for everything. It is a metal box that is about 4 - 6 inches wide and about 6 - 8 inches long. This is just to give you an idea. Sizes will vary with make, model, brand, and category. When you open the little metal box, there is a little metal disk that looks like a tiny little metal record from days of old and there is a tiny little arm that moves over and sets down into the groves of the tiny little record. The record spins just like the old turntable. The record player technology only accounts for the play back of stored info. Also incorporated here is tape recorder technology, which captures new additions and saves to the hard drive.
Next we have the transistor radio (#4). This is a little more difficult to explain. If you know how a transistor works, it will be easy to understand its relation to the computer. If not, I am going to try to give you the tip-of-the-iceberg, really, really broad overview.
Let's start with how a transistor looks. The visual is an important element. So, if you had a transistor radio, then you have the visual. If not, bear with me. We start with a small piece of metal, oh say, the size of a man's wallet. It is very thin. When you run your fingers across the top, it feels bumpy and irregular. It looks like someone took some liquid metal and dribbled it all over the metal base, but not in any kind of pattern, and let it dry.
The deal here is that there is a pattern. We just can't see it. The purpose of this little metal, bumpy thing (called a "card" in the computer world) is to move electricity and in the moving of the electricity, regulate where it goes and how it gets there. This is accomplished by those little bumps on the board. They are not really bumps. They are, in fact, gates. The gate opens and the electricity moves through. The gate remains closed and the electricity runs into it, but cannot pass, so it changes direction. The electricity is always looking for an open gate and therefore, a path to travel. On any one given card, there can be thousands of paths and each path executes a command. So, we have video cards, audio cards, modem cards, etc. These cards plug directly into the motherboard and perform the tasks they were created to do.
The window fan (#5) is the easy one. Generally found in the back of the plastic box, there is a small vent, which is the exhaust. Other vents can be found elsewhere in the plastic box. A tiny little fan keeps the air circulating. Your computer generates a lot of heat. Be sure to keep the flow of air circulating by keeping your vents clean and not obstructing the plastic box.
The electric motor (#6) is the power pack in the back of your computer. The external electric cord that plugs into the wall begins here. The electricity (AC [alternating current]) flows from the wall plug into the power pack. There, it is converted to DC (direct current) and fed into the computer. [Note: this was the case a few years ago when I was working with power sources. To the best of my knowledge, this has not changed].
There are other items inside the plastic box, too. There is a clock, a processor, a BIOS storage, and the temporary storage bin called RAM (Random Access Memory)
For the digital clock (#7) and the telegraph system (#8) we will be leaving the CPU and moving to the external pieces of the computer.
First is the digital clock (#7). You know this technology as the computer monitor. Yes, you read it right! The digital clock technology is simple. There are five columns on the face of a standard digital clock. Each column is filled with light bulbs (kind of). When it is 12: 30, the light bulbs light up and appear to be a 1, a 2, a :, a 3, and a 0. The bulbs that do not conform to these designs stay dark. This is how your computer monitor works. These little light bulbs are called 'pixels'. The smaller the pixels and the closer together they are, the more fluid the image on the screen. In the olden days (10 or 12 years ago - an eon ago in the computer world), the pixels were larger and spaced farther apart, so that you could see the dark between the lights. This created a choppy, broken look to the letters and numbers. You may have seen this on the digital clocks of yore.
Next is the telegraph system (#8). On the old telegraph system, the technology was simple. There was a wire from point A to point B. On each end was a transmitter/receiver (called a 'key'). The electricity passed through the transmitter/receiver in the intervals specified by the operator of the key. Morse invented a short cut language (a series of dots and dashes) to be used called Morse Code ('Help' became SOS, for example). The key operator would open and close the key in order to let "dots" or "dashes" of electricity slip onto the wire and travel to the end of the line, where the receiver part of the key there translated the electricity bits into a tapping sound.
This technology is the basis for the computer functioning. Electricity is bundled into packets (like the dots and dashes of Morse code) and sent over the wires, where it is collected and translated by the 'receiver', which is different for different "languages".
The telegraph system is the basis for your keyboard. If you are reading this, you speak English. Your computer doesn't have a clue about English. It has different languages. So, you look at your keyboard and you want to type 'apple', so you hit the 'a' key. This key, marked A, has a translation to a different language that the computer understands. The electrical impulse that is sent to the computer when you hit 'a' is collected by the translator. The translator says (in computer language), "Hey, computer monitor, light up enough light bulbs to make an 'a'." And, you see an 'a'. When you get 'apple', you decide to save. Then the keyboard says, "Hey, tape recorder, record this to the record player and keep it for later." (Well, kind of). All of the pieces and parts 'talk' in computer language using packets of electricity.
In order for the pieces and parts to talk and respond, they must be directed by software.
The pieces and parts are hardware, and hardware cannot not perform or produce without the software.
Think of hardware as a car and software as a driver. The car is fast. It can go forward, backward, turn left or right, and stop on a dime. And yet, without a driver to give the commands, the magnificent car would never leave the garage.