Computer Fun Essay

By: Mr. Paterek

Computers have become an integrated part of our lives over the last half century. Nearly everyone uses a computer in some way. Many people use them to complete the tasks for their job each day. Many people use them to do the necessary work to complete their education. Many people use them for personal entertainment. No matter how people use computers, they have become accustomed to them and use them naturally and easily. There was a time that computers were totally foreign to society. In fact, they could not even be conceived of in people's wildest dreams. For that, we need to go WAY back. The time was before the kings ruled Europe. It was even before the Caesars of ancient Rome. Thousands of years before Julius Caesar ruled Rome, Stonehenge was built by Druids on the Salisbury Plain of what is now known as southern England. They built a circular temple out of giant blocks of stone. This temple was so large that parts of it were as far a several hundred meters from its center. The main part was circular in shape and about 40 or 50 meters across. Much further out were large stones set into the ground in a large circular configuration. They were set deep enough into the ground that they appear to be like stepping stones. It must have taken several life spans for the ancient Druids to build this structure. For one thing, the stones used to build it would have taken teams of dozens of people working with many teams of oxen or other beasts of burden to move the stones into place. Then they had to figure out exactly where the stones had to go. What was so important about the position of the stones? This structure was a calendar that was powered by the sun. The rising or setting sun would cast shadows onto certain parts of Stonehenge at different parts of the year. It had to take a lifetime of careful observation to determine exactly where the shadows needed to fall and at what time of the year they needed to fall there. Stonehenge is a giant computer made of stone that accurately predicts the summer and winter solstices and the spring and autumnal equinoxes. So, is it a temple or a computer?

There are structures that were built by the American Indians of the Southwest that were able to predict the phases and progression of the moon over a 20 year period of time. Many of these structures only exist as fragments of what once was, but there is still enough left to understand what they were capable of doing. Temples or computers?

Let's skip several thousand years and go to the mid 1800's. It was a time of manufacturing and industry. It was a time of steam power and locomotives. People were just starting to move to the big cities because that's where the new jobs were being created. People were in a state of change; our world was changing from an agriculturally based society to an industrially based society. It was during this time that Charles Babbage, an English mathematician, invented a machine he called the Difference Engine. It was designed to do complicated math calculations and store and print the results. By 1832, he had spent all of the grant money provided by the English government as well as some of his own. Only a small part of the machine could be produced, but that part was able to do computations of up to six digits. Even though his machine never did operate fully, the first modern computer is credited to Charles Babbage. Perhaps the technology wouldn't allow his machine to be produced, but it is important to keep in mind that the need was there. Rather than finishing his Difference Engine, he started work on his Analytical Engine. It was never finished. Was Babbage's machine actually a computer? This question makes it necessary to ask another question: What is a computer? In scientific terms, a computer is a processor of information. In answering this question, it becomes clear that his machine WAS an early computer because, indeed, it did process information - mathematical information. (go to top)

In the late 1880's, the US census was becoming very difficult to complete because of such fast population growth. A man named Herman Hollerith developed a system of punch cards that could keep track of information for the US census. His method was nearly ten times faster than the systems submitted by others. Hollerith's invention was a victory; the 1890 census of 62 million people was completed in just a few weeks. He nearly went bankrupt when he offered his tabulating machines to the railroads. After massive redesigning and personal investment, he was able to convince the railroad companies to use his new system. He later went on the start the International Business Machines company which we know today as IBM.

The next great advance for the computer took place during World War II. The Germans were using a top secret code machine called Enigma. A Polish engineer offered to design a machine that would solve the codes of Enigma. As a result, the British built a code breaking machine called Colossus. At the same time Colossus was being built, the US was developing a machine to calculate artillery trajectory. These calculations were extremely complex and could be done fast enough to keep up with the demand. A Moore School Physicist, John Mockley, said he could invent a device that could do the calculations at record speed. He, his partner Presber Eckert, and their team worked on the Electronic Numerical Integrator, and Computer or ENIAC. Their final machine was over 100 feet long and weighed over 30 tons! It wasn't finished in time to help during World War II, but it was a technological success. It had drawbacks though. It had primitive memory that had to be reprogrammed each time the machine was used. It also generated huge amounts of heat that limited its use to short periods of time.

Towards the end of World War II, John Von Neumann came up with pioneering new ideas for the modern computer. It was to have a processing unit, controlling unit, memory, input, and output. Its programming would be stored in an internal memory which would allow it to be reprogrammed. Programming would not have to be hard wired the way it was with ENIAC. This would make Von Neumann's much more adaptable.

At this time, Eckert and Mockley split off on their own and started the Univac company. They joined up with Remington Rand - a typewriter company. Univac produced computers that were geared for businesses. In 1952, they arranged to predict the winner of the presidential race between Stevenson and Eisenhauer in conjunction with CBS TV. They correctly announced before the end of the election that Eisenhauer would win.

In 1953, IBM produced the model 701. They did this to replace the bulky punch card system that had been used till this time.

Miniaturization

The space race was the next landmark for the development of the computer. In 1961, the Russians rocked the world by launching the first man into space and returned him back to Earth safely. It became obvious that it would be necessary that a computer as powerful as the huge IBM and Univac computers would also have to go aloft. In 1947 the first step toward the necessary miniaturization was taken. Three scientists at Bell Laboratories produced the transistor. The transistor would replace vacuum tubes that were bulky and heavy. Where a 3" high vacuum tube was used before a tiny transistor could take its place. In 1959, engineers produced the first integrated circuit. The integrated circuit made it possible to mount all kinds of tiny electronic components onto a chip of silicon. Most computer chips or integrated circuits are made of silicon. A 30 pound computer made of transistor could be replaced by a 10 ounce integrated circuit. In 1969, the first microprocessor was developed by Intel. The microprocessor was an entire computer built into an integrated circuit. The microprocessor is what makes today's computers possible. This is what made the new computers so compact. The next step would be to mount these integrated circuits or computer chips together onto printed circuit boards. (go to top)

The personal computer

Half way through the 1970's, Steve Jobs and Steve Wazniak invented the Apple I in Palo Alto, California. They planned to sell it for $500, but it was too large and they subsequently came up with the Apple II. In 1976, the retired Intel millionaire, Mike Markala, joined with them and helped them market the Apple II. The following sections will discuss computer components or hardware. The hardware is all of the computer equipment. (CPU, disk drive, monitor, printer, etc.) (go to top)

Input devices

The early Apple computers did not have input devices like mice. Input is the data going into the computer or the process of putting the data in. Today, this input can be entered by keyboard, graphics pad, laser scanner, or voice. Back then all data was entered into the computer by way of the keyboard in command line mode. A keyboard is a form of input including letters and numbers like a typewriter. The keyboard was a carry over from the typewriter industry which was quickly adopted by the young computer industry. The keyboard seemed to be the only way to enter data. Data is information given to a computer instructing it to do certain things and then to show the results. It did not seem that there would be another way to enter computer data until Doug Englebart, a computer scientist, demonstrated a device he called a mouse. Today we have many input devices to input data into our computers such as mice, trackballs, touch pads, joysticks, microphones, infra red transmitters, and others. (go to top)

Output devices

Since a computer is a processor of information, something must happen to the information we put into the computer. It is sent back out of the computer in the form of output. Output is the results coming out of a computer that will appear on a TV or computer screen, be sent to a printer or plotter, be converted to sound waves by a sound synthesizer, or be converted to electrical signals by a modem or network card. Output can be sent out to a network in the form of electrical or optical signals which, in turn, can be received and decoded by other computers on the network. Networks can be small such as a handful of computers in a small office setting or huge as in the Internet. Documents, e-mail messages, sound files, pictures, and computer software can be sent as output over a network.

The output device that allows you to view the computer program that is in the computer is called the display. The display or monitor comes in a wide range of sizes and types. The desktop monitor that most of us have is similar to a TV set. It receives an electrical signal and projects it electronically on the screen by a device called a cathode ray tube. Laptop computers produce an image on a liquid crystal display. Other forms of displays work like movie projectors and allow the image to be projected onto a overhead screen so that large audiences can view a presentation. (go to top)

Printers have gone through just as dramatic a development as the computer itself. A printer is a form of output which prints the computer's results on paper. Earlier printers, called dot matrix printers were noisy and slow. They printed a document one line at a time. A printer head would glide across the page and tiny heads would strike through a ribbon of inky fabric. The tiny heads would be told, by the computer, exactly when and where to strike. These heads would strike the page hundreds of time for each line. The result was lots of noise and letters that were obviously made up of tiny dots. The dot matrix printers were not suitable for printing documents that needed a professional look. For that, the daisy wheel printers were used. These printers had a little wheel that would spin to the point where a letter was located. Then that part of the daisy wheel was struck against the inky fabric ribbon. An imprint of a letter was left on the paper. The daisy wheel printers looked much better and also allowed the user to select from several type styles or fonts. However, they were also rather slow and a page would take as much a 2 minutes to print. The laser printers were the printers that finally gave documents a professional look along with a faster speed. The laser printers worked more like a copy machine where the image was transferred to the paper by burning toner (an ink like powder) onto the paper's surface. Another advantage of the laser printers was a finer resolution. In other words, the dots were still there as with the dot matrix printers, but they were so fine, it took a magnifying glass to see them. The resolution went up to 600 dots per inch with laser printers. As software improved, people could work more and more with color pictures. Since people could begin to work with colored pictures on the screen, they wanted to start printing them in color. Unfortunately, laser printers could not print in color. The ink jet printers were developed to print color pictures. Like all of the other printers, the ink jet printers also interpreted pictures in terms of a grid of dots and produced the final picture a line at a time. The ink jet printers also have a very fine resolution and produce very detailed pictures that require a magnifying glass to see the tiny dots in the picture. (go to top)

Another output device that produces hard copy is the plotter. Plotters produce pictures in a very different way than printers. The printer uses a concept called raster to get from one point to another. When the printer draws a straight line, it finds the two end points draws a tiny set of stair steps between the two points. With the earlier printers, these stair step lines were quite pronounced. With the newer printers, the stair steps are so fine, it difficult to see anything but a straight line. The plotter, on the other hand, uses a concept called vector to draw a straight line. The plotter locates the end points of the line and simply draws a straight line between them. How is this done? The plotter actually holds a pen and guides it to make a drawing. The older plotters held the pen in one place rigidly while the piece of paper moved under it. This moving table did a lot of moving especially when the drawing being made was an architect's set of house plans. These E sized sheets of paper had to be moved nearly 3 feet to make a border around the edge of the drawing. These earlier plotters took up a lot of floor space and weighed hundreds of pounds! Newer plotters still have the capabilities of the old ones. They all still use all Hewlett-Packard codes between the computer and plotter. However, the newer plotters are called saddle plotters. This is because they are about the size of a carpenter's saw horse and the piece of paper is draped over the plotter much like a cowboy might throw a saddle blanket over his horse. Instead of the pen being held rigidly in place, it moves along one axis while the paper is moved by little rubber rollers along the other axis. All of the drawing is actually done along a narrow drawing surface that is almost 36 inches long and only a couple of inches wide. The saddle plotter is fascinating to watch. The paper slides back and forth with sudden, almost violent movement and the pen moves along a straight line going back and forth and up and down at an incredible speed. The final plotter drawing is extremely precise with variations of only a few thousandths of an inch!

Stereo speakers or headphones are output devices on many computers. Many computers are outfitted with audio software and hardware such as CD players to play music, DVD players to play feature length movies, and FM tuners that can bring in radio stations. After the media is read by the computer's hardware and software, it is converted to electrical signals and sent to the speakers.

How does a computer work? or Binary numbers

Understanding how computers work at the simplest level can be quite fascinating. At the most simple level, computers are only a series of electrical impulses that are turned on and off in different combinations and at very high speeds. Think of it this way. If you have a source of electrical power that you can turn on and off, imagine that when the power is on for a brief period of time, the computer is telling you to write down the number one. When the power is turned off for a brief period of time, the computer is telling you to write a zero. The computer can tell you a lot of things by just using zeros and ones. For one thing, the computer can count with these zeros and ones. How can that be? Don't you need more numbers like threes and sixes and eights? No, the computer starts with the number one by giving a short period of power turned on. As with our number system, when we count to nine, we run out of numbers, so we start over with a zero added to the back of the numbers, then a one added to the back of the numbers, and a two, and so on till we get to 99. Then we add two zeros. Our number system continues to grow in values of ten because ours is a base ten system. When the computer gives a short blast of power on to signify a one, it runs out of numbers like we do when we count. It needs to start over already! So, it adds a zero onto the back of the one to get the next number. That's "power on" "power off." The next number is one followed by one. That's "power on" " power on." OH OH! we just ran out of numbers again! We need to move to the next level just like we do when we go from 99 to 100. So, the computer's next number IS 100. That's "power on" "power off" "power off." The numbers that follow are 101, 111, 1000, 1001, 1010, 1011. And -- that's how many fingers and thumbs the computer says you have on your hands! The computer says you have 1011 fingers and thumbs when we say we have 10 -- SAME THING! This number system only has two digits. In other words, every number in the system is made up of only the two numbers - one and zero. It is called a base two counting system. The term binary is used by the computer industry to indicate a base two counting system. Most computers use the binary code to translate information into a language that the machine will understand. Each time the computer registers a one or a zero, this is called a bit of information. The number 11101011000111 would contain 14 bits of information. The number 101 would contain three bits of information. A byte is computer information that is stored in the binary digits 1 and 0 - called bits. A group of 8 bits is called a byte. Normally it takes 8 bits to create a letter of the alphabet or an Arabic numeral - those are the numbers that we are familiar with. a typical page of written text, having no pictures or other imbedded information, would be equivalent to 2000 to 3000 bytes. A thousand bytes would be called a kilobyte - just like the prefix from the metric system. A million bytes would be called a megabyte. A billion bytes would be called a gigabyte. The memory of a computer is measured in bytes. We often hear of memory chips for computers in terms of 64 megabytes or 16 megabytes. Computer storage is also measured in bytes. Older hard drives didn't have much storage capacity. They only held about 10 megabytes of information. They were easily filled up with documents or computer programs. Hard drives have continually gotten bigger over the years. Today's hard drives will sometimes hold 20 or more gigabytes of information. Who knows how much information they will hold in 10 years! (go to top)

Hexadecimal code

It is pretty obvious that because cavemen and cave woman were born with ten fingers and thumbs, that they would naturally learn to count in base ten. In other words, when they were hunting for saber toothed tigers, they used their fingers to tell their hunting party how many saber toothed tigers were hiding behind a tree. When they counted thirteen of them, it was easier to count out ten of them and somehow commit that to memory. Perhaps they could throw a rock on the ground because they already used up all of their fingers once. Then they could somehow communicate that there were three more too. They could throw 2 rocks on the ground if they counted their fingers twice. Then they could add any more to that. At any rate, they counted in sets of ten because they had that number of fingers to work with. Now, try to imagine if cavemen had been born with 16 fingers and thumbs. They would count 16 sabertooth tigers before having to start over again. It would come naturally to do everything in sets of 16. Of course, many generations later, when numbers came along, they could not stop at 9 digits and start over with the tenth. They needed more characters before starting over. There would be zero plus 15 unique characters in order to be able to count in base 16. So, how about if the 16 fingered cave man counted like this: 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D. E, F. Then start over with the teens looking like this: 11, 12, 13, 14, 15, 16, 17, 18, 19, 1, 1B, 1C, 1D, 1E, 1F. The base sixteen numbers would continue in the same progression until you got to 100, but 100 does not mean 100 in base ten. the base sixteen 100 is actually 16 X 16 or 256 in base ten! How would you like to learn those multiplication tables? But why are we talking about base 16? It is the other number system that computers use. It is called machine language. It is also called hexadecimal (hexa meaning 6 and decimal meaning 10 or 6 + 10). Why would computers need to use base 16. Why can't they use base 10 so we can understand what's going on more easily. It is because the computer can convert back and forth between base two or binary and base 16 or hexadecimal quickly and efficiently. There is a perfect 1 to 8 ratio when the computer goes from binary to hexadecimal and back again. It's a clean conversion with no surprises like repeating decimals or non-repeating/continuing decimals. If the computer converts between binary and base ten, it gets messy and errors start to occur. That is why computers use base 16 for machine language. So, whenever you see numbers mixed with the letters A through F, you will know that you are looking at hexadecimal code.

Storage

There are other forms of information storage. On form of information storage that has been around a long time is called a floppy disk. Floppy disks are plastic disks with magnetically sensitive surfaces. The computer can pick bits of data from anywhere on the disk. A floppy disk can store information outside the computer. A blank floppy disk that has just been purchased from the computer store is not always ready to have information stored on it. It must be formatted before it can be used. What does it mean to format a disk? Try to imagine a 500 page book with no page numbers, no table of contents, no chapter numbers, and there is no punctuation anywhere in the book. In fact, even the letters are all jumbled up in random order. That is what an unformatted disk is like. It is not ready to receive or give out information in any way, In fact, it is totally non-functional. The be usable, the disk must be told how to organize information, so that it knows how to retrieve it when asked to do so. After formatting, which take the computer about two minutes to do, the disk can store information -- it has the equivalent of page numbers, chapter numbers, punctuation, and all of the letters have been unscrambled and put into the correct. Well, it isn't exactly that way, but that's probably the best way to explain it to someone unfamiliar with formatting. The old 5 1/4" diameter floppies did not store very much information, They would probably be able to store the equivalent of a phone book for a city of about 100,000 people. They were also pretty fragile and lost information when they were bent or warped. They were replaced by the 3 1/2" diameter floppy which could store a little bit more information. The 3 1/2" floppy was inside a little stiffer case and had a sliding cover protecting the delicate surface of the disk. These disks were more reliable and did not lose information or "crash" as often. The trouble with floppies, they were filled up with information too fast. Something with more capacity was needed for information storage outside the computer. A number of different formats have been tried over the last few years and it seems that two of them are the most reliable. The Zip disk is able to store 100 to 250 megabytes which is 100 or more times what the floppies could store. The case that the zip disk is in is much stiffer that of the floppies, so Zip disks seldom become bent or warped. The Zip disks are also magnetically sensitive which means they can lose information if exposed to magnetic fields -- that risk is not a high one, but when it happens, the disk is usually unusable until it is reformatted. Another popular form of information storage is the compact disk - read only memory or CD ROM. These disks are able to hold 350 megabytes. They are made of stiff plastic and are quite rugged. Since information is stored on them optically with the use of a laser, they are unaffected by magnetic fields. It takes a lot to render a CD ROM useless. The earlier CD ROM's had one major drawback - they could not be reformatted and filled with new information. Once they were "burned," they could not be changed. They were a permanent form of information storage. Newer CD's are called CD RW's, which means they can be purchased blank and the consumer can put information on them. They are much cheaper than other forms of storage, hold a lot of information, and are difficult to destroy. For these reasons, they will probably be around for a while. One of the most convenient forms of storage is called a thumb drive or jump drive. These are small, easily removable memory drives that plug into the USB port on most computers. They are basically NAND-type flash memory designed with a USB 1.1 or 2.0 interface. They are hot-swappable, which means they can be plugged in and removed while the computer is still turned on. Thumb Drives are solid-state with no moving parts. At this time, they come in sizes as big as 4.0 gigabytes; who knows how much more storage will be built into them in the future. (go to top)