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From Abacus to Macintosh | |
| Ancient Times | |
| Since the earliest times people used their fingers
to show "how many." They could show the number of animals killed
on a hunt. They could show the number of people living in a dwelling. It
was easy to show large numbers in groups of ten by holding up both hands.
That is how ten became the basis of our number system today. Primitive people also needed a way to calculate and store information for future use. To keep track of the number of animals killed, they collected small rocks and pebbles in a pile. Each stone stood for one animal. Later they scratched notches and symbols in stone or wood to record and store information. |
One of the first tools used to express numbers was the abacus. The Chinese abacus was developed about 5000 years ago. It was built out of wood and beads. It could be held and carried around easily. The abacus was so successful that its use spread from China to many other countries. The abacus is still in use in some countries today.
The abacus does not actually do the computing, as today's calculators do. It helps people keep track of numbers as they do the computing. People who are good at using an abacus can often do calculations as quickly as a person who is using a calculator ! |
| 1. What was the earliest method people used for counting? 2. How did this method lead to our use of the decimal number system? 3. What tool, invented by the ancient Chinese, is used to help calculate? 4. Why do you think this ancient device is still used today? | |
| The 1600's | |
| Throughout history, people have developed systems of numbers and ways of counting. They have looked for ways to make calculating easier. In 1617, John Napier, a mathematician from Scotland, invented calculating rods called Napier Bones. The rods were used to help people multiply large numbers. |  |
| Each rod contained the multiples of a number. By moving the rods around and reading rows of numbers, a person could do a few additions to get the product of two large numbers. The rods did not actually do the multiplication. They helped a person compute a product quickly and easily. | |
| Some years later, in 1642, a young French mathematician named Blaise Pascal was working in his father's office. His job was to add long columns of tax figures. Doing all this adding was boring and time- consuming. So, Pascal came up with a way to get the job done faster. He invented a machine, the size of a shoe box, that could add and subtract numbers. |  |
| Pascal's Arithmetic Machine used gears. They were notched wheels that moved each time a number was added or subtracted. The machine worked very much like an odometer on today's cars. The numbers O through 9 were printed on the edges of a row of wheels. When a wheel made a complete turn from O through 9, a small notch caused the next wheel to the left to move up one number. The Arithmetic Machine was one of the first machines built that could actually do computing. | |
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| During the next fifty years, other calculating machines were invented. They were not much of an improvement over Pascal's Arithmetic Machine. Then, in 1694, a German mathematician, Gottfried Wilhelm von Leibniz, built a very clever calculating machine. It was called the Stepped Reckoner. It could multiply and divide as well as add and subtract. Leibniz's Stepped Reckoner used "stepped cylinders" rather than gears and wheels to do its calculations. | |
| The machines invented by Pascal and Liebniz were complicated. They had many moving parts. In those days it was hard to build accurate copies of the machines. So, even though the original machines worked well, very few of them were made. |  |
| The l800's | |
| In 1801, Joseph Jacquard of France invented a new type of loom for weaving cloth. Punched cards were used to control the operation of the loom. A needle that passed through a hole in the card pulled a thread that became part of the pattern. The threads that could not pass through the card were not part of the pattern at that point. The process was repeated over and over. As a new card moved beneath the needles, its pattern of holes determined which needles would pass through, pulling different colors and kinds of threads. Any time a weaver wanted to repeat a pattern, he simply ran the same cards through the loom in the same order. | |
| Jacquard did not have computers in mind when he designed his punched-card loom. But, his idea of using punched cards to store information was to be used by a number of computer inventors in later years. |  |
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| Perhaps the first calculating machine that can be truly called a computer was invented in England by Charles Babbage in 1835. Babbage's dream was to build a machine that could do more than calculate big numbers. It would receive instructions. It would process and store information. It would print the results. He planned to call it the Analytical Engine. Babbage planned to use punched cards for the numerical information. He also planned to print out the results. | |
| Babbage was a respected scientist, but most people could not understand his new and unusual ideas. He was called "eccentric." He had a hard time finding anyone who would lend him money to build the Analytical Engine. However, a gifted mathematician, Lady Ada Augusta Lovelace, saw that the Analytical Engine could be an important machine. She supported Babbage in trying to raise money to build it. One of her most important contributions was to convince Babbage to use the binary number system in his machine, instead of the decimal number system. Using binary numbers would make the Analytical Engine work more efficiently. |  |
| Ada Augusta Lovelace also wrote about
Babbage's plans for the Analytical Engine. From these writings, it is clear
that his plans were for those of a modern computer. The Analytical Engine
had all four parts of a computer system: input, output, memory, and central
processing unit. Unfortunately, Ada Augusta Lovelace was the only person who appreciated Babbage's plans. Lack of money held up progress. Lack of precision tools made it very hard for Babbage to work on the Analytical Engine. In the early 1800's, electricity was not used. There were only mechanical tools to work with such as gears, cogs, and wheels. The tools of Babbage's time were just not precise enough to build this complicated machine. The Analytical Engine never worked. Babbage died thinking himself a failure. He never knew his ideas would be used more than 100 years later in the first "modern" computer. | |
