Computers are used for different things. A few of the things people use computers for are to solve math problems, write and check the spelling of their words, play games, do homework, help fly airplanes, and keep track of information. Computers have changed a lot over the past 150 years. An early computer that helped people keep track of numbers and solve math problems is the abacus. Chinese people have used them for thousands of years. Charles Babbage made a device in 1823 that was a calculating machine. It was used to solve math problems. He developed the idea of a machine having a central processing unit, memory for storing numbers, and programs on punch cards that would run the computer. As electricity developed, so did computers. The other major invention that helped to develop computers was the microprocessor. Ted Hoff made the first microprocessor in 1970. This was important because a lot of information could be programmed on a small chip. Computers that used to take up a whole room could then be made much smaller. When computers were really big, not many people could afford to have one. The microprocessor helped to make the size needed for a computer much smaller and more affordable. Before there were computers, there were other ways to send information over wires. Morse code was made up by a man named Samuel F. B. Morse in 1838. Morse code uses dots and dashes. A dot is when you hold down the telegraph for a short time. A dash is when you hold down the telegraph longer. The most widely used signal is sos. Here is the way you can signal sos in Morse code. To do a "s" you do three dot's. The "o" uses three dashes. People used to have to make the signals by themselves using their hands. Modern computers have transistors that use switches that turn on and off to send signals. ...
