The first section begins with the invention of the abacus in 3,000 BC. The abacus was the first human-made numerical calculator. By memorizing certain rules, the user could perform any mathematical equation. It is in fact the first computer, because it computed things. Aside from a brain, it was the first device that could compute numbers. 
 

ENIAC (Electrical Numerical Integrator And Calculator), the world's first electronic computer was invented in 1943. It was capable of performing math operations 1000 times faster than any machine. The drawback of this computer was it used  too much energy and was big to be as useful as the smaller machines that were later invented.
 

Until 1957, magnetic cores were used as storage devices. In 1957, magnetic tape was used as a much more convenient, and reliable form of saving information. More hard drive space allowed for bigger and more advanced programs. 

In 1959 computers became smaller due to a device called a transistor. The transistors replaced the vacuum tubes, and were a lot better because of the fact that they were small, used little energy, and were much faster than their predecessors.  
 

The integrated circuit was invented in 1965. Circuits were built into a like substance called silicon (which is a good (super)conductor of electricity). This was a big break for the computer industry because now big boards lined with transistors which took up a lot of space were replaced with small boards that  reduced the size of computers and made them more reliable, and less expensive. 
 

In 1971 Intel introduces its 4004 chip - the first microprocessor. Microprocessors allow computers think more quickly, and think more powerful thoughts. It made computers much faster, and allowed them to do more powerful things. The microprocessor is still used in computers today.
 

In 1980 Microsoft developed  BASIC for its personal computer. In 1981 IBM introduced its first desktop computer,  the Datamaster.