Before the development of microprocessors, the CPU electronic integrated circuit made of separate TTL; earlier, individual transistors; before that, from vacuum tubes. In fact there has been a simple design for the engine computer on the basis of mechanical parts such as gear, shaft, lever, Tinkertoy, etc..
The evolution of microprocessors has been known to follow Moore's Law which is the increase in performance from year to year. This theory was formulated that the calculation power will double every 18 months, a process that really happened since the early 1970s; a surprise to people who are related. From the beginning as a driver in the calculator, the development has been toward the domination of power in various types of computer microprocessors, each system from the largest mainframes to the smallest grasp computers now use microprocessors as its center.