by the fourth generation of computers, the use of magnetic cores had virtually disappeared and chip circuitry was becoming increasingly smaller. the technique by which this was accomplished was called large scale integration (Lis) (see Figure 1-26). LST was based on the principle that the closer the components, the shorter the route electricity has to travel. With shorter routes, processing is faster. LSI put thousands of transistors on a single silicon chip and provided faster processing. Yet even at this time, the functions that could be,performed on a chip were permanently fixed during the production process.
Ted Hoff, a young engineer at Intel Corporation,introduced an idea that packed onto one chip the arithmetic and logic circuitry needed for computations. Other control functions such as input, output and memmory,were placed on separate chips. The result was a single, programmable processing unit. This was called the microprocessor or "computer on a chip". The microprocessor could be made to act like any kind of calculator or computer on a chip".