The 80486 microprocessor, a kind of CPU from the 1990s

The TMS1100, by Texas instruments came out in 1974, and has been used for many applications, such as doorbells or light switches.

A microprocessor is an electronic component that is used by a computer to do its work. It is a central processing unit on a single integrated circuit chip containing millions of very small components including transistors, resistors, and diodes that work together. Some microprocessors in the 20th century required several chips. Microprocessors help to do everything from controlling elevators to searching the Web. Everything a computer does is described by instructions of computer programs, and microprocessors carry out these instructions many millions of times a second.