The Central Processing Unit of a computer, or CPU, is the part of the computer that actually does the processing of data. The design of each different model can vary, but some of the parts that are fairly homogenous, are the arithmetic-logic unit, the control unit, and several registers. A memory registration unit can often also be found.

Intel C4004

Intel 4004 microprocessor

In the early days of computing, when everything was much larger and bulkier, naturally most of the parts of the CPU were separate components. The first silicon microcomputer chip, developed by Texas Instruments, was made in 1958. Then along came Intel, and in 1971, they created the Intel 4004 microprocessor, which brought along a new era of the CPU. Similarly to the one by Texas Instrements, it was located on a small silicon chip, and naturally as time passed, its processing abilities and complexities increased substantially. Along these lines, a few years earlier Gordon Moore, a co-founder of Intel, came up with an idea that he called Moore's Law. This law, as said in this article, states that a computer chips capabilities would double every year, for the foreseeable future.

Any chip that holds a CPU is called a microprocessor. Transistors, a main physical component in these silicon chips, are very small semi-conductors that have multiple parts including electrons, and holes that attract protons. In this way these small grooves, in these tiny chips, are able to carry a message and control much larger messages being passed within the chip. You can learn more about transistors from this article. For perspective, in this first microprocessor there were abpout 2,300 transistors, and in 2016, the most powerful commercially available microprocessor had over 7.2 billion.


the inside of an Intel i7 processor

The arithmetic log unit, or ALU, as talked about in this article, is the part of the processor that performs the most basic operations, the types of math we typically learn in elementary and middle school. The only different between what the ALU does and how we would learn math, is of course its all in binary, so its really just understanding 1 and 0. All of this is based off of Boolean Algebra. The CPU also has in Its own internal clock, that makes sure everything is synchronized, and it is working accurately together.


basic diagram of a CPU

The control unit of the CPU, is the part that controls the processors synchronization with other parts of the computer and external operations. It also connects to memories, or the RAM of the computer, as well as the input output ports of the coputer. The CPU should be able to access al of these parts while responding to commands such as "wait" and "interrupt". For the CPU to function, you of course need it to be connected to power. Power to the computer is run from the Power Supply through the Motherboard, and finally to the CPU, so that it can perform all of its duties.