CPU (Central Processing Unit)

A CPU is a microprocessor - a large scale integrated circuit in small, rectangular packages, with multiple connecting pins.

An integrated circuit is a full electronic circuit fabricated on a single silcon 'chip'. All of the electrical components are etched onto a silicon substrate. You cannot amend or repair the circuit - it is a single component.

Connections between 'chips' and other components are made by placing the chip on a PCB. The connections are etched onto the board rather than being wires. PCBs are very reliable. The PCB that houses the CPU is called the motherboard.

The first microprocessor was the Intel 4004, introduced in 1971. It powered one of the first portable electronic calculators.

Nowadays microprocessors are very complex and fast. Whole sections of sites are devoted to discussing the merits of new processors. Their development is a cutting edge industry. By the time you purchase the latest computer your CPU will be out of date... a new one will be on the horizon before the latest computers hit the shelves.

Performance Assessment - how CPU performance is measured - so you can appreciate the advantages of upgrading and/or make a considered choice when buying a new system.

The CPU is the active part of the computer, which does all the work (data manipulation and decision-making). Processors consist of two main components: a controller and a datapath.

Datapath: The datapath handles all required arithmetic computations. It is the portion of the processor which contains hardware necessary to perform operations required by the processor (it 'does' it is the brawn of the computer)

Control: The controller is responsible for telling the datapath what to do, based on the instructions in the executing program. It is portion of the processor which translates the program instructions into instructions for the datapath (the brain)