CPU: Central Processing Unit
CPU stands for Central Processing Unit. It is also known as a brain of the computer. It carries out instructions and computer programs and performs all the basic arithmetical and logical operations. CPU is installed in the motherboard on a specific area known as CPU socket.
Traditionally the term CPU refers to a processor which includes control unit and arithmetical logical unit.
Central Processing Unit (CPU) = Arithmetical Logical Unit (ALU) + Control Unit (CU)
Components of CPUs
Arithmetical Logic Unit: This is a key part of the CPU. This is responsible of performing all the logical and arithmetical operations.
Control Unit: It is the most important part of the CPU. It instructs the complete computer system to carry out a particular task.
Registers: Registers are the special type of memory devices. They store the data that have to be processed and already processed by the processor.
Types of CPUs
CPUs can be divided in three major categories:
- Transistor CPUs
- Small Scale Integration CPUs
- Large Scale Integration CPUs
The term CPU was first used in Computer industry in the early 1960’s. Initially the term CPU was used to define a device for software execution and it came with the advent of the stored program computer. Some of the important events related to history of CPU are as follows:
- Silicon, the basic component of processors, was discovered by Baron Jons Jackob in 1823.
- In 1903, Nikola Tesla patented the electrical logic circuits (gates or switches).
- In 1947, the first transistor was invented by John Barden, Walter Brattain and William Shockley at the Bell Laboratories.
- In 1958, Robert Noyce and Jack Kilby developed the first integrated circuit.
- On 15 November 1971, Intel introduced the first microprocessor, the Intel 4004.
- In March 1991, AMD introduced the AM386 microprocessor family.
- On 22 March 1993, Intel released the Pentium processor, a 60 MHz processor with 3.1 million transistors.
- On 4 January 2000, Intel released the Celeron 553 MHz bus processor.
- On 22 April 2006, Intel released the Core 2 Duo processor E6320.
- In November 2008, Intel released the first Core i7 Desktop processors.
- In January 2010, Intel released the first Core i5 Mobile processors (i5-430M and i5-520E).