Central Processing Unit

Portion of the computer that fetches and executes instructions.
Consists of an ALU, a control unit, and registers.
Referred to as a processor in a system with a single processing unit.

Core

An individual processing unit on a processor chip.
May be equivalent in functionality to a CPU on a single-CPU system.
Specialized processing units are also referred to as cores.

Computer Generations

Generation	Approximate Dates	Technology	Typical Speed	Images
1	1946-1957	Vacume tube	40,000
2	1957-1964	Transistor	200,000
3	1965-1971	Small and Medium Scale Integration	1,000,000
4	1972-1977	Large Scale Integration	10,000,000
5	1978-1991	Very Large Scale Integration	100,000,000
6	1991-Present	Ultra Large Scale Integration	1,000,000,000

Computer Structure

1. Computer
• Input and Output
• Main Memory
• System Bus
• CPU


2. Central Processing Unit
• Registers
• Arithmetic and Logic Unit
• Internal Bus
• Control Unit


3. Control Unit
• Sequencing Logic
• Control Unit Registers and Decoders
• Control Memory