COMPUTER: - Computer is an electronic device which takes some input, perform operation and after processing give output.
CENTRAL PROCESSING UNIT (CPU): - The CPU is the control centre for a computer. It guides, directs and governs its performance. It is the brain of the computer. The CPU has two components which are responsible for different functions. These are Control Unit (CU) and Arithmetic Logic Unit (ALU).
ARITHMETIC LOGIC UNIT (ALU): -It performs all the arithmetic operations (+,-,*, /) and logical operation (<,>, =, <=,>=, <>).
CONTROL UNIT (CU): - The CU controls and guides the interpretation, flow and manipulation of all data and information.
INPUT UNIT: - The input unit is formed by the input devices attached to the computer. An input unit takes the input and converts it into binary form so that it can be understood by the computer. Example: - Keyboard, mouse, mike, joystick etc.
OUTPUT UNIT: -The output unit is formed by the output devices attached to the computer.
The term ‘computer generation’ is often used in relation to the hardware of computers. Each phase of computer development is know as a separate generation of computers. Each phase of development is characterized by type of switching circuits it utilizes
THE FIRST GENERATION COMPUTER (1949-55)
Some key features of first generation computers are :
DIGITAL COMPUTER: - A computer that performs calculations and logical operations with quantities represented as digits, usually in the binary number system. Every computer has a set of instructions that define the basic functions it can perform. Sequences of these instructions constitute machine-language programs that can be stored in the computer and used to tailor it to an essentially unlimited number of specialized applications.
ANALOG: - A computer or computational device in which the problem variables are represented as continuous, varying physical quantities. An analog computer implements a model of the system being studied. The physical form of the analog may be functionally similar to that of the system, but more often the analogy is based solely upon the mathematical equivalence of the interdependence of the computer variables and the variables in the physical system.
HYBRIDE: - Hybrid computer utilize the best qualities of both the digital and analog computers. In these computers some calculations take place in analog manner and rest of them take place in digital manner. Hybrid computers are best used in hospital where analog part is responsible for measurement of patient’s heart beat, blood pressure, manner and rest of them.