Computer Fundamentals

Computer:
Computer can be defined on an electronic device that accept data, process then at a high speed according to a set of instructions provide to it and produces the desired output. So computer is a programmable machine.

Generation of computer: 
Generation means variation between different hardware technologies

1^st generation: (1946-1956):
First generation computers are made with the use of vacuum tubes. These computers used machine language for programming.

Disadvantages:

1. Occupied lot of space
2. Consumed lot of power
3. Produced lot of heat
4. Costly system

Example:     ENIAC(Electronic numeric integrator and computer).
                     UNIVAC(Universal Accounting company)

2^nd generation: (1957-1963):
The computer in which vacuum tubes were replaced by transistors are called second generation of computers these computers used assembly language for programming.

Advantages:

1. Less expensive
2. Consumed less power
3. Produced little heat
4. Less cost and work at higher speed

Example: IBM 7090, IBM 7094.

3^rd generation: (1964-1981):
The computers using the integrated circuits came to be known on the third generation of computers. These used high level language.

Example:  IBM 370, Cyber 175

4^th generation: (1982-1989):
The computers which were built with microprocessor are identified on the fourth generation computers these computers use VLSI chips for both cpu and memory.

Example: CRAY-2, IBM 3090

5^th generation: (1990- up to till):
Fifth generation computers are under development stage these computers use ULSI chips. ULSI chip contains thousands of components into a single IC. Aim of these computers is develop the artificial intelligence.

Hardware:
The physical parts of a computer- the plastic, glass, silicon and metal parts that compose a machine. These parts sometimes called Hardware.

• A cpu or central processing unit, which is the brain of the computer, where all the actual computation takes place.
• Main memory, which is short-term storage.
• An input device, usually a monitor or screen, on which the computer displays the results of its computations.
• Secondary memory-long term memory