Computer Fundamentals

Chapter 1

• A computer is a very powerful and fast computing (calculating) machine.

• A computer can be defined as a device that can perform both arithmetic and non-arithmetic operations accurately on any data or information at a very high speed.

• The set of instructions given to the computer is called a program.

• A program can be defined as a set of instructions, which directs the computer to produce the desired results.

• GIGO- Garbage In Garbage Out. Means if incorrect data is input to the computer system or an incorrect program acts on the data, the output will also be incorrect.

Speed Calculation

Unit of Time Parts of a second

Millisecond (ms) One-thousandth (1/1000)

Microsecond (ms)

One-millionth(1/1,000,000)

Nanosecond (ns)

One-billionth(1/1,000,000,000)

Picoscon (ps) One-trillionth (1/1,000,000,000,000)

Characteristics of a Computer

• Speed: The speed of a computer in terms of nanoseconds and picoseconds.

• Accuracy: All computers have almost 100% accuracy.

• Reliability: Reliability of any computer system is typically in the range of 99.9%.

• Memory: It can store many data and easily to access them.

• Storage: It can hold huge numbers of data.

Basic Applications of Computers• Schools• Multimedia and hospital administration• Ticketing• Banks and Insurance• Scientific and engineering applications• Business and administrative applications• Avionics and space flights• Humanities• Police Work• Meteorology• Entertainment

Components of a Computer System

The Central Processing Unit (CPU)

The System Unit