Data Processing (DP)

A DP system involves the use of a computer and related equipment for analysing and recording many facts. Data are obtained from numerous sources and are processed quickly by being converted into a code consisting of electrical impulses.

Digital computers count numbers (e.g. trip mileage on a car).

Analogue computers are used mainly in scientific research and measure physical variables, e.g. voltage or speed (e.g. the speedometer of a car).

Business processing involves the digital computer.

Figure below shows the five components of a computer. These components are:

Input

This consists of data to be processed and the instructions to process the data. The sequence of instruction to the computer is called the program.

Fig. 1. Data processing system. Computer installation.

The following media may be used in preparing the input from the source of data: punched cards, punched tape, magnetic disks, optical scanners, magnetic ink character readers, a console typewriter.

Punched cards and tapes are cheaper and adaptable, but are bulky, susceptible to damage and unable to hold large amounts of data, they are also slow in use. They are rarely used now.

Storage

This unit is often called the memory and retains input in coded form. Data are stored internally by magnetic hard disk or externally in the form of floppy disks, punched cards, paper tape, magnetic drums or tape.

Arithmetic unit (or processing unit)

Data are mathematically manipulated according to the program.