Introduction
Today we shall discuss the following topics:
· Basic concepts
· Historical overview of the development of computers
· Generations of computers
· Classification of computers
Computer is fast becoming the universal machine of the 21st century. Early computers
were large in size and too expensive to be owned by individuals. Thus they were
confined to the laboratories and few research institutes. They could only be programmed
by computer engineers. The basic applications were confined to undertaking complex calculations in science and engineering.
Today, computer is no longer confined the laboratory. Computers and indeed, computing have become embedded in almost every item we use. Computing is fast becoming ubiquitous. Its application transcends science, engineering, communication, space science, aviation, financial institutions, social sciences, humanities, the military, transportation, manufacturing, extractive industries to mention but a few. This unit presents the background information about computers.
Objectives
The objective of this topic is to enable you understand the following basic concepts:
- Definition of the computer
- Basic understanding of data processing
- The concept of data and information
- Methods of data processing
- Characteristics of a computer
Definitions
Computer: A computer is basically defined as a tool or machine used for processing
data to give required information.
It is capable of:
- taking input data through the keyboard (input unit)
- storing the input data in a diskette, hard disk or other medium
- processing it at the central processing unit (CPU) and
- giving out the result (output) on the screen or the Visual Display Unit (VDU).
Fig. 1.0: Schematic diagram to define a computer
Data: The term data is referred to facts about a person, object or place e.g. name, age,
complexion, school, class, height etc.
Information: Is referred to as processed data or a meaningful statement e.g. Net pay of
workers, examination results of students, list of successful candidates in an examination
or interview etc.
Methods of Data Processing
The following are the three major methods that have been widely used for data
processing over the years:
a. Manual method
b. Mechanical method and
c. Computer method.
Manual Method
The manual method of data processing involves the use of chalk, wall, pen pencil and the
like. These devices, machine or tools facilitate human efforts in recording, classifying,
manipulating, sorting and presenting data or information. The manual data processing
operations entail considerable manual efforts. Thus, manual method is cumbersome,
tiresome, boring, frustrating and time consuming. Furthermore, the processing of data
by the manual method is likely to be affected by human errors. When there are errors,
then the reliability, accuracy, neatness, tidiness, and validity of the data would be in
doubt. The manual method does not allow for the processing of large volume of data on
a regular and timely basis.
Mechanical Method
The mechanical method of data processing involves the use of machines such as
typewriter, roneo machines, adding machines and the like. These machines facilitate human efforts in recording, classifying, manipulating, sorting and presenting data or information.
The mechanical operations are basically routine in nature. There is virtually no creative thinking. The mechanical operations are noisy, hazardous, error prone and untidy. The mechanical method does not allow for the processing of large volume of data continuously and timely.
Computer Method
The computer method of carrying out data processing has the following major
features:
a. Data can be steadily and continuously processed
b. The operations are practically not noisy
c. There is a store where data and instructions can be stored temporarily and
permanently.
d. Errors can be easily and neatly corrected.
e. Output reports are usually very neat, decent and can be produced in various forms
such as adding graphs, diagrams, pictures etc.
f. Accuracy and reliability are highly enhanced.
Below are further attributes of a computer which makes it to be an indispensable
tool for human being:
Characteristics of a Computer
Speed: The computer can manipulate large data at incredible speed and
response time can be very fast.
Accuracy: Its accuracy is very high and its consistency can be relied upon.
Errors committed in computing are mostly due to human rather than
technological weakness. There are in-built error detecting schemes in the
computer.
Storage: It has both internal and external storage facilities for holding data
and instructions. This capacity varies from one machine to the other.
Memories are built up in K(Kilo) modules where K = 1024 memory
locations.
