DEFINITION, CHARACTERISTICS, CLASSIFICATIONS OF COMPUTER.
DEFINITION, CHARACTERISTICS, CLASSIFICATIONS OF COMPUTER.
BASIC COMPUTING CONCEPTS
A computer can be described as an electronic device that accepts data as input, process the data
based on a set of predefined instructions called program to produce the result of these operations as output called information. From this description, a computer can be referred to as an Input Process-Output (IPO) system, pictorially represented in the figure below:
Input - Process -Output representation of a Computer System
Data is a piece of basic raw fact, such as a score in examination or the name of a student, for example 55 or Malik respectively. There are three types of data - Numeric, alphabetic, and alphanumeric. Numeric data consists of digits 0 - 9 (e. g. 31).
while alphabetic data consist of any of the English language alphabets (e. g. Toyin). An alphanumeric data can consist of a number, an alphabet or a special character, such as a vehicle plate number (e. g. AE 731 LRN).
Information: data as described above contain no meaning, however, when it is transformed into a more meaningful and useful form, it is called information. The transformation process involves a series of operations to be performed by the computer on the raw data that are fed into it. The operation can be arithmetic (such as addition, subtraction, multiplication, and division), logical comparison or character manipulation (as in text processing).
Logical comparison means testing whether one data item is greater than, equal to, or less than another item, and based on the outcome of the comparison, a specified action can be taken.
Theoutput of the processing can be in form of reports which can be displayed or printed.
CHARACTERISTICS OF A COMPUTER SYSTEM
A typical electronic computer has the following characteristics:
1. Electronic in nature - Data are represented in form of electrical pulses. Operation is electronic and basic components are also electronic e.g. integrated circuit
2. High speed - in the order of Nanoseconds (that is 10-9 of a second.)
3. High degree of accuracy, in the order of 10-15
4. Consistency - that is given the same set of input data, the same result will always be produced
5. Ability to perform repetitive operations without getting bored or fatigued
6. Could store information on a long term basis
7. Automatic control - once initiated, it could operate on its own, without human intervention, under the control of stored sequences of instructions called program
8. Flexibility and programmability
These characteristics have made computer to be very versatile in all human endeavours such as
scientific researches, weather forecasting, medicine, security systems, library system, language translations, classroom instructions, engineering design, payroll, billing, sales analysis, inventory, office automation and so on.
CLASSIFICATION OF COMPUTERS
Computer can be classified into various forms because of the complexity and diversification in its application. In this text, four basic classifications will be adopted.
These are classification according to generations, classification according to types, classification according to size and classification according to usage or functions.
Classification according to Generation
The industrial revolution during and after the 2nd world war was fully annexed by the stakeholders in information technology to fully actualize their dreams of having a very reliable computer, hence, the classification of computers into generations. There are five basic generation to which computer can be classified.
1. First Generation Computer:
These were the early computers that were manufactured in 1940's and last till 1950's. The first generation computers were characterized with the use of vacuum tubes as its major components. These vacuum tubes generate enormous heat and consume much electricity. The first generation computers introduce the concept of stored programs. Exclusively, computer experts can program the computer only in machine language, which makes it programmable.
Examples are UNIVAC, ENIAC etc
2. Second Generation Computer:
These were the set of computers that succeeded the first generation computers. Their advent was in early 1950's and the lasted until late 1950's. thecomponents of the second generation of computer were built around transistors which replaces the vacuum tube in the first generation. The resultant effect of the transistors in place of vacuum tube is reduction in size compare with first generation computers, less power consumption, generation of less heat and improved storage facility due to introduction of magnetic devices for storage medium. The overall effects are the improved reliability and introduction of symbolic languages for programming.
Examplesare ATLAS, IBM 1400 series, PDP I & II etc.
3. Third Generation Computer:
This generation of computer succeeded the second generation computers. The advent of this generation was between early 1960's to late 1960's. Due to the technological advancement that has taken place in the industrial sector which makes many transistors to be coupled into a single unit component.
Hence, the major component that characterized the third generation computer is the Integrated Circuitry (IC), which is a resultant effect of thousands of transistors combined into a single unit component. The integration of transistors into one component makes the computer smaller in size compare with first and second generation computers, faster machine, consume less power and generate less heat.
The concept of multi-programming was introduced in this generation of computer. Programming was made easier by the use
of high level languages.
Examples include: IBM 360/370 series, ICL 1900 series etc.
4. Fourth Generation Computer:
The emphasis in the first three generations of computer has been on the development of a computer system that is less expensive, more portable and highly reliable. The fourth generation computers were also developed having in mind the above assertions.
These generations of computers were built around Very Large-Scale Integrated Circuitry (VLSI) in which over ten thousand flip-flops were placed in a single silicon chip i.e thousands of ICs were combined into a single chip. These period witness the era of microcomputer with the introduction of microprocessors as its major
component. The system came into being in the early 1970's and still in existence till date.
Examples include: IBM, COMPAQ 2000 series, Dell series, Toshiba etc.
5. Fifth Generation Computer:
The development of the fifth generation computers started in the 1980's and classical researches are still going on in this generation of computers.
Although, some of these machines are already in use, but a lot of work still need to be done to actualize the reasons for this generation of computer. The objective of this computer system is to build a computer system that mimic the intelligence of human expert in a knowledge domain such as medicine, law, education, criminal investigation,
etc. This objective is achieved through the implementation of Artificial Intelligence and expert Systems development.
BASIC COMPUTING CONCEPTS
A computer can be described as an electronic device that accepts data as input, process the data
based on a set of predefined instructions called program to produce the result of these operations as output called information. From this description, a computer can be referred to as an Input Process-Output (IPO) system, pictorially represented in the figure below:
Input - Process -Output representation of a Computer System
Data is a piece of basic raw fact, such as a score in examination or the name of a student, for example 55 or Malik respectively. There are three types of data - Numeric, alphabetic, and alphanumeric. Numeric data consists of digits 0 - 9 (e. g. 31).
while alphabetic data consist of any of the English language alphabets (e. g. Toyin). An alphanumeric data can consist of a number, an alphabet or a special character, such as a vehicle plate number (e. g. AE 731 LRN).
Information: data as described above contain no meaning, however, when it is transformed into a more meaningful and useful form, it is called information. The transformation process involves a series of operations to be performed by the computer on the raw data that are fed into it. The operation can be arithmetic (such as addition, subtraction, multiplication, and division), logical comparison or character manipulation (as in text processing).
Logical comparison means testing whether one data item is greater than, equal to, or less than another item, and based on the outcome of the comparison, a specified action can be taken.
Theoutput of the processing can be in form of reports which can be displayed or printed.
CHARACTERISTICS OF A COMPUTER SYSTEM
A typical electronic computer has the following characteristics:
1. Electronic in nature - Data are represented in form of electrical pulses. Operation is electronic and basic components are also electronic e.g. integrated circuit
2. High speed - in the order of Nanoseconds (that is 10-9 of a second.)
3. High degree of accuracy, in the order of 10-15
4. Consistency - that is given the same set of input data, the same result will always be produced
5. Ability to perform repetitive operations without getting bored or fatigued
6. Could store information on a long term basis
7. Automatic control - once initiated, it could operate on its own, without human intervention, under the control of stored sequences of instructions called program
8. Flexibility and programmability
These characteristics have made computer to be very versatile in all human endeavours such as
scientific researches, weather forecasting, medicine, security systems, library system, language translations, classroom instructions, engineering design, payroll, billing, sales analysis, inventory, office automation and so on.
CLASSIFICATION OF COMPUTERS
Computer can be classified into various forms because of the complexity and diversification in its application. In this text, four basic classifications will be adopted.
These are classification according to generations, classification according to types, classification according to size and classification according to usage or functions.
Classification according to Generation
The industrial revolution during and after the 2nd world war was fully annexed by the stakeholders in information technology to fully actualize their dreams of having a very reliable computer, hence, the classification of computers into generations. There are five basic generation to which computer can be classified.
1. First Generation Computer:
These were the early computers that were manufactured in 1940's and last till 1950's. The first generation computers were characterized with the use of vacuum tubes as its major components. These vacuum tubes generate enormous heat and consume much electricity. The first generation computers introduce the concept of stored programs. Exclusively, computer experts can program the computer only in machine language, which makes it programmable.
Examples are UNIVAC, ENIAC etc
2. Second Generation Computer:
These were the set of computers that succeeded the first generation computers. Their advent was in early 1950's and the lasted until late 1950's. thecomponents of the second generation of computer were built around transistors which replaces the vacuum tube in the first generation. The resultant effect of the transistors in place of vacuum tube is reduction in size compare with first generation computers, less power consumption, generation of less heat and improved storage facility due to introduction of magnetic devices for storage medium. The overall effects are the improved reliability and introduction of symbolic languages for programming.
Examplesare ATLAS, IBM 1400 series, PDP I & II etc.
3. Third Generation Computer:
This generation of computer succeeded the second generation computers. The advent of this generation was between early 1960's to late 1960's. Due to the technological advancement that has taken place in the industrial sector which makes many transistors to be coupled into a single unit component.
Hence, the major component that characterized the third generation computer is the Integrated Circuitry (IC), which is a resultant effect of thousands of transistors combined into a single unit component. The integration of transistors into one component makes the computer smaller in size compare with first and second generation computers, faster machine, consume less power and generate less heat.
The concept of multi-programming was introduced in this generation of computer. Programming was made easier by the use
of high level languages.
Examples include: IBM 360/370 series, ICL 1900 series etc.
4. Fourth Generation Computer:
The emphasis in the first three generations of computer has been on the development of a computer system that is less expensive, more portable and highly reliable. The fourth generation computers were also developed having in mind the above assertions.
These generations of computers were built around Very Large-Scale Integrated Circuitry (VLSI) in which over ten thousand flip-flops were placed in a single silicon chip i.e thousands of ICs were combined into a single chip. These period witness the era of microcomputer with the introduction of microprocessors as its major
component. The system came into being in the early 1970's and still in existence till date.
Examples include: IBM, COMPAQ 2000 series, Dell series, Toshiba etc.
5. Fifth Generation Computer:
The development of the fifth generation computers started in the 1980's and classical researches are still going on in this generation of computers.
Although, some of these machines are already in use, but a lot of work still need to be done to actualize the reasons for this generation of computer. The objective of this computer system is to build a computer system that mimic the intelligence of human expert in a knowledge domain such as medicine, law, education, criminal investigation,
etc. This objective is achieved through the implementation of Artificial Intelligence and expert Systems development.
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