TOPIC 1
INTRODUCTION TO INFORMATION COMMUNICATION TECHNOLOGY
Introduction
A computer is an electronic device that takes in data and instructions (input), works with the data (processing), and produces information (output).
Basic Terms
Data refers to the raw facts that are fed to a computer.
Information is data that has been processed and can be used for decision making.
Data and Information can take either of the following formats:
•Text – These are number, characters or special symbols. They are used when preparing reports, letters, etc.
•Graphics – These are images. Used when preparing charts, graphs, pictures
•Multimedia – These are audio and video recordings that may or may not combine of text and graphics.
Processing is the act of converting data into information.
A typical personal desk top computer
History and Development of Computers
Overview
Nothing epitomizes modern life better than the computer. For better or worse, computers have infiltrated every aspect of our society. Today computers do much more than simply compute: supermarket scanners calculate our grocery bill while keeping store inventory; computerized telphone switching centers play traffic cop to millions of calls and keep lines of communication untangled; and automatic teller machines (ATM) let us conduct banking transactions from virtually anywhere in the world. But where did all this technology come from and where is it heading? To fully understand and appreciate the impact computers have on our lives and
promises they hold for the future, it is important to understand their evolution.
Five Generations of Modern Computers
First Generation Computers – 1940-1956: Vacuum Tubes
These computers used vacuum tubes for circuitry and magnetic drums for memory, were enormous, taking up entire rooms. Data Input was based on punched cards and paper tape. The UNIVAC and ENIAC computers are examples of first-generation computing devices.
A Photograph of ENIAC Vacuum tube
First generation computers were characterized by the fact that operating instructions were madeto-order for the specific task for which the computer was to be used. Each computer had a different binary-coded program called a machine language that told it how to operate. This made the computer difficult to program and limited its versatility and speed. Other distinctive features of first generation computers were the use of vacuum tubes (responsible for their breathtaking size) and magnetic drums for data storage.
Second Generation Computers (1956-1963):Transistors
The 1959 to 1963 era saw the development of the second generation of computers. This was the time when transistors were developed and introduced in to the internal circuitry of the computer thus replacing the vacuum tubes.
A transistor is a signal bridge that amplifies and transmits electronic signal from one point to the other. The transistors were smaller than vacuum tubes and this greatly reduced the overall size of computer. The transistors produced less heat and therefore failed less frequently. The computer therefore became more reliable, smaller in size and significantly faster than first generation computers.
Third Generation Computers (1964-1971):Integrated Circuits
Though transistors were clearly an improvement over the vacuum tube, they still generated a great deal of heat, which damaged the computer’s sensitive internal parts.
The development of integrated circuit chip •Transistors were miniaturized and placed on silicon chips, called semiconductors. This Increased the speed and efficiency of computers. It is important to note that Instead of punched cards and printouts, input was done through keyboards
and monitors.
They also used an operating system, which allowed the device to run many different applications at one time. Computers became accessible to a mass audience because they were smaller and cheaper than their predecessors.