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INTRODUCTION TO COMPUTERS
COMPUTER
โA computer is a machine that takes instructions and performs computations based on those instructions.โ CHARACTERISTICS OF COMPUTERS: The important characteristics of computer are as follows: i. Speed: โ
Computers can perform millions of operations per second. โ
The speed of computers is usually given in nanoseconds and picoseconds.
- Where 1 nanosecond= 1 x 10-9 and 1 picosecond = 1x 10- 12 ii. Accuracy: โ
A Computer is very fast, reliable and robust electronic device. โ
It always gives correct results, provided correct data and a set of instructions are input. โ
The output generated by the computer depends on the given instructions and input data. If the input data is wrong then the output will also have errors. (garbage-in and garbage out or GIGO) iii. Automation: โ
Computers are automatable devices that can perform a task without any user intervention. โ
The user just needs to assign the task to the computer after which it automatically controls different devices attached to it and executes the program instructions. iv. Diligence: โ
Computers never get tired of repetitive tasks. โ
It can continuously work for hours without creating errors. โ
Even if a large number of executions need to be executed, each and every execution requires the same duration and is executed with the same accuracy. v. Versatile: โ
Computers are used in daily life in all fields, for example, they are used as personal computers, for business-oriented tasks, weather forecasting etc. โ
Therefore, computers are versatile devices as they can perform multiple tasks of different nature at the same time. For ex: on personal computers used at home you can play games or send emails or even listen to music.
vi. Memory: โ
Computers have internal or primary memory as well as external or secondary memory. Computer stores large amount of data and programs in the secondary storage space. The stored programs can be used whenever required. โ
Internal memory of computers is very expensive and limited in size, secondary storage is cheaper and of bigger capacity. โ
When data and programs are to be used, they are copied from the secondary memory into the primary memory (RAM). vii. No IQ: โ
Trend today is to make computers intelligent by inducing AI(Artificial Intelligence) in them. โ
They still do not have any decision-making abilities of their own. They need guidance to perform various tasks. viii. Economical: โ
Computers are considered as short-term investments for long-term gains. โ
Using computers also reduces manpower requirements and leads to efficient way of performing various tasks. Hence computers save time, energy and money. โ
Computers can do more work in less time. STORED PROGRAM CONCEPT: Features: โ
Before any data is processed, instructions are read into memory. โ
Instructions are stored in the computer's memory for execution. โ
Instructions are stored in binary form. โ
Processing starts with the first instruction in the program, which is copied into a control unit circuit. โ
Instructions written by the users are performed sequentially until there is a break in the current flow. โ
Input/output and processing operations are performed simultaneously. Types of Stored Program Concepts: โ Computer with Von Neumann Architecture (fig 1.29(a)) stores data and instructions in the same memory.
Used for: scientific and commercial applications Examples: Honeywell 400, IBM 7030, CDC 1604 Highlights: Faster, smaller, cheaper and easier to use than first generation computers. โ
Third Generation (1964-1975) Hardware Technology: manufactured using integrated chips (ICโs). Minicomputers came into existence. Memory: large magnetic core memory; large capacity magnetic tapes; magnetic disks were used to store data and instructions. Software Technology: high level programming languages- pascal etc. (Time sharing OS was used) Used for: scientific, commercial and interactive online applications Examples: IBM 360/370, PDP-8, PADP-11, CDC Highlights: Faster, smaller, cheaper and easier to use than second generation computers. โ
Fourth Generation (1975-1989) Hardware Technology: manufactured using integrated chips (ICโs) with large scale integrated and later with VLSI technology. Microcomputers came into existence. Memory: semiconductor memory; large capacity magnetic disks(for secondary memory) and magnetic tapes and floppy disks were used. Software Technology: high level programming languages-C and C++, GUI, UNIX Used for: scientific, commercial, interactive online and network applications Examples: IBM PC, Apple II, CRAY-I, CRAY-II Highlights:
Faster, smaller, cheaper, powerful, reliable and easier to use than previous generation computers. โ
Fifth Generation (1989-present) Hardware Technology manufactured using integrated chips (ICโs) with ultra large scale integrated and later with VLSI technology. Use of internet became widespread and very powerful mainframes, desktops, smartphones, portable laptops. Memory: semiconductor memory; large capacity magnetic disks(for secondary memory) and magnetic tapes and floppy disks were used as portable storage devices.(now replaced with USB flash drives) Software Technology: high level programming languages-JAVA, Python GUI, UNIX, LINUX, Ubuntu Apple Mac Used for: scientific, commercial, interactive online, network and multimedia (graphics, audiovideo) applications Examples: IBM Notebook, Pentium PCโs etc.. Highlights: Faster, smaller, cheaper, powerful, reliable and easier to use than previous generation Computers. APPLICATIONS OF COMPUTERS:
- When the first computers were developed, they were used only in the fields of mathematics and science.
- Later on, computers were used in real-time control systems, like for landing on the moon. However, with the advancement of technology, the cost of computers and their maintenance declined.
- Today, computers are widely used in fields such as engineering, health care, banking, education, etc. โ Word processing: โ Word processing software enables users to read and write documents. โ Users can also add images, tables, and graphs for illustrating a concept.
โ Health care The following are areas in which computers are extensively used in the health care industry. โ Storing records: To begin with, computers are first and foremost used to store the medical records of patients. Earlier, patient records were kept on paper, with separate records dealing with different medical issues from separate healthcare organizations. โ Surgical procedures: Computers are used for certain surgical procedures. They enable the surgeon to use computer to control and move surgical instruments in the patientโs body for a variety of surgical procedures. โ Better diagnosis and treatment: Computers help Physicians make better diagnoses and recommend treatments. Moreover, computers can be used to compare expected results with actual results in order to help physicians make better decisions. โ Geographic Information System and Remote Sensing โ A geographic information system (GIS) is a computer-based tool for mapping and analysing earthโs features. โ It integrates database operations and statistical analysis to be used with maps. GIS manages location- based information and provides tools for display and analysis of statistics such as population count, types of vegetation, and economic development opportunities. โ Such type of information helps to predict outcomes and plan strategies. โ Remote sensing is the science of taking measurements of the earth using sensors on airplanes or satellites. These sensors collect data in the form of images, which are then analysed to derive useful information. โ Meteorology โ Meteorology is the study of the atmosphere. โ This branch of science observes variables of Earthโs atmosphere such as temperature, air pressure, water vapour, and the gradients and interactions of each variable, and how they change over time. โ Weather forecasting: It includes application of science and technology to predict the state of the atmosphere (temperature, precipitation, etc.) for a future time and a given
location. โ Aviation meteorology: Aviation meteorology is impact of weather on air traffic management. It helps cabin crews to understand the implications their flight plan as well as their aircraft. โ Agricultural meteorology: Agricultural meteorology deals with the study of effects of weather and climate on plant distribution, crop yield, water-use efficiency, plant and animal development. โ Nuclear meteorology: Nuclear meteorology studies the distribution of radioactive aerosols and gases in the atmosphere. โ Maritime meteorology: Maritime meteorology is the study of air and wave forecasts for ships operating at sea. โ Multimedia and Animation โ Multimedia and animation that combines still images, moving images, text, and sound in meaningful ways is one of most powerful aspects of computer technology. โ We all have seen cartoon movies, which are nothing but an example of computer animation. โ Legal System โ Computers are used by lawyers to shorten the time required to conduct legal precedent and case research. โ Lawyers use computers to look through millions of individual cases and find whether similar or parallel cases have been approved, denied, criticized, or overruled in the past. โ This enables the lawyers to formulate strategies based on past case decisions. Moreover, computers are also used to best track of appointments and prepare legal documents me for filling cases. โ Retail Business Computers are used in retail shops to enter orders, calculate costs, and print receipts. They are also used to keep an inventory of the products available and their complete description. โ Sports In sports, computers are used to compile statistics, identify weak players and strong
Computers help managers to analyse their organizationโs data to understand the present scenario of their business, view the trends in the market, and predict the future of their products. Managers also use decision support systems to analyse market research data, to size up the competition, and to plan effective strategies for penetrating their markets. โ Expert Systems Expert systems are used to automate the decision-making process in a specific area, such as analysing the credit histories for loan approval and diagnosing a patientโs condition for prescribing an appropriate treatment. Expert systems analyse the available data in depth to recommend a course of action. A medical expert system might provide the most likely diagnosis of patientโs condition.
