COMPUTER

COMPUTER

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A computer is a special multipurpose machine (electronic device), that is capable of receiving instructions (data), storing and processing it and giving a desired result as output accurately at an incredibly high speed.

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The Computer as a System is a set of inter-related components aimed at achieving the same goal. The Computer as a system is made up of:

Hardware

Software

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Hardware refers to the physical units or components, which makeup computer configuration. There are three major components of computer hardware namely; the processor, peripherals and auxiliary hardware,

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Software refers to the programs, which are processed by the hardware; they can be seen but cannot be touched. A program is a sequence of instructions that are carried out by the hardware to solve given problems or perform given tasks. Software is further divided into; System software and application software.

System software: These are suite of programs that come with the computer to assist in the use of the hardware. Examples are, utility programs, the operating system etc.

Application software: These are softwares that are designed to be put into specific practical use, they are capable of performing variety of tasks. Examples are CorelDraw, Opera mini Browser etc.

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DIGITALIZATION OF DATA

Data digitalization is the process by which physical and manual records such as text, images, video and audio are converted into digital forms.

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BENEFITS OF DIGITALIZING DATA

Long term preservation of documents

Orderly archiving of documents

Easy and customized access to information

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Examples of Input device include

Keyboard

Mouse

USB

Diskette

Joystick

Card Reader

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Examples of Output Device include.

Printer, Monitor, headphone

Speakers, Plotter, punched tape

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GENERATIONS OF COMPUTER

We have five generations of computer, each generation has better advancement than the previous, the various generation and their features are explained below:

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1st Generation: The period was (1946-1959), Made use of Vacuum tubes, very large in size, made a lot of noise, needed a big system because of the heat generated, Expensive and could only be maintained by a big corporation, slow input and output device (Slow processing speed), it needed A.C, consumed large electricity and supported machine language only . Examples of such computers were ENIAC, UNIVAC, EDSAC, IBM-650 etc.

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2nd Generation: The period was (1959-1965) Major component was transistor. Generated lesser heat, small in size, cheaper, faster, consumed lesser electricity and more reliable when compared to the 1st generation computers needed a.c rooms, programming language was machine and assembly language.

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3rd Generation: The period was (1965-1971), major components was integrated circuit, employed the small scale integration (SSI) technology; High level language were used, easy to use, smaller in size, consumed lesser electricity and faster than the 1st two generations. Examples were IBM-360 Series, PDP (Personal Data Processor), TDC-316 etc.

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4th Generation: The period was (1971-1980), component was microprocessor, small in size, employ the very large scale integration (VLSI) Technology, user friendly software and programming language is high level, very cheap, faster than previous generation, portable and reliable, no A.C needed, Examples were, CRAY-1, PDP 11, STAR 1000 etc.

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5th Generation: The period is (1980 - Till Date), uses Ultra large scale integration (ULSI) technology, although Artificial intelligence are still in development, most devices these days are still been produced using microprocessors, they have very small in size, easy to use, high processing speed, large storage capacity, intelligent, natural language advancement. Examples are; Laptop, Desktop, Palmtop etc.

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CLASSIFICATION OF COMPUTERS

It is virtually impossible to definitely categorize computers by size, cost or scope. Computers are generally classified based on;

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Size and speed of operation

Data Representation

Number of purpose

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Classification based on Size and speed of operation

In this class we have

Monster computer

Mainframe computer

Mini-Computers

Micro-computer

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Monster computer: They are computer systems with enormous power and size. They are the largest, fastest and most expensive of all computers. These are otherwise known as Supper or Maxi computers. E.g. CRAY X/Y

Uses:

They are used for scientific and military research

Used to track and control space exploration, for oil exploration, simulations and worldwide weather forecasting.

Mainframe computer: They are large computers that require specially weird air-conditioning room, they are capable of great processing speed and data storage, they are very expensive, they are used for storing large information’s and process large data within a short time. They have closed system Architecture

Mini computers: They are also known as medium/Mid range computers. They fall between Mainframe and Micro-computers in their speed and data storing capacities. They posses all feature of mainframe but at a lower capacity, they are cheap, have small memory and they need no complex management structure.

Uses

Organization used them for research and specific purposes.

Micro-computers: They are popularly known as micros. They are the smallest of others and micros got its name as a result of its main computing component (microprocessor) which is located on one integrated circuit or chip. They are built with expansion slot micro-computers are called personal computers because they are designed to only allow one user at a time though two or more computers can be linked in a network. Examples of micro computers are Laptop, Desktop, Palmtop etc.

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Classification based on Data Representation

They are basically

Analogue Computers

Digital computers

Hybrid computers

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Analogue Computers: This handles data in form of varying signal/quality that assume an infinite number of levels during variation. i.e It works by measuring changes in continuous physical or electrical state rather than counting. Such measurements as temperature, voltage, volume, chemical composition of petroleum products, amount of current flowing through an electric current etc, are used.

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Digital computers: This type processes data in discrete form i.e “ON or OFF”; YES/NO. They count numbers and can only produce integers (floating point numbers). All the input must be in “quantized” or integral form everything they do is translated into a series of numerals or digits. They process discrete numbers. Examples are Mainframe, Mini and Micro-computer.

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Hybrid computers: These are the type of computers that combine the functions of both Analogue and Digital signal/data using Analogue-Digital converter or vice versa and work as a single system. Thus, a Hybrid computer consists of an analogue and a digital computer functioning as a single computer.

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Classification According to Number of Purpose

Computers exist as special and general purpose.

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Special Purpose Computers: These were designed to perform one specific task such as scientific work, or word processing. The program of instructions is built into the `machine and this, once booted, goes straight to the configured mode. They have merit of performing the job economically, quickly and efficiently. They are also known as Dedicated Purpose Computers.

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Examples: Production control of Refinery and Guidance, control of Airplanes, weather study forecast, Automobile; Thermostat; microwave ovens, etc.

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General Purpose Computers: They are also called multi-purpose computers and are used for Variety of works, they have the ability to store various programs of instructions, perform a variety of operation such as integrated processing, graphics, database etc. Most computers are general-purpose machines as they can handle many and different kind of tasks of. Because, most Microcomputers are general purpose, they have multi-tasking capability.

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Assignment

Write a short note on the contribution of IBM and APPLE to the growth of computer industry.