computer generations



  Basic of Computers

  by

  Alexander Stone

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  PUBLISHED BY:

  Basics of Computers

  Copyright © 2010 by Alexander Stone

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  CHARACTERISTICS AND LIMITATIONS OF

  COMPUTERS

  There are many kinds of computers in the world today but their basic functions are usually the same and hence, the competition is stiff. We might find it easy to adjust

  to a person who has contracted some incurable deformity, but a computer with irreparable deformity of malfunctions becomes an outdated and useless machine, which is subsequently pushed aside and ignored for some better machine. If the thinking, talking and reasoning powers make a human being different from other living creatures, what makes a Computer so special?

  Let us first compare the computer with another similar but less versatile calculating machine viz-the Calculator. Almost all of us have seen a calculator, if not a computer. They are used extensively at any place dealing with a fair amount of calculations.

  CALCULATOR

  COMPUTER

  1. Electronic/Mechanical.

  1. Electronic/Automatic.

  2. Performs mathematical calculations

  only.

  2. Performs mathematical and

  logical operations.

  3. Operates at a high speed.

  3. Operates at an incredibly high speed.

  4. Small temporary memory.

  4. Large temporary memory.

  5. No facility for a secondary storage

  device.

  5. Facility for large secondary storage

  devices.

  6. Needs an operator continuously.

  6. Once initiated, is capable of functioning

  automatically.

  7. Handles small and uncomplicated

  calculations.

  7. Handles volumes of simple and highly

  complex operations.

  CHARACTERISTICS OF A COMPUTER

  So we see, that to define a computer merely as a calculating device is to ignore 80% of

  its functional capabilities which include non-mathematical and non-numeric operation

  as well. The major characteristics that make the computer such a powerful machine can be enumerated as speed, storage, accuracy, ability to operate automatically, diligence, scientific approach, versatility and connectivity and networking. Let us look at each of these characteristics briefly:-

  SPEED

  Just as we can measure the speed of moving device e.g. a car traveling in terms of

  Km/hours or Miles/hours, the speed of a computer too can be measured.

  This speed however is incredibly faster than what man can possibly record or calculate normally. The computer’s speed at performing a single operation can be measured in terms of milliseconds (A thousandth of a second or 10-3), microseconds (A millionth of a second or 10-6), nanoseconds (A thousand millionth of a second or 10-9), picoseconds (A million millionth of second or 10-12).

  They are also mentioned sometime as Kilo Instructions Per Second (KIPS), Million Instructions Per Second (MIPS) and Trillion Instructions Per Second (TIPS), etc. Further, the most popularly used units of speed in Personal Computers are MHz and GHz (i.e. related to clock frequency).

  STORAGE

  One of man’s failings is perhaps his inability to remember and ‘store’ large volumes of

  Information is his brain. The computer is capable of overriding this deficiency as it can store

  a) Larger volumes of information being processed simultaneously within its own temporary memory, and

  b) larger volumes of data to be maintained more permanently on secondary media, such as – floppy disks, magnetic disks and tapes, punched cards, microfilms, Hard Disks, Mini Hard Disks (external), CD-ROMs, DVD-ROMs, Pen Drives, Zip Drives, MO Drives. etc.

  The storage capacity of any media or item can be measured in terms of certain units. e.g. a 1 litre bottle or a 5kg sack or a 1500 cubic litre water tank etc. The storage capacity of a computer is measured in terms of Bytes, Kilobytes and Megabytes, Gigabytes and Terabytes.

  BIT - Binary digit i.e. 0 and 1

  Byte - A string of fixed no. of bits is one Byte but in general 8