COMPUTER FUNDAMENTAL
DATA AND INFORMATION
1. What is
data?
Data is fact any character number or special character
such as:- 2, 3, 5, +, -, *, &, %, $ etc.
Example - Name
address, Age is facts related to people
Data
can be of three types:-
(a)
Alphabetic - a, b, c, d.........
(b)
Numeric - 1, 2, 3, 4, 5, 6, ..................
(c)
Alpha numeric - ab52, 52ac
2.
What is Process?
Work is done on data according to
the work on programmer is known as process.
3. What is Information?
Information means data in better
form that is in the form we want it for daily use.
Such as:-
When we
require the name of the student, name of subjects and marks obtained by him in
these subjects.
AVANTAGE OF A COMPUTER
The computer one of the most
powerful machines produced by man provides the following advantage.
1. Speed: - The computer is capable of performing calculation at
very high speed and generator complex result. Data stored in the files can also
be retrieved at a very high speed.
2. Reliability: -
The computer performs repetitive jobs without making any mistakes and without
getting tired. Human beings can make they can get tired.
3. Versatility:
- The. computer can be used for a
variety of jobs calculation, data retrieval, controlling machines,
entertainment.
Evolution
of computer
The word computer is derived
from the word "compute" which means to "calculate".
·
If
we look back at the history of computer it can be tracked back 3000 B.C. The
stone age man used small round stones (pebbles) for counting cattle.
·
Later
a device called abacus was developed by Chinese. This is supposed to be the
first mechanical computing device.
·
In
1647, John Napier, a Scottish mathematician developed a devices which is called
Napier's bones. With the help of these devices, multiplication and addition
were possible.
·
In
1642, Blaise Pascal, a French mathematician invented the first mechanical
calculator.
·
In
1673, Gottfried wilhelm Leibniz, A German invented the Leibniz calculator which
was word for addition, Subtraction and multiplication.
·
A
French weaver's sun named joseph marie jachquard made the next significant
contribution in 1804. After observing his father making different weaving
patterns on the loom, he thought of storing these patterns for future use so
the developed a plate with multiple holes to control the weaving pattern, not knowing
that one day his idea of storing the weaving patterns would be used to store
data and would called the punch card.
·
A
punched card is a thin rectangular card be divided into so columns and 12 rows
in which the various characters could be represented by punching holes in
different rows and columns. One character per columns, thus it is possible to
store so characters of data.
·
Around
1822, charle's Babbage a professor of mathematics a the combridge university
devised an automatic calculating machine called difference engine.
·
The
next significant invention came from Dr. Herman Hollerith, an Americans
Hollerith built a computer to analyze the census data of the united states of America
·
Howard
Alken, build the first fully electro mechanical computer named Mark-1
·
In
1945, a significant contribution was made by john Von Neumann, a Frenchman
working for IBM. He designed the basic structures of a computer to included the
capacity to :
1. Perform Logical Functions.
2. Perform Repetitive Functions.
3. Store data and instructions (Memory).
In 1945, the fully
electronics computer named ENIAC was build by prosper FCKERT and John W mauchly
ENIAC stands for electronic numerical integrator and.calculator.
The above three capacities also forms the
major differences between a calculator (which is also used calculations) and a
computer.
The computer has built in logic, the
capacity to make a selection. Logic means some rational thinking like, 2 is
bigger than 1.
The computer is capable
of ITERATION OR REPETITION Suppose,
you have to calculate interest for 100 fixed deposit accounts, in a computer
the instructions are stored only once, and these instructions can be executed
automatically, any number of times.
The data and instruction can be stored and retrieved using the
computer.
GENERATION OF COMPUTER
Now, in order to have
these three features i.e perform logical functions, perform repetitive
functions and store data and instruction (Memory) in a computer, certain
components were made use of which made a lot of difference in the capacity of
the computer. so depending on the technology of the computer are said to belong
to different generation.
Ø 1st Gen computers (1945-1955):- The main component in use was the vacuum tubes (like those
in the old radios, which warned up after a minute or so, and glowed red). The
vacuum tube was also called as various.
The first computer used
1700 vacuum tubes, weighed 30 tons and occupied an area of big hall. Vacuum
tubes or valves took age to warm up and consumed massive amounts of electricity.
Some of the computers of this generation are ENIAC, UNIVAC-1.
Ø 2nd Gen computer (1955-1965) :- The real break through in computers stared with the
discovery. In this generation to used of transistor a smaller an more reliable
successor to the vacuum tube was invented in 1947. The second generation
emerged with transistor being the brain of computer.
Ø 3rd Gen computer (1965-1970):- The second generation computers were well suited to do
either scientific or non-scientific applications but not both. Thus, in 1964,
in IBM announced the system 360 family of mainframe. Where each processor had a
set of large build in instruction. Some of these instruction could be used
effectively for scientific calculation while the other were more suited for
record keeping applications, The computers in this generation used the
technology of integrated circuits (IC). Since the ICs were small in size, there
was a further reduction in size of these computers.
Ø 4th Gen computer (1970-1975):- In this generation work on IC and there in integration
technique. In this generation which become Microprocessor but we invented to
fabricate the various transistor and IC. To compare the third generation
computer these were most reliable miniature in size having all most list heat
generating component fast in speed.
Ø 5th Gen computer (1975 yet to come):- yet to come: - In fifth generation term artificial
intelligence logical inference and speed recognition become the base of fifth
generation AI in turn of fourth generation will be the ability of system to
respond to natural language input they launch the project in 1981 company
research of (VLSI) Very large Scale Intelligence) logical programming knowledge
base system, pattern recognition.
Understanding a computer System
The application areas of computers are unlimited. We find a
computer in very aspect of our life. From a simple operation as playing a video
game to more complicated applications as weather forecasting computers are
found everywhere. Let us take a simple example of a person who needs to
purchase a can of juice from proceeds to the cash counter. The counter person
scans the code that is present in the label to generate a bill. This scanning
of the code is computerized. The man pays his bills with his credit card and
walks off the super market. He just used a computer, which will transfer the
cost of the can of juice from his bank account to the super market. The man
then moves across the street and enters the office of his travel agent. The
tells the agent that he plans to take a vacation and inquires about the places
that he can possibly go. The agent turns to his computer, presses a couple of
keys and gets the list of the prospective places immediately. The agent just
used a database application of the computer. The man selects a place and
confirms his travel. The agent again turns to his computer and moments later
hands him the air tickets to that place. The agent actually connected to a
computer that did the reservation. The man then happily comes to his office and
decides to inform his wife about the vacation. He, therefore, sends e-mail to
his wife. The man used a network application of the computer. Numerous examples
of such kind can be sited. With the advent of technology, newer and newer
application domains of the computer are created everyday. It is just a matter
of time when life without computers cannot be imagined.
What is a computer system?
Computer is an
electronics device which accepts data and performs calculation give output in a
meaningful manner.
Types of computer
Computer can either be
classified on the basis of purpose they serve (cater on the basis of size too)
into following three classes:-
1. Analog Computer
2. Digital Computer
3. Hybrid Computer
Analog Computer:- A computer in which continuous physical variable are
processed and represented in the form of data is known as analog computer. It
is an early type of computer which was designed to obtain data directly from
measurable quantities and process them, such as resistance, voltage, current,
temperature, speed, acceleration, deceleration etc. The input numbers are
represented by varying a physical quantity. A good example of analog device may
be clock with arms representing hours, minutes and seconds.
The quantities represented by analog devices may be termed as
analog quantities. A device is needed to convert these analog quantities into
digital is known as Analog to Digital Converter.
Digital Computer:-
A computer in which data
held as number of discrete or distinctly separate item is manipulated by
arithmetical /logical operations is said to be digital computer. These are
capable of representing data by producing and sensing discrete or off states
represented by binary digits '0s' and '1s'. A good example of digital device
may be digital clock.
Hybrid computers:-
Hybrid computers are
designed and developed by combining feature of analog and digital computers.
They can accept a varying input and convert it for digital processing. Recently
a hybrid computer has been designed and build for line calls in tennis matches.
This device senses whether the ball has dropped on the boundary line, within
boundary line or outside it. After sensing the spot where the ball bounced, it
processes the discrete data and displays the actual distance from boundary
line, reprocesses the same and displays the logical results on LCD (Liquid
Crystal Display) screen of personal computer or hand held palm top computer.
Digital computer is divided into four types:-
(a) Micro computer
(b) Mini computer
(c) Main frame computer
(d) Super computer
Micro computer: - It is a fairly small computer build around a microprocessor
and associated storage & input/output components. Most microcomputers are
single user oriented. However, multi-User oriented micro computers have been
developed. These are mostly desktop sized in which additional units or
peripherals may be attached. Most microprocessors produced in 1970s were 4 bits
or 8-bit machine and within 15 years 32 bit microcomputers had been designed
with almost equivalent feature of late 1970s mainframe computer systems. Microcomputer
has networking features through special microcomputers. Research and development
made possible to reduce the size and enhance the performance, speed, capacity,
networking features etc. This made them truly portable.
Ex: - Laptop computer, notebook
computer, palmtop computers etc.
Mini computer: - It is microcomputer overlap with features of mini computers.
It varies in size from desktop to a file cabinet with on line storage capacity
than pc (for multi-user environment) with ability to support greater variety of
peripheral devices. These are also known as ‘Midrange Computer’. Most minis
produced in 1970s faced challenging microcomputers developed with equivalent
and advanced features. Mini computers adopted distributed computing and multi-user
concept. In distributed computing concept, number of small computers is
distributed in organization offering central computing facilities’. In multi-user
computing concept, number of users can use computer in time sharing basis at a
time. Some example of minicomputers are NCR
32/800, ICL -101, VAX 8800 etc.
Main frame computer: - These are even more powerful than minicomputer. The features
of large mini and small mainframe may overlap in cost as well as in
performance. It may have large on-line storage capacity for multi-user environment
with high speed processing, complex data handling and centralized computing
capability. Some example of mainframe computers are Unisys 2200/600, IBM Systems/390, IBM
Systems/370, IBM Systems/360 etc.
Super Computer: - Super computer with sophisticated hardware are large in
size, have extraordinary processing speeds and designed altogether for
different type of processing capabilities known as parallel processing. The
speed of super computer is in MFLOPS, GFLOPS or TFLOPS.
1 MFLOPS= 1 Million Floating Pointing operation per second.
1 GFLOPS= 1 Giga
Floating Pointing operation per second.
1 TFLOPS= 1 Tera Floating
Pointing operation per second.
Some example of the super
computer is Cry-XMP, Cray-2, ETA-10, PARAM etc. PARAM was designed and
developed in India
HARDWARE
Computer system
Computer System is a
group of parts that are integrated to achieve some objective. A group of parts
or components of a computer system are:-
(a) Hardware
(b) Software
(c) Liveware
Simple grouping of above
components are of no use until and unless they are integrated logically in
order to accomplish a set of specific objective. Thus all these are logically
inter related.
Hardware
Computer hardware is defined as a set of physical components
and devices used in conjunction with these components that make up a computer
system. These physical components and devices can be visualized or sensed by
touching. A computer system generally consists of following components:-
(a) Central Processing Unit(CPU)
Control Unit
Memory
Arithmetic Logic Unit (ALU)
(b) Peripherals
Input Devices
Output Devices
Mass storage Devices
(c) Power Supply
SOFTWARE
Computer software is defined as a set of sequenced
instruction that controls operation of a computer to accomplish a set of
specific objectives. Software may be pre-written or custom-made. We will study
software in the next chapter.
LIVEWARE
Liveware is a jargon for
the people running computer systems. Liveware is the most important component
of computer systems. Liveware, or human ware, or people running computer are
the basic coordinating components who work together to determine processing
needs, provide input data, select hardware and software, design processing
procedure and use the processed output. People running computers may include
executives, Managers, system Analysis, software/Hardware English, Data entry
operation/computer operators etc.
Computer.' hard ware' and 'soft ware' are the most commonly
used terms in computer science an Computer science and represent inter- related.
aspects. One can do nothing useful with computer Hardware alone or with
computer software by itself. We will discuss software later in next chapter. This
chapter is depicted to computer hardware.
§ ANATOMY OF COMPUTER
Recalling
Charles Babbage's Analytical Engine, we find that its anatomy is quite
analogous to the anatomy of the modern computer. Theoretically you must know
the entities of computer system common for all types of typical computer. It
can be evidenced by the following block diagram of computer components.
Flow of Instructions
Flow of control
As discussed above in the definition
of hardware, we find that the basic organization comprises of following three
entities:
a.
Central
Processing Unit (CPU)
b.
Peripherals
c.
Power
Supply Unit
Central Processing Unit
(CPU)
Central Processing Unit is the electronic brain of computer
system and its following parts help it to perform the electronic thinking
process:
a.
Control
Unit
b.
Memory
Unit
-
Main
memory unit
-
Auxiliary
memory unit
c.
Arithmetic
& Logic Unit
d.
Busbar
System
Finally, as a heart of
computer system, it performs the following major operations:
a.
Accepts
data/instructions from input device.
b.
Stores
programmed instructions and data.
c.
Controls
the sequence of operations.
d.
Controls
the transfer of information amongst storage device, input devices, output
devices etc.
e.
Performs
the Arithmetical & Logical operations according to instructions
f.
Sends
results/data to output devices.
Control Unit
This unit consists of circuitry which looks after operations and
activities of every component of CPU and other related parts .it controls and
co- ordinates all hardware operations.
It performs the following
major functions:
Þ Controls flows of data form input
devices to memory (main or auxiliary) or to ALU. It further controls flow of
resultant data form ALU to memory and to output devices.
Þ Controls the function of storing program
in the memory takes step by step instructions, interprets them and controls
other hardware components, synchronizes and co-ordinates then according to
programmed instructions or instructions provided through input devices.
Memory units
Before stepping in the world of memory units lets us see what
is computer memory and basics of computer operation
Memory is a device or media that can accept, store and
deliver data on demand and consists of magnetic cores or semiconductor devices.
Not only computer memory, all parts of computer understand
and work on 1s and 0s or binary system. Binary
system is also known as 'base two system'.if you would have an in de like to have an in depth knowledge of
various numbering system you may go through "Number Systems and Codes used
in computers.
There are two types of memory.
(a) Random Access Memory (RAM)
(b) Read Only Memory(ROM)
Random Access Memory (RAM)
Random
Access Memory is a storage device where in time required to retrieve data is
independent of the physical location of data. It is a volatile sort of memory
because it loses its contents when the computer is switched off or at the time
of power failure fluctuation. It is also known as temporary memory due to its
characteristics. Computer can read, write and erase information on them.
There are two types of RAM
a. Dynamic RAM(DRAM)
b. Static RAM(SRAM)
Dynamic RAM
It needs regenerator circuits to
retain stored date. These are used as primary memory in most computers.
Static RAM
These
are so designed that it does not need regenerator circuit to retain the data hence,
these are more complicated, costly and take more space for a given capacity
than dynamic RAM.
Read Only Memory (ROM)
Read
Only Memory often referred as ‘firmware’ is storage device which programmed
while manufacturing and can not be reprogrammed by computer user known as Read
Only Memory. It is also known as permanent memory due to its characteristics.
Normally, it contains information that is needed by CPU when you first turn
your computer ‘on’ as well as frequently when you use programs. A part of disk
operating system programmed resides in it which is needed to initialise or boot
your (BIOS). BIOS checks and tests hardware part of your system so that you may
be able to operate. The term ‘booting’ has been taken from boot strapping. It
is quite natural that before leaving or proceeding for somewhere you have to
wear and strap your boots.
Similarly, PC checks every part of
connected hardware and readies it with the help of initializing or boot strap
loader program.
It is non-volatile because it does
not loose its contents in the event of power failure/interruption. Now the
specific ROMs which can be programmed by experts with the help of special
hardware are being manufactured. We will not go in depth of ROMs as it is
beyond the scope of this book. Some of such ROMs are listed below:
a. Programmable Read only Memory(PROM)
b. Erasable and programmable Read Only
Memory(EPROM)
c. Electrically Erasable and.
programmable Read Only Memory
– Programmable Read Only Memory (PROM)
The Programs are written in to these
memory chips before assembling of
of computer according to the need.
– Erasable and programmable Read Only
Memory (EPROM)
Its contents can be erased
by ultra-violet light so that it can be re-used for other programs.
–Electrically Erasable and programmable
Read Only Memory (EEPROM)
With special electronic
pulses generated by EEPROM Programming equipments.
Most memory devices are
semiconductors/IC and they pack in more storage space, compact in size and have
faster performance than earlier storage units.
Memory units comprise of
two types of memories or storage devices.
a. Main Memory or Primary storage device
b. Auxiliary Memory or Secondary Storage
device.
Main Memory
It is known as primary storage Device
(PSD) OR Immediate Access storage Device (IASD) generally referred as RAM. As
per the block diagram it can be sub divided in to following components
according to its working.
(a) Program Storage Area
(b) Input Storage Area
(c) Working Storage Area
(d) Output Storage Area
Program storage Area
It stores the processing instruction
waiting to be obeyed or currently being obeyed by other components of CPU.
Input storage Area
It stores data awaiting processing.
Working storage Area
It stores data being processed and
its intermediate results which are further fed to output storage area.
It
stores processed data until it can be immediately released to output devices.
Thus, any data or instructions stored
in the main memory can be retrieved. at high speed. Which may be in nano
seconds, too. The main fact to be noted is that main memory provides and
retains space for instructions and data until the power supply. or program is
terminated i.e. on the temporary basis.
Another type of memory is ROM which
may be termed as intermediate memory on which certain basic functions necessary
for initialisation or booting purpose are permanently etched. It loads DOS from
bootable hard disk/ floppy disk.
Auxiliary Storage device
It
is also known as Secondary Storage device, Backing storage device or Extended
Storage Device. As discussed above the main memory stores information and data
on a purely.temporary basis. Auxiliary storage device fulfills the need or
storing data and information permanently which may be furtherer erased when not
needed. This may be further divided.in to.
(b) Off line auxiliary storage device
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