Chapter 1 Introduction and evolution of
computer
Computer is
defined as an electronic, digital, automatic machine which receives input from
the user through input devices as keyboard, mouse, processes it by processer,
store it if necessary in storage devices (RAM: primary/HDD: Secondary) and
gives the meaningful output in desired format through output devices such as
printer, monitor, etc.
In short, it
is defined as a machine that processes the data and gives meaningful output
according to instruction given by user.
Features:
1.
Speed and size
2.
Vast storage
capacity
3.
Diligence
4.
Versatile
5.
Automatic
6.
Accuracy
7.
Reliability
8.
Electronic
9.
Non-intelligence
10.
Communication
Capabilities
1) Provides faster and cheaper means of
communication
2) Has a very huge storage capacity
3) 100% efficient and accurate jobs are
performed by it
4) Works 100 times faster than human
beings
5) Can perform such tasks which is
impossible for humans
Limitations
I.
does
nothing without the information provided by user so it’s a dull machine
II.
electricity
is most to run
III.
literate
and technical person can only operate it
IV.
proper
maintenance is needed otherwise 100% accurate results are not observed
Basic terms used in computer
A. Hardware
Physical
parts of whole computer system which have got some shapes and sizes and also
touchable and seen are hardware. E.g. mouse, CPU, monitor
B. Software
Collection
of programs for performing specific task is known as software. It does not have
any shapes and sizes; neither can we see it but can feel it.
C. Command
The
instruction and order given by the user to the computer to do some specific
task. They depend on language we use but after all it is to be translated in
binary code.
D. Program
The
collection of instruction written in a sequential form and in a logical way is
program
E. RAM Random Access Memory
RAM is a
volatile primary memory device that stores data temporarily. Data are stored in
it till the system is working. It is directly connected with CPU
F. ROM Read Only Memory
ROM is a non-volatile primary memory device that stores data
permanently or semi-permanently. It is a computer’s memory in which all the
booting procedures are stored through computer system boots.
G. CPU Central Processing Unit
It is the
brain of the computer where all processing and operations are performed. It is
a brainless idiot servant
H. Data
It is a raw
material for information. It can be text, audio, video, images or their
combination. It is the initial form of information
i.
Primary
data
ii.
Secondary
data
I. Information
The outcome
of data or the result of processed data is information. True data is needed for
true information.
J. Memory
The place in
a computer system where data and information are stored permanently or
temporarily
i.
Primary
memory
ii.
Secondary
memory
RAM
|
ROM
|
1.
It is volatile
memory
|
It is non-volatile memory
|
2.
RAM is loading
memory
|
ROM is boot-up memory
|
3.
It is user’s
memory
|
It is computer’s memory
|
4.
It is little
expensive
|
It’s cheaper than RAM
|
Memory chart
Application fields of computer
I.
Home
II.
Office
III.
Banking
IV.
Business
enterprises
V.
Education
VI.
Research
and engineering
VII.
Simulation
VIII.
Misiel
guiding
IX.
Weather
forecasting
X.
Communication
XI.
Transportation
XII.
Entertainment
XIII.
Software
making
XIV.
Film
making
XV.
Advertisement
XVI.
Health
XVII.
Medical
science
History of computer
Father of computer science: Charles Babbage
Charles
Babbage invented analytical engine in 1842 A.D. which consisted of 4 components
such as store (memory), the mill (CPU) input selection (using punch card) and
output selection (using punch card) which we use in our modern computers
