INTRODUCTION TO
COMPUTING
Lecture No. 3
Lahore Leads University
22st October 2013
SHOULD SOFTWARE ENGINEERS AND CS&IT
PEOPLE WORRY ABOUT HARDWARE
Will start the lecture from the Point that we
have discussed in the Last Lecture, that
was “some students of computer and
information
sciences
look
computer
hardware the same way as Drivers look at
their cars”
 Yes it is a fact that to drive the use of a car
doesn’t require a driver to build one.
 Same is the case with you all, it might not
be vital to know the design and build a
computer but if you know the design it will
go a long way to improve your skills. It will
also help in your professional life. How? (On
next slide)

HOW?
It might be a case that someone of you will
go into a career that involve Computer
programming, Computer system design, if
that is the case the principle of computer
organization will provide you tools to
create better design. This will include:
1. System Design Tools:
The same design theories used at the
lowest level of system design are applied
to the higher levels. As an Example the
same method used by a circuit board
designer to interface between a processor
and memory chips are used to design the
addressing scheme of an IP Network

TOOLS TO CREATE BETTER DESIGN
2. Software Design Tools
The Same procedure used to optimize the
digital circuits can be used for the logical
portion of the software. As an example
complex blocks of if-else statement can be
used to simplify the design in order to
achieve a much quicker output.
3. Improved trouble shooting skills
If you completely understand the computer
you will have an edge to trouble shoot much
quicker than others. Think about it yourself
and you all will agree to that.
TOOLS TO CREATE BETTER DESIGN
(CONTINUED)
4. Interconnectivity
Hardware is needed to connect the real
world to the computers input and output.
You have to interface the device via ports. If
you understand the interfaces and the
programming mechanism you can easily
introduce interconnectivity.
5. Marketability
Embedded
system
design
puts
microprocessor
into
tasks
specific
applications. Processors are becoming
cheap on daily to daily basis.
AN EXAMPLE OF EMBEDDED SYSTEM
PROCESSOR DEVICE



GPS stands for Global Positioning System. It is
used to determine your geographical location.
In Europe one can use a device known as GPS
Device to find routes, locations. It is a task
specific device.
You can also find information on your
computers just by accessing “GOOGLE maps”.
The only issue will be that it will not be a real
time tracking if you want it to be a real time
tracker than you have to plug a device.
The purpose of this information is to let you
know that it is all about software development
that has made life easier for us.
AN EXAMPLE OF A DIGITAL SYSTEM
NON- DIGITAL SIGNALS
The real world is Analog. What does that
mean now? The answer to that is “An
analog value is equal to a floating point no.
having infinite number of values at the
right of a decimal point”
 Example is temperature, they don’t take
distinct values. Yes on your thermometer
you observe degree values like 99, 100 etc.
but in real world they take values like
99.987645.
 Another example is weight a Human Being
doesn’t exactly weigh 178 Pounds.

A REAL ANALOG SIGNAL

If the value is changing at every second
than the values are represented by a
continuous signal that is given below;
DIGITAL SIGNALS
There were computers called Analog
Computers that existed before.
 They used to process information on the
basis of levels of electricity or the positions
of mechanical devices.
 Modern computing don’t do this.
 Modern computing is digital, they convert it
to a number with a fix resolution means
that the digits to the right are fixed decimal
points instead of infinite value.

DIGITAL SIGNALS CONTINUED

The values are taken with respect to the
time. A table is given below that is
representing the Digital Values.
DIGITAL SIGNALS CONTINUED
Since the computer look at the world with a
fixed resolution in both time and
magnitude, when a computer records an
analog signal such as sound waves from
music, it does it by taking a sequence of
snap shots.
 You will find a signal on the next slide
demonstrating the sound wave. The
computer only measure at intervals. Each
measurement is called a sample. The rate at
which these samples are taken is called a
sampling rate

EXAMPLE OF SAMPLING
PROBLEMS WHILE SAMPLING
A CONVERSION SYSTEM
REPRESENTATION OF A DIGITAL SIGNAL
TYPES OF DIGITAL SIGNALS
We have already studied this in the last
lecture.
 Two types are Edges and Pulses.

SIGNAL WAVEFORM
COMPARISON OF TWO PULSES
SOME UNIT PREFIXES
PROBLEMS TO BE SOLVED
Define the term sample as it applies to the
digital system?
 Define the term sampling rate?
 What are the two primary problems that
sampling can cause?
 Name the three parts of the system used to
input an analog signal into a digital system
and describe their purpose?
 Name four benefits of a digital system over
analog system
 If a computer runs at 12.8 GHz, what is the
period of its clock signal?
