C(M)PE 101
Introduction to
Computing
Introduction
Computers in our lives

Can you name a business field that
does not use computing systems at all?
We live in an age of technology and a life without
computers is unthinkable now.
What is computer?

A computer is an electronic device that performs the
four basic operations that comprise the information
processing cycle.
(IPOS): Input, Processing, Output, and
Storage
IPOS Cycle

Input: The action of entering data.

Processing: The manipulation of the input data.

Output: The display of the information.

Storage: The action of saving information for
temporary or permanent usage.
Computer systems

Computer Systems are a variety of digital devices
(not necessarily personal computers) that are setup in a
way to communicate and perform tasks.

A computer system consists of :
1)
Hardware
2)
Software
3)
Data
4)
User
Hardware

Hardware refers to electronic and mechanical parts of the
computer.

The term hardware refers not only to the internal parts of the
computer but also its external parts.

The internal parts of the computer are called system units.
These are the essential parts needed for a computer system
to run.

The external part of the computer are called peripheral
devices. These can be added to a computer system to
expand what a computer can do.
Software

Software is a computer program that tells the
computer how to perform tasks.

There are many categories of software available for
computers and computer systems.

Generally however, these categories are over-simplified
into two main titles as system software and
application software.
Data

Data consist of individual facts or pieces of
information

A computer’s primary job is to process these tiny
pieces of data and convert them to useful
information. This task is called processing.
User

Users are people who use computer systems.

Using all its parts together, a computer converts data
into information by performing various actions on data.

The users enter the data and receives the processed
information as output.
History of Computers
Computers, then and now

Pre-Computers and Early Computers (before
1945)

First Generation - (1946-1957)

Second Generation - (1958-1963)

Third Generation - (1964-1970)

Fourth Generation - (1971-near past)

Fifth Generation - (Now)

Sixth Generation – (the future)
Pre-Computers and Early
Computers

The Abacus was among the earliest counting
devices. Believed to be invented by the
Babylonians between 500 B.C. and 100 B.C.

Gear-based machines (1600s-1800s)
Positions
of gears represent numbers
Pre-Computers and Early
Computers

Dr. Herman Hollerith’s Punch Card Tabulating
Machine and Sorter is an example of an early
computing device and was used to process the
1890 U.S. Census.
First Generation
Computers

First-generation computers were large and
bulky, used vacuum tubes, and had to be
physically wired and reset to run programs.

ENIAC (Electronic Numerical Integrator And
Computer) was the first electronic generalpurpose computer.
ENIAC
Second Generation
Computers

Second-generation computers, such as the IBM
System/360, used transistors instead of vacuum
tubes and were smaller, faster, and more
reliable.
Third Generation
Computers

The integrated circuit marked the beginning of this
generation allowing for smaller computers, like the
DEC PDP-8, the first commercially successful
minicomputer.
Fourth Generation
Computers

Fourth-generation computers, like the original
IBM PC shown here, are based on
microprocessors. Earlier computers fall into this
category.
In 1981 IBM introduced its first computer for the home user,
and in 1984 Apple introduced the Macintosh.
Fifth Generation
Computers

Computers we use today fall into this category
Sixth Generation
Computers

Artificial Intelligence (AI) is the future generation of
computers.
Computer Hardware
Fundamentals

Any device that has four basic functionality of a
computer can be regarded as a computer
system. In this case, remember that your
smartphone and your tablet devices are also
computer system.

The four basic functionality of a computer
system are: input, processing, output and
storage.
Computer Hardware (1)
Monitor
(output)
Processor
Speaker
(output)
Mouse
(input)
Keyboard
(input)
Computer Hardware (2)
Processor
Speaker
(output)
Touch Screen
(input & output)
Microphone (input)
Computer Hardware (3)
Processor
Microphone
(input)
Speaker
(output)
Touch Screen
(input & output)
Computer Hardware (4)
Touch Screen
(input & output)
Keyboard
(input)
Mouse
(input)
System Unit vs
Peripheral devices

The hardware that are essential for the computer to
run are called System Units. These include
Central Processing Unit (CPU), Arithmetic Logic Unit
(ALU) and related microchips and micro-circuitry.

Other hardware that can be plugged into the
motherboard
of
the
computer
are
called
peripheral devices. These include but not limited
to keyboard, mouse, speakers and digital cameras.
Motherboard

The motherboard is the physical foundation of computers
and computer systems.

A motherboard provides the electrical connections by
which the other components of the system communicate.

A typical desktop computer has its microprocessor, main
memory, peripheral devices and other essential
components connected to the motherboard
Components of
Motherboard

The following components are attached to the
motherboard:

Microprocessor sockets (one or more CPU)

Support Electronic Circuitry (Power Supply)

Memory Chips (RAM, ROM, Cache Memory)

A clock generator (for system clock signal to synchronize
various components)

Buses

Slots for expansion cards (interface to system via bus support)

Connectors (for hard drivers)

Power Connectors (to receive electrical power from power
supply)
Computer Software
Fundamentals

The software is the information that the computer
uses to get the job done. Depending on the platform,
there are many terms used for process of accessing
software : running, executing, starting up, opening,
and others.

Computer programs allow users to complete tasks. A
program can also be referred to as an application
(app) and the two words can be used interchangeably.
Computer Software

If we oversimplify, there are two major categories of
software:
1.
System Software – depends on hardware
2.
Application Software – depends on system
software
 Can
you give examples to both?
The Role of Algorithm

The most fundamental concept of CS is an algorithm.

An algorithm is a set of steps that define how a task
is performed.

A representation of an algorithm in a specific
programming language is called a program.

The process of developing a program, encoding it in
machine-compatible form, is called programming.
Bits and Data Storage

Inside Today’s computer systems, information is encoded as
patterns of 0s and 1s. These digits are bits (short for binary
digits).

Although you may be inclined to associate bits with numeric
values, they are only symbols whose meaning depends on the
application at hand.

The bits are used to represent information on any form on the
computer; they can be used to represent a numeric value or a
character in an alphabet or even sometimes images or sound!

Regardless of data type, bits are used to represent the data in
temporary and permanent storage.
Boolean Operations

To understand how individual bits are stored and
manipulated inside a computer system, it is convenient
to assume that 0 represents the value false, and the bit
1 represents the value true.

Operations that manipulate true/false values are called
Boolean Operations.

The fundamental Boolean operations are AND, OR and
XOR (exclusive or).
AND, OR, XOR

The Boolean operation AND, OR, XOR is designed to reflect
the truth or falseness of a statement formed by combining
two smaller, or simpler, statements.

Assuming you have two different values, P and Q;

P AND Q is true (1) only when both of its input components are
true

P OR Q is true (1) only when any or all of its input components
are true

P XOR Q is true(1) only when its input components are opposite
to one another (i.e. different).
Gates

A device that produces the output of a Boolean operation when
given the operation’s input values is called a gate.

Gates are the building blocks that show how computer systems
store and transfer bit data.

Gates are represented distinctively shaped diagrams, within the
input values entering on one side and the output existing on the
other.

Each Boolean operation is represented with a different shape on
Gate diagrams.

In today’s computer systems, gates are implemented as small
electronic circuits in which the digits 0 and 1 are represented as
voltage levels.
Gates: AND, OR, XOR,
NOT
output
x
x
y
y
output
OR
AND
x
output
y
output
x
NO
T
XOR
Inputs
Output
x
y
x AND y
x OR y
x XOR y
NOT x
0
0
0
0
0
1
0
1
0
1
1
1
1
0
0
1
1
0
1
1
1
1
0
0
Sequential Circuit

x
y
z
Sequential Circuits are formed of the combination of
gates. In a realistic circuit, two or more gates come
together to form a circuitry.
Sequential Circuit
Exercise

Given the values x=1, y = 0 and z =1; what will be the
output of the sequential circuit?
1
0
1
Sequential Exercise
Solution
1
0
1
1
0
0
The output is 0
Video Material
Evolution of Computers
Transistors