Lecture slides on:
Computer Software
Electrical/Electronics Department, School of
Engineering Tech.
Instructor:
Abdul-Rasheed O. Usman
1/14/2025
Abdul-Rasheed O.
PGD(Eng) HND(Eng)
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Intro to Computer
Software
Outline
History & Evolution of a Computer
Functional Units of a Computer
System Buses
Modem
Computer Network
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Intro to Computer
Software
• What is a Computer?
A computer is:
– An electronic machine that can be
programmed to accept data (input), process it,
stores these data and produces it into useful
information (output).
– The processing of input into output is directed
by the software, but performed by the
hardware.
– GI/GO
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Intro to Computer
Software
 Categories of a Computer
 Hardware – represents the physical and
tangible components of a computer i.e. the
components that can be seen and touched.
Examples are:
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Input devices - keyboard, mouse, etc.
Output devices – printer, monitor, speaker,
etc.
Secondary storage devices – hard drive,
CD, DVD etc.
Internal components – RAM, CPU,
motherboard etc.
Software – includes operating system and
software applications.
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Intro to Computer
Software
Relationship between Hardware and Software
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Hardware and software are mutually dependent on each
other. Both of them must work together to make a
computer produce a useful output.
Software cannot be utilized without supporting hardware.
Hardware without set of programs to operate upon cannot
be utilized and is useless.
To get a particular job done on the computer, relevant
software should be loaded into the hardware . i.e. a device
driver is needed.
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Intro to Computer
Software
• HISTORY OF COMPUTER
 Computer has come to revolutionize the word. Its
development was based on the need to solve
sophisticated calculations.
 Computer popularity surged in 1980s when Apple and
Microsoft included operating system (OS) with mixed
graphics and text which replace the old text-only
system of the 70s.
 By 90s computer incorporated enhanced
communication and multimedia applications which
has now become part of our every day lives.
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Intro to Computer
Software
•
Early Computing
• Original definition of the word computer was, ‘ a person
who made calculations’. This was between 1600s to the
20th century when it became regarded to as a ‘machine’.
 ABACUS
• The computer is based on the concept of Abacus. It was
the first computer made.
• It consists of a wooden frame with strings attached on it in
which colourful beads are strung.
• It was developed in Asia in 2700 – 3000 BC. It was a
physical counting system that allowed basic arithmetic
calculations, such as, addition and subtraction.
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Intro to Computer
Software
• PASCALINE
• It was a counting device built in 1942 by a
French mathematics and Philosopher name
Blaise Pascal to help his father. It was also
known as Pascal’s calculator. It performs both
addition/subtraction.
 It was improved upon by a German called Von
Gotlfried in 1671. He name THE STEPPED
RECKNONER, it performed addition,
subtraction, multiplication and division as
well as square roots. It uses Gears and Levels
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Intro to Computer
Software
Diagrams of Abacus and Pascaline
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Intro to Computer
Software
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JACQUARD’S LOOM
 In 1801 a Frenchman Joseph Jacquard (Weaver) built a
machine to help weave complicated patterns.
 It uses punched paper cards as templates attached to the
device on a loom which directs the movements of needle,
threads & fabrics, cresting elaborate patterns.
 The development of this machine was an important step
in computer development because the use of punched
cards formed the idea of programability.
 It emphasized three concepts;
 Information can be coded on punched cards.
 Cards could be linked to series of instructions.
 Programs could automate jobs.
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Intro to Computer
Software
• DIFFERENCE ENGINE
 Charles Babbage is regarded as the father of
computer.
 He was the first to exploit and adopt Jacquard’s
Loom idea of punch cards and developed his own
machine known as the Difference Engine in 1822.
 The machine had wheels and teeth which it used in
carrying out mathematical calculations.
 It is capable of computing several set of numbers
and making hard copies of the result.
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Intro to Computer
Software
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HOLLERITH TABULATING MACHINE
 It was an electromechanical machine designed to assist in
summarizing information stored on punched cards .
 It was developed in 1880s by Herman Hollerith to help
process data for the 1890 US Census. It is also used for
accounting and inventory control.
 At the end of the 19th century, all this ideas and technology
formed the basis for the realization of practical computer. e.g.;
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Vacuum tube
Boolean algebra
Punched cards and tapes
Teleprinter
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Intro to Computer
Software
• ABC COMPUTERS
 In 1937, a physics professor, John Atanasoff developed
the first ever electronic digital computer but the
machine wasn’t programmable.
 It was designed to reduce the time in which his physics
students used in solving complicated calculations and
solving linear equations.
 A working model of professor John’s work was finished
in 1942 which made use of electronic medium with
vacuum tubes, base numbering systems and logic
circuits.
 This paved the way for modern computer.
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Intro to Computer
Software
 ENIAC (ELECTRONIC NUMERICAL INTEGRATOR AND COMPUTER)
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It was the first general purpose electronic computer. It was used for data
manipulation, digital and able to solve large class of numerical problems
through reprograming.
It was designed by John Mauchly and Presper Eckert in 1946 for the US military
to help calculate ballistic trajectories. It uses decimal
The use of vacuum tubes was its major advantages, while, Its demerits include;
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Its programs were wired on boards
It could only store and manipulate only a limited amount of information
 EDVAC (Electronic Discrete Variable Automated Computer)
Unlike ENIAC, it uses binary instead of decimal. It was built in 1946 by Dr john Von
Noumann. He introduced the concept of storing instructions and data in memory of
a computer as binary.
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Intro to Computer
Software
GENERATION OF COMPUTER
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Generation in computer terminology is a change in technology
a computer is/was,
Before now, it was used to distinguish between the varying
types of hardware but now includes both hardware and
software which together makes up a computer system.
There are five (5) generations of computer;
 FIRST GENERATION (1946-1959)
• It uses vacuum tubes for circuitry and magnetic drums for
memory.
• These tubes are like bulbs which made them generate a lot of
heat and were prone to frequent fusing of the installations.
• It also used punched cards.
• It could only solve one problem at a time.
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Intro to Computer
Software
GENERATION OF COMPUTER
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It also employed the use of magnetic tape, input and output devices
Languages used was Wired board language.
Main Features;
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Unreliable
Very costly
Vacuum tube tech
Generate too much heat
Slow input/output devices
Non-portable
Needs AC
Consumed lots of electricity
Computers
ENIAC
EDVAC
UNIVAC
IBM-701
IBM-650
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Intro to Computer
Software
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GENERATION OF COMPUTER
SECOND GENERATION (1959-1965)
Unlike the first generation it made use of Transistors.
It used punched cards for input and printout for output.
Supports machine and assembly Languages:
FORTRAN
COBOL, etc.
 Features
 Use of transistors
 Reliable compared to FG
 Faster
 Smaller size
 Very costly
 Computers;
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IBM 1620
IBM 7094
CDC 1604
UNIVAC 1108
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Intro to Computer
Software
GENERATION OF COMPUTER
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THIRD GENERATION (1965-1971)
This generation used Integrated Circuit (IC) in place of transistors.
IC was invented by Jack Kilby and it comprises of many transistors, resistors and
capacitors along with the associated circuitry.
It makes the computer smaller in size, reliable and efficient.
Features
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IC used
More reliable
Smaller size
Faster
Less maintenance
Supports high level languages
Languages;
FORTRAN i-iv
PASCAL
COBOL
BASIC
ALGOL
 Computers;
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IBM 360
PDP (Programmed Data Processor)
IBM 370/168
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Intro to Computer
Software
GENERATION OF COMPUTER
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FOURTH GENERATION (1972-2010)
It made use of Very Large Scale Integrated (VLSI) circuits.
This also brought about the design of the processor (CPU).
Microprocessors along with the ICs helped make it possible for computers to fit easily pn the desk
and paved the way for the introduction of laptops.
They became more reliable, powerful, compact and affordable.
Languages;- C, C++, DBASE, etc.
Features
 VLSI tech
 Portable & reliable
 Very Cheap
 Use of PC
 Very small size
 No AC needed
 Became easily available, etc.
Computers;
DEC 10
IBM 5100
PDP II
CRAY-1 (Super Computer), etc.
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Intro to Computer
Software
GENERATION OF COMPUTER
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FIFTH GENERATION
Makes use of Ultra Large Scale Integrated circuits (ULSI) which results in the production of
microprocessor chips having over 10 million electronic components.
It is also the beginning of the use of Parallel Processing hardware and AI software.
AI is an emerging branch in computer science, which interprets the means and methods of making
computers think like humans.
It includes; Neural Networks, Robotics, gaming, etc
Examples of AI;Apple’s Siri
Microsoft Cortana
Google Assistant
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High level Languages;- C++, Java, Python, etc
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Features
ULSI tech
Development of AI
Advancement in Parallel Processing
More user friendly interface
Examples of this generations;
Intel P4
AMD
Athlon, etc
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Intro to Computer
Software
Fifth Generation
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Intro to Computer
Software
 What is Software?
• Software are programs and information that are loaded onto the
computer.
• Having software in a computer is like giving the computer a brain
• Without it, a computer will not be capable of processing data.
 Programs – consists of set of instructions that tells the hardware
what to do and how to behave.
• Whenever the computer wants to process data, it is the programs that tells the
CPU what to do with all the input data.
 There are two main types of software;
 Application software
 System software
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Intro to Computer
Software
 Types of Software
 Application Software – is a type of computer program that performs a specific
personal, educational and business functions.
• That is, you can type letters, do mathematical calculations create graphics
and make a movie
• Examples include:
1. Microsoft suite of products (Office, Excel, Word, PowerPoint, Outlook, etc.)
2. Internet browsers like Firefox, Mozilla, Chrome and Safari.
3. Mobile pieces of Softwares such as Pandora, (for music), Skype (for real-time
online communication), etc.
Functions of Application Software
• Manipulating data
• Managing information
• Constructing visuals
• Coordinating resources
• Calculating figures
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Intro to Computer
Software
 Types of Software Contd….
 System Software
• Is a software which directly interacts with the hardware of the system and
provides a common platform that run on top of it i.e. it is designed to provide a
platform for other software. Or,
• It is designed to run a computer’s hardware or application programs.
• It is needed to control, support and run the computer.
• Examples;
a)
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Operating system – is a low level software that supports a computer’s basic
function, such as scheduling tasks and controlling peripherals. Examples;
i.
Microsoft Windows
ii.
LINUX
iii. UNIX
iv. OS X for Apple systems
v.
Android, iOS and Windows phone (Types of Mobile devices OS)
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Intro to Computer
Software
 Types of Software Contd…
a)
b)
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Utility software – is a software designed to help analyze, configure,
optimize or maintain a computer. It is used to support the computer
infrastructure.
i.
Antivirus
ii. Backup software
iii. Compression utility etc.
Device drivers – is a computer program that operates or controls a
particular type of device that is attached to a computer. It provides a
software interface to hardware devices, enabling O.Ss and other
computer programs to access hardware functions. Examples;
i.
Monitor driver
ii. Printer driver
iii. Mouse driver. Etc.
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