I. Basic Computer Concepts
1.1: Information Technology Fundamentals
Learning Objectives
At the end of the session, the students should be able to:
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Define basic concepts on computer as such computer, data and information.
Relate the development of computing and computing devices.
Describe the development of computing devices, their capabilities and limitations.
Explain the different components of computer systems.
Describe the role of each component in the functionality of the computer.
Describe basic troubleshooting techniques and proper use of hardware and software.
Presentation of Contents
What is a Computer?
By modern definition, a computer is an electronic device that accepts (inputs),
processes, stores, and outputs data at a high speeds according to programmed instructions. If
you look closely at the definition, you can see that a computer is made up of five basic
elements:
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Electronic – means all computers are powered by electricity.
Programmable – computers follow set of instructions (called programs) in order to
operate.
Storage – computers are able to store huge amount of data for future use (electronic
cabinet).
Retrieve – computers are able to get back or return whatever it has stored.
Process – computers are able to transform or manipulate data it has stored into useful
information.
Data and Information
Data is raw, unprocessed facts. It has the potential to become useful information, but
first it has to be manipulated and transformed. And the best way to do that is to feed the data
into the computer. Data is actually what computers feed on. Meanwhile, information is
processed data. It is a data that has already manipulated and transformed into something
useful.
Four Basic Functions of Computer
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All computers perform the following four basic functions:
Input – the procedure of feeding or entering data into a computer.
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Process – the operation of manipulating and transforming data into something useful.
This function is done through programs. Programs are written instructions that tell
the computer on how to manipulate and transform the data it was given to it.
Output – the result of the processing function.
Storage – computers save data and outputs for later use.
Capabilities and Limitations of a Computer
A computer is a machine that needs to be controlled and instructed to successfully
perform a task. No matter how powerful and sophisticated it is, it must be directed what to
do. Users should follow the principal of GIGO (Garbage In, Garbage Out) which means
that wrong data entered into the computer will result to wrong information produced.
Capabilities of a Computer
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It can process data quickly.
It can perform operations tirelessly.
It can give accurate results depending on the instructions and commands given.
It can store, recall, and retrieve information.
It can confirm and verify the accuracy of the information.
It can perform multi-tasks.
Limitations of a Computer
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It needs human intervention.
It has a short life span.
It cannot formulate information on its own.
The information or results generated are user dependent.
It can never replace the capabilities of the human brain.
History of Computer
INVENTION
Abacus
INVENTION
Logarithms
Pascaline
ANCIENT TIME
DESCRIPTION
The abacus was man’s first recorded adding machine. It was in 500
B.C when the abacus was invented in Babylonia, then popularized in
China, the abacus is an ancient computing device constructed of
sliding beads on small wooden rods, strung on a wooden frame.
MECHANICAL ERA
DESCRIPTION
John Napier, Baron of Merchiston, Scotland, invents
logs in 1614. Logs allow multiplication and division
to be reduced to addition and subtraction.
In 1642, a French mathematician named Blaise Pascal
invented a mechanical calculation machine called
Pascaline. It was made out of clock gears and levers,
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Stepped Reckoner
Jacquard Loom
Difference Engine
Analytical Engine
Ada
INVENTION
Punched card
Tabulating
machine
Millionaire
INVENTION
Z3
and could solve basic mathematical problems like
addition and subtraction.
In 1671, Gottfried Leibniz, a German mathematician,
invented a machine called steeped reckoner that could
multiply 5 digit and 12 digit numbers yielding up to
16 digit number.
In 1801, Joseph-Marie Jacquard developed an
automatic loom that was controlled by punched cards.
In 1822, Charles Babbage, invented the first modern
computer design: a steamed-powered adding machine
called the difference engine to automatically solve
math problems.
Babbage also invented the analytical engine. It was a
mechanical adding machine that took information
from punched cards to solve and print complex
mathematical operations.
Babbage’s difference and analytical engine are
regarded as the first “thinking machines”. These
inventions earned him the title “Father of Computers”
The first program was written by Ada Augusta
Lovelace for Babbage’s difference engine. Thus, Ada
Lovelace is credited with being “the first computer
programmer”. The programming ada is named in her
honor.
ELECTROMECHANICAL ERA
DESCRIPTION
In 1890, the first person to successfully use punched cards specifically
for census taking was Herman Hollerith. The punched card was
adapted for use in early computers and provided computer
programmers with a new way to put information into their machines.
Hollerith later went on to found the Tabulating Machine Company,
which later became the Computer Tabulating Recording Company. He
retired in 1921, but his
company went on to become the
International Business Machines Corporation. We know it today as
IBM.
The Millionaire, the first efficient four-function calculator, is invented
by Otto Shweiger, a Swiss Engineer in 1893.
ELECTRONIC ERA
DESCRIPTION
In 1941, Konrad Zuse, built the first programmable computer called
Z3. It was the first fully functional, program controlled computer of
the world. The Z3 was presented on May 12, 1941 to an audience of
scientist in Berlin. The demonstration was a success.
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Mark I
ABC(AtanasoffBerry Computer)
Howard Aiken, a Ph.D. student at Harvard University built Mark I
“The first Stored-Program Computer”. 8 feet tall, 51 feet long, 2 feet
thick, weighed 5 tons, used 750,000 parts, 500 miles of wires, 3-5
seconds per calculation.
In 1942, John Atanasoff and Clifford Berry completed the first allelectronic computer called ABC (Atanasoff-Berry Computer). It was
the first computer to use electricity in the form of vacuum tubes. It
was used for solving complex systems equations.
The Five Generations of Digital Computing
The First-Generation Computers (1951-1958)
 First-generation computers had vacuum tubes, resistors, and welded metal joints.
They were large, slow, expensive, and produced a lot of heat. In addition, firstgeneration computers often broke down because of burned-out vacuum tubes.
 In 1945, Presper Eckert and John Mauchly developed the first operational electronic
digital computer, called ENIAC, for the US Army. ENIAC had more than 18,000
vacuum tubes, and took up to 1,800 square feet of space. Today, ENIAC’s technology
could fit in a modern wristwatch.
 In 1951, the UNIVAC-1 became the first commercially available electronic computer.
This computer was designed by Eckert and Mauchly and built by the Remington Rand
Corporation.
 IBM 701 was the IBM’s first electronic computer built in 1953.
The Second Generation Computers (1959-1963)
 Instead of vacuum tubes, the second-generation computers used transistors an exciting
new invention at the time. John Barden, Walter Brattain, and William Shockley of
Bell Telephone Laboratories invented the transistor.
 Magnetic tapes and disk began to replace punched cards as external storage devices.
 Magnetic cores (very small donut-shaped magnets that could be popularized in one of
two directions to represent data) strung on wire within the computer became the
primary internal storage technology.
 In 1961, Grace Hopper, the woman that found the first computer bug, finishes
developing COBOL (Common Business-Oriented Language).
 The Digital Equipment Corporation (DEC) founded by Ken Olsen, released the first
minicomputer, the PDP-8 in 1964.
 In 1965, Thomas Kurtz and john Kemeny of Dartmouth College developed BASIC
(Beginners All Purpose Symbolic Instruction Code) as a computer language to help
teach people how to program.
The Third-Generation Computers (1963-1974)
 Computers in the third-generation computers relied on a new technology called
integrated circuit. The integrated circuit is a single wafer or chip that can hold many
transistors and electronic circuits.
 Magnetic tape and disks completely replace punched cards as external storage
devices.
 Magnetic core internal memories began to give way to a new form, metal oxide semiconductor (MOS) memory, which, like integrated circuits, used silicon-backed chips.
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1. According to Size and Processing speed:
a. SUPERCOMPUTERS
- The fastest type of computer.
- very expensive and employed for specialized applications that require immense amounts of
mathematical calculations.
- They are mainly for:
> weather forecasting
> animated graphics
> fluid dynamic calculations
> nuclear energy research
> petroleum exploration
 Examples:
> NEC Earth Stimulator
> IBM ASCI White
> TERASCALE Computing System
> TERA Supercomputer
> NERSC IBM SP RS/600
b. MAINFRAME COMPUTERS
- very large and expensive computer capable of supporting hundreds, or even thousands of
users simultaneously.
- slower and less than supercomputers.
- support hundreds or thousands of users at a time.
- used as e-commerce and web servers and in large organizations, banks, universities and
airlines as databases.
- server
 Examples:
> IBM 3090
> Andhal 5890
c. MINICOMPUTERS
- midsized computer
- size and power, lies between workstations and mainframes.
- multi-processing system capable of supporting from 4 to about 200 users simultaneously.
- known as midrange computers.
- used in medium sized business, education and government departments and are also used as
servers on the network environment.
 Examples:
> IBM'S AS/400e
d. MICROCOMPUTERS (Personal Computers)
- generally a synonym for the more common term, PC, computer designed for an individual.
- user microprocessor technology to input, manipulate, store and output data.
- Business use personal computers for word processing, accounting, desktop publishing and
for running spreadsheet and database management applications.
 Examples:
> Apple 2 (1977)
> IBM PC
TWO CLASSIFICATIONS OF MICROCOMPUTERS
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1. Personal Computer or PC
- laptop or notebooks, sub-notebook, tablet computer and personal digital assistants.
- small enough to move easily from one place to another and they can operate on batteries.
- popular with people who travel and need computing power on the go.
> Laptop / Notebook Computer
- a small portable computer. Can sit on your lap
- use a variety of techniques, flat-panel technologies, to produce a lightweight and non-bulky
display c. screen.
> Subnotebook Computer
- slightly lighter and smaller than a full-sized notebook computer.
- smaller keyboard and screen, equivalent to notebook computers.
> PDA or Personal Digital Assistant
- Handheld device that combines computing, telephone / fax, and networking features.
- cellular phone, fax sender and personal organizer.
- began as pen-based, using stylus rather than a keyboard.
> Tablet PC
- provide full power and functionality for today's notebook PC's.
- Design for a fully equipped personal computer that allows a user to take notes using a
natural handwriting on a stylus or digital pen.
2. According to Data Handled:
a. Analog computers
- operate on mathematical variables in the form of physical quantities that are continuously
varying. Ex: temperature, pressure, voltages etc.
- Planimeter, nomogram, operational amplifiers, mechanical integrators..
b. Digital Computers
- deal with mathematical variables in form of numbers that represent discrete values of
physical quantities.
- versatile, reprogrammable, accurate, less affected by outside disturbances.
- work on numbers, binary
- all modern computers, laptops, calculators
c. Hybrid Computers
- combination of digital and analog. Combines best features of both types.
- speed of analog computer and memory and accuracy of digital.
- used mainly in specialized applications where both kinds of data need to be processed.
> Computer used in hospitals to measure the heartbeat of patient. Petrol pump. In scientific
applications or in controlling industrial processes.
3. According to Purpose
a. General- purpose Computers
- capable of dealing to a variety of different problems and are able to respond to programs
created to meet different needs.
- capable of storing different programs of different instructions this they can perform a
variety of operations.
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- Ex: Desktop Computer
b. Special Purpose Computers (Dedicated Computers)
- destined to perform one specific task.
- built into permanently in the machine and given task are performed very quick and efficient.
- Ex: computers used in monitoring nuclear reactions, outer space missions, oil explorations
COMPONENTS OF A COMPUTER SYSTEM
1. HARDWARE
- physical equipment associated with a computer system. Tangible components of a computer
system.
Four Primary Components of a Computer Hardware System
a. INPUT DEVICES - any hardware that allows the user to enter data, execute
commands and user responses into the computer.
- Data entry
> Keyboard - typewriter keys that enables you to enter data.
> Mouse - Douglas Engelbert of Stanford. Device that controls the movement of the cursor.
> Joystick - hand held stick that pivots about one end and transmits its angle. Often used in
control games
> Light Pen - a small, photosensitive device connected to a computer and oved by hand over
an output display in order to manipulate info into computer.
- used in personal digital assistant and smart board.
> Microphone - receive and record sound. Voice recognition software
> Digital Camera - takes pictures without film and stores your snapshots as digital files in its
memory.
> Barcode Reader - optical scanning device that reads texts which have been converted into a
special bar code or zebra stripes.
> Webcam - digital camera capable of capturing images
> Drawing Tablet - similar to a white board, except you use a special pen to write on it.
> Scanner - takes in an optical image and digitalized it into an electric image.
 Four Kinds of Scanner:
> Flatbed Scanner - flat, glass surface to hold pages of paper.
> Sheet-fed Scanner - allows only paper to be scanned rather than books or thick objects.
Stationary scan head
> Handheld Scanner - moved across the image to be scanned by hand. Small and less
expensive than their desktop counterparts.
> Drum Scanner - used to capture the highest resolution from an image. Photographs and
transparencies are taped, clamped or fitted into a clear cylinder.
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b. OUTPUT DEVICES - presents, displays, alters or record output after it has left a
computer's system unit.
> Monitor - most popular output device. Receives signal from video card and gives the user a
graphical or textual display. Cathode Ray Tube
> Speakers - used to produce sounds, listen to music, play music and watch movies.
> Printer - create images on paper, plastic, cloth and other print media using technologies like
ink transfer.
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Types of Printer
> Laser Printer - uses toner and an internal laser to print.
> Inkjet or Bubble Jet Printers - uses ink to print. Usually available in color.
> Dot-Matrix Printer - creates characters by striking pins against an ink ribbon. Each pin
makes a dot.
c. STORAGE DEVICES - these are important for keeping a document for later
retrieval and use.
TWO CLASSIFICATIONS OF STORAGE DEVICES:
1. Primary Storage - the main memory.
> ROM ( Read Only Memory ) - permanent memory.
> RAM ( Random Access Memory) - temporary memory. Memory loss when switched off.
2. Secondary Storage - external memory
EXAMPLES OF EXTERNAL SECONDARY STORAGE DEVICES
a. Hard Disk - magnetic disk
b. CD-ROM - optical disk format used to hold texts, graphics and sounds that are prerecorded.
- small, flat metal-coasted plastic disc
c. Flash Drives - type of compact USB memory drive that acts like a portable hard drive.
d. SYSTEM UNIT - part of computer which accepting and processing the data brought
in by the input devices, passing resulting information to the users via the output
devices.
COMPONENTS OF SYSTEM UNIT:
> Main Circuit Board - central nervous system. Motherboard
> Port - from the main circuit board to a peripheral device such as keyboard, printer or a
video monitor by means of a special cable. Called Interface.
> Expansion Slots - they are used to connect expansion cards to the main circuit board.
> Central Processing Unit (CPU) - computer's processing, control and internal storage
circuitry.
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Bytes - unit of measurement in measuring memory
Hertz - measuring speed
Bit - binary digits. Basic unit of data recognized by computer.
1 Bite = 8 bits
1 Kilobytes = 1024 bytes
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1 Megabytes = one million bytes
1 Gigabytes = one billion bytes
1 Terabytes = one trillion bytes
11. SOFTWARE - the program and data that a computer uses.
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Kinds of Software
1. Application Software - what people use to get their work done.
Ex:
> Word Processor - used for the production of any sort of printable material.
- MS-Word MS-Publisher Page Maker
> Spreadsheet Software - business data in a grid of rows and columns.
- MS-Excel
> Graphics and Presentation - used to display information. Form of slideshow.
- MS-PowerPoint
> Database Software - helps a user organize data in a way that allows fast and easy access to
the data.
- MS-Access Oracle MySQL
> Games - involves interaction with a user interface to generate visual feedback on a video
device.
- Mario, Solitaire, FreeCell
> Internet Browser - enables a user to display and interact with text, images, and other
information typically located on a Web page.
- Internet Explorer, Google Chrome
2. SYSTEM SOFTWARE - includes all programs used to operate and maintain the
computer system. It controls all input output functions.
- most important software sabi ni maam alar lolz
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Operating System - set of computer programs that manage the hardware and software
resources of a computer.
- DOS, WINDOWS, LINUX, MAC
 Programming Languages - used to write or create other programs or software.
- FORTRAN, COBOL
3. UTILITY SOFTWARE - known as the service program, service routine, tool.
- specially designed to help manage and tune the computer, hardware, operating system or
application software, and perform a single task small range.
- Disk Defragments, System Profilers, Virus Scanners
4. PEOPLEWARE - the users of the computer. The system analysts, programmers, web
developer, students who in a way works with the computer.
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