Scheme of work
Week
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Topic
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1
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Writing the scheme of work/introduction
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2-3
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OVERVIEW OF COMPUTER SYSTEM
·
Definition of computer
·
Constituents of a computer
·
Computer hardware
·
Computer software
·
Characteristics of a computer
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4
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DATA AND INFORMATION
·
Definition of data and information
·
Differences between data and information
·
Examples of data and information
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5-6
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COMPUTING DEVICES 1(Pre-computer age to 19th century)
·
Features, components and uses of:
Abacus, Slide rule, Napier’s bone, Pascal’s calculator, Leibniz
multiplier, Jacquard’s loom, Charles Babbage difference and Analytical
engine, Hollerith machine `
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7-8
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COMPUTING DEVICE II (20TH century to date)
·
Features, components and uses of:
ENIAC, EDVAC, UNIVAC 1, Desktop PC, Laptop and Notebook computer,
Palmtop computer.
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TOPIC ONE: OVERVIEW OF COMPUTER SYSTEM
Definition of a Computer
A computer can be defined as an
electronic machine (device) which under the control of a stored program accepts
data, stores the data, processes the data and brings out the results as
information.
Computer as an IPOS system
Computer performs 4 key
operations on data
a. Input b.
Processing c. Output d. Storage
Input: data are
entered into the computer through the input unit. Data are raw facts that are
to be processed into meaningful form.
Processing:
Computer performs certain operations on data entered into it; the Central
Processing Unit (CPU) handles this operation.
Output: The
result of what has been processed will be displayed by the output device such
as the monitor.
Storage: Inputted
data and processed information are stored in the memory and permanent storage
on the computer.
Constituents of a Computer
system
The computer is referred to as a system because
it is made up of several components that work together to enable it function
properly. There are 2 main constituents of the computer system, these are:- The hardware
- The Software
Hardware
These are the physical components of the computer system.
They are the tangible parts that can be seen and touched. There are two major
parts, namely:
·
The system unit
·
The peripherals
System unit: The system unit is the
rectangular casing that houses (contains) several important components that
controls the operation of the computer system such as the motherboard, CPU
(Microprocessor), RAM, Sound card, video card, CD drive, Floppy disk drive etc.
It also provides interface for connection of the peripherals.
Peripherals: These are the devices connected to the system unit for
the purpose of input, output and storage operations. Examples of peripheral
devices are keyboard, Mouse, Monitor, Printer, Scanner, DVD, CD, USB flash
drive etc.
Software
The software is a term used to describe the collection (or set) of programs
that can be run on a computer system. A program is a set of instructions that
tells the computer what to do, when to do it and how to do it.
There are two types of software, these include:
- System software
- Application software
System
software: This software controls the computer hardware and the internal
operations of the computer system. Examples include Windows OS (Windows XP, Windows
ME, Windows Vista, Windows 7, Windows 8, Windows 10), Linux OS(Redhat, Fedora,
Ubuntu etc.), MAC OS etc.
Application
software: These are software that enables the user to perform specific operation
or task on the computer. Examples include:
Application software (packages)
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Functions / Uses
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MS Word, WordPad, WordPerfect
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Used for word processing
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MS Excel, Lotus1-2-3, Quattro Pro
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Used for spreadsheet, calculation and analysis
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Corel draw, Paint, Photoshop, PageMaker, Corel Graphics
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Used for graphic works
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Front page, Publisher, Dreamweaver, cold fusion
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For web designing
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MS Access, Oracle, Postgre sql, Fox pro, Dbase, Ingress, MySQL
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For database management
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MS outlook, Outlook express, MS exchange, Sendmail
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For email management
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MS PowerPoint, Impress, Prezi, Harvard Graphics
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Used for presentation of seminars and lectures
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Maths, MATLAB, SPSS, Mintab
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Create and edit mathematical formulae/statistical analysis
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Internet explorer, Mozilla firefox, chrome, Opera mini, UC browser,
Netscape Navigator, Safari , Mosaic,
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Internet/Web browsing
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Characteristics of a Computer
- · Speed: Computer performs its data processing operation at a very high speed. The speed of the computer is measured in Hertz (Hz). A computer with speed rating of Mega Hertz (MHz) can perform millions of cycle of operation per second.
- · Accuracy: Computer gives accurate result as long as the correct data is keyed into it.
- · Versatility: computer can be used to perform various kinds of task e.g. graphic design, word processing, web development etc.
- · Reliability/Durability: Computers do not get tired like human; they can work continuously for days and weeks without any error.
- · Memory and storage: Computer can store large amount of data and information. The capacity of the memory/storage device is measured in bytes. A byte is a group of eight bits. A kilobyte (KB) is 1024 bytes. A megabyte (MB) is 1,000,024 bytes.
- · Programmable: The computer hardware is useless without the program that controls it. Thus, all tasks and activities performed by a computer are made possible by means of a program.
- · It is electronic in nature
TOPIC TWO: DATA AND INFORMATION
Data
Data
are raw facts and figures without any added interpretation. Data can be defined
as a representation of facts or concepts in a formalized manner which should be
suited for interpretation or processing by human or electronic machine.
Examples of data include:
- Symbols: $, @, &, /, # etc.
- Figures/Numbers: 1, 2, 34, 0.12 2 etc.
- Alphabets: A-Z or a-z
- Words: Tunde, Facts, Ibadan etc.
Information
Information
is an organized or classified data which has some meaningful values for the
receiver. It can also be defined as the
processed data on which decisions are based. Examples of information include:
- Computer is a representation of modern life
- 2 x 7 = 14
- 10%
of
N1000 =N100
Sources of data and information
Sources of data
Data
are used for information generation and this can be obtained from different
sources. Some of the sources of data include:
- Observations
- Questionnaires
- Interviews, survey and fieldwork
- Registrations
- Experiments
- Form filling
Sources of information
Information
can come from virtually anywhere — media, blogs, personal experiences, books,
journal and magazine articles, expert opinions, encyclopedias, database,
television, newspapers and web pages — and the type of information you need
will change depending on the question you are trying to answer.
Differences between data and
information
Data
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Information
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Data
is used as input for the computer system.
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Information
is the output of data.
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Data
is unprocessed facts and figures.
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Information
is processed data.
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Data
doesn’t depend on Information
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Information
depends on data.
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Data
is not specific.
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Information
is specific.
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Data
doesn’t carry a meaning
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Information
must carry a logical meaning.
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Data
is the raw material.
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Information
is the product.
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Data
cannot be used for decision making.
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Information
is used for decision making
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Qualities of good
information
- Relevance: It must be suitable for the purpose it is required for.
- Accurate: It be free from errors
- Availability: It should be easy to obtain or access
- Timely: It should be available at the right time
- Comprehensive/Completeness: It should contain all necessary details
- Reliability: It should come from a reliable source.
TOPIC 3: COMPUTING DEVICES I
- · Abacus
Features and components
Abacus was invented around 500
BC. It was made up of strings or wires, frames and beads. Modern Abacus uses
sliding beads in columns that are divided into two by a center bar. The upper
part is called the heaven and each of the two beads (representing the two
hands) is worth 5 when moved to the center. The lower part is called the
“earth”, where each of the 5 beads (representing the 5 fingers) is worth 1 when
moved towards the center. The Abacus is really just a representation of the
human fingers.
Use
For addition and subtraction
- · Napier’s Bone
Features and components
John Napier in 1617 invented the
Napier’s bone. The device
involves a collection of moveable numbered rods and a board.
Use
Used to perform multiplication
- · Slide rule
Features and components
William Oughtred invented the slide in 1632. The Slide rule is
a mechanical analog computer. In its most basic form, the slide rule uses two
logarithmic scales to allow rapid multiplication and division of numbers.
Uses
The slide rule is used mainly
for multiplication and division, and also for "scientific" functions
such as roots, logarithms and trigonometry, but usually not for addition or subtraction.
- · Pascal’s calculator
Features and components
Blaise Pascal invented the
Pascal’s calculator otherwise called PASCALINE in 1642. It is a gear or dial driven
(just as that on analogue telephone) calculating device.
Use
It could only be used for
addition and subtraction operations. It’s use is evident in odometer and
electricity meter.
- · Leibniz multiplier
Features and components
Leibniz multiplier or (Stepped
Reckoner) was invented by Gottfried William Leibniz in 1671. It was an
improvement on the PASCALINE. It contains a special kind of gear called “Leibniz
wheel”.
Uses
It could add, subtract, multiply
and divide.
- · Jacquard’s loom
Features and components
In 1801, Joseph Marie Jacquard
invented the Jacquard’s loom. This machine was controlled by a number of
punched cards, put together into a continuous sequence.
Use
Used for producing fabrics with beautiful
patterns
- · Difference engine
Features and components
In 1822, An English mathematics
professor called Charles Babbage invented the Difference engine. It was
composed of 25000 parts, weighed 15 tons and stood 8 feet (2.4m) high.
Use
Used for calculating
differential equations.
- · Analytical engine
Features and components
In 1832, Charles Babbage
designed another machine called Analytical engine which was deemed to be the
first mechanical computer. The machine was steam-powered, though never
completed, outlined the basic elements of a modern day general purpose
computer. It contains input in the form of punched card containing operating
instructions and a "store" for memory of 1,000 numbers of up to 50
decimal digits long. It also contained a "mill" with a control unit
that allowed processing instructions in any sequence, and output devices to
produce printed results. Augusta Ada, Countess of Lovelace (1815-1842) created
the instruction routines to be fed into the computer, making her the first
female computer programmer.
Use
It could store 1000 numbers of
up to 50 decimal digits long. It was programmable.
- · Herman Hollerith machine
Features and components
Herman Hollerith invented the Herman
Hollerith machine which used punch card to store information which he fed into
the machine to compile the results mechanically.
Use
It was used for collating,
sorting and summing the data gotten from 1980 US census.
TOPIC FOUR: COMPUTING DEVICES II
- · ENIAC
In 1946, John Mauchly and J. Presper Eckert completed the ENIAC
(Electronic Numerical integrator and Calculator). It was the first general
purpose computer. ENIAC contained 18,000 vacuum tubes, weighed 30 tons,
occupied 1800 square feet of floor space and required 160 kilowatts of electrical
power. The ENIAC used punched card for input and output. ENIAC was used by US
for hydrogen bomb project and programming.
- · EDVAC
Features
and components
The EDVAC (Electronic Discrete Variable Automatic Computer) is the successor of the
ENIAC and was made by the same designers: John Mauchly and Presper Eckert in 1949.
Unlike its predecessor the ENIAC, it was binary rather than decimal. It was the first
designed stored program computer with memory capacity of 1000 words (later set to
1,024 words, thus giving a memory, in modern terms, of 5.5 kilobytes). It contains
6,000 vacuum tubes and consumed 56 KW of power and covered 490 square feet of
floor space.
UNIVAC 1
Features and components
The UNIVAC 1 (Universal Automatic Computer 1) was invented by John Mauchly and
Presper Eckert in 1951. The machine was 25 feet by 50 feet in length, contained
5,600 tubes, 18,000 crystal diodes, and 300 relays and had an internal storage capacity
1,000 words or 12,000 characters. It utilized a Mercury delay line, magnetic tape, and
typewriter output. Magnetic tape was still used for input and output. It was the
first commercial computer.
Assignment
State the features and components of the following devices
· Desktop Personal Computers
· Laptop and Notebook Computers
· Palmtop computers
TOPIC 5: INPUT DEVICESThese are the hardware devices that are used for entering data and instructions into the computer system. The input devices allow human to interact with the computer system. The followingare some examples of Input devices:Keyboard: Most important input device. The keyboard is very much like a typewriter keyboardwith a few additional keys. The keys when pressed send an input signal into the computer.Mouse: A mouse is a small object you can roll along a hard or flat surface. It controls the movementof the cursor on a display screen.Light pen: An input device that utilizes a light-sensitive detector to select, create and modify objecton a display screen.Touchpad: A touchpad is used for pointing on a computer display screen. It works by sensing theuser’s finger movement and downward pressure. It is often rectangular in shape and found mostlyon laptops. It is an alternative to mouse.Touch screen: It allows the user to operate / make selections by simply touching the display screen.The display screen is sensitive to touch of a finger or stylus. Widely used on ATM machines andmost mobile phones.Microphone: A device that is used to capture and record sound.Bar code reader: These are photoelectric scanners that read bar codes printed on product containers.They are generally used in super markets.Scanner: Scanner reads texts, images or illustrations printed on paper and translate the informationinto a form that the computer can use. It works by digitizing an image.Magnetic Ink Character Recognition (MICR): MICR can identify character printed with a specialink that contains particles of magnetic material. This device is widely used in banking industry.Optical Mark Recognition (OMR): Also called mark sense reader is a technology where an OMRdevice senses the presence or absence of a mark, such as pencil mark. OMR is widely used in tests such as aptitude test.Joystick: Is an input and pointing device used in computer games.Digital camera: An input device used to capture images and moving pictures.Differences between Mouse and KeyboardAssignment
