Senior 3
Computer Studies
Ms Jennifer
Senior three Computer Studies
Term 1
The term computer refers to an electronic device which is capable of
receiving information (data) in a particular form and of performing a
sequence of operations in accordance with a predetermined but variable
set of procedural instructions (program) to produce a result in the form of
information or signals. The four basic functions of a computer are:
1.
2.
3.
4.
Input – the computer receives information.
Processing – the computer processes data by executing it.
Output – the computer outputs data or information after processing.
Storage – Store data or information in the computer for later use.
The computer is made up of two main parts: Hardware and Software.
Hardware refers to all the physical components of the computer. Software
refers to all non-tangible components of a computer. Software is made up of
digital data / information.
Some examples of computer hardware terms include: Mouse, keyboard,
printer, monitor, hard drive and disk drive, modem.
Some examples of software basic computer software terms include:
application, web browser, click, file, folder, internet, GUI, icon, memory, CPU,
RAM, ROM, menu, network, peripheral, driver (digital), drag, double click, bit,
byte, megabyte, gigabyte, FAQ, windows, virus, spreadsheet, database, tool
bar, scroll bar, URL, window, internet protocol (IP) address.
1
Senior 3
Computer Studies
Ms Jennifer
The CPU - Central Processing Unit is the main processor of the computer. The
CPU job is to retrieve instructions, decodes them and executes them.
These instructions come from the operating system and from the user input
devices such as mouse clicks, opening and closing of documents, etc. Every
instruction is processed and executed by the CPU.
Therefore the CPU speed is very important in dealing with computer
instructions.
The main memory serves to store temporary data to help the CPU with the
execution of instructions. How do you think the main memory (RAM) helps the
CPU to process instructions faster? The main memory helps the CPU by storing
information and data. For example, if you use click the mouse frequently, this
instruction is stored in the main memory for faster access by the CPU. The two
main units (parts) of the CPU are the CU – Control Unit and the ALU –
Arithmetic Logic Unit which make up the processor. Other registers serve to
store data during the processing of instructions by the CPU.
INPUT
PROCESSING
OUTPUT
2
Senior 3
Computer Studies
Ms Jennifer
ASCII
ASCII stands for American Standard Code for Information Interchange.
Computers understand instructions in terms of 1’s and 0’s. However it would
be very hard for us to convert each word of our language to 1,s and 0’s.
For this reason a system was developed to cater for such a problem. The
system developed for this purpose is called ASCII by which we can use our
own alphabetic characters, both lower and upper cases, numbers and
symbols.
In order to understand how the computer interprets our language we need
to gain the knowledge required to learn the ASCII code.
There are 128 standard ASCII codes, each of which can be represented by a
7 digit binary number from 000000 through to 111111.
The letter 'A' is represented by the code: 01000001
The letter 'B' is represented by the code: 01000010
The name Jennifer in ASCII is: 074 101 110 110 105 102 101 114
The name Jennifer in binary is:
00110000 00110111 00110100 00110001 00110000 00110001 00110001 00110001
00110000 00110001 00110001 00110000 00110001 00110000 00110101 00110001
00110000 00110010 00110001 00110000 00110001 00110001 00110001 00110100
As shown in the above binary digit code, one single word is very long.
Information and Communication Technology (ICT)
I.C.T. represents all the computer hardware and digital software or data,
used to retrieve and send information to and from a computer network and
communicate with the rest of the world!
Common words that are frequently used in I.C.T. include:
Data
Information
Program
Statement
3
Senior 3
Computer Studies
Ms Jennifer
Information technology (I.T.) represents every technology (hardware and
software) that is used to deliver or retrieve information / data.
Computer Types
Supercomputers – these are very costly ranging from 182,000 euros to
millions. One supercomputer can have multiple users working on it at
the same time. These computers are used for special purposes, such as
movie productions, aircraft designs, and weather forecast and oil
explorations.
Mainframes – Similar to supercomputers (multi-user)but they are less
costly (cheaper in price) because their performance is not as good as
supercomputers, however they are very suitable for certain companies
who require the handling of millions of transactions, besides the fact
that their maintenance is much cheaper than a network of general
purpose computers.
Minicomputers – similar base system (multi-user) but only 500 users can
work on it at the same time.
Workstations – These are terminals that are used for special purposes.
Workstations have single user base system.
Microcomputers – Also called the PC (personal computer) these have
a single user base system and are built for the general public and for
everyday general purposes such as document and software
development, communication through network, editing of documents
and pictures, etc. There are various forms of PC including laptops,
desktops, notebooks, palmtops and pen computers.
Microcontrollers – These are very small special purpose computers.
These specialized small computers are pre-programmed for a specific
task. Some examples in the kitchen include special computer to cool
the fridge, special computer (mini-controller) to heat the microwave,
etc. Other examples include a mini-controller to control the fuel
consumption of a car, or a mini-controller to open and close electric
windows, etc.
4
Senior 3
Computer Studies
Ms Jennifer
Unit of storage
Advantages and Disadvantages in IT
Advantages:
Reach audience from various geographic locations
Special purpose software to help the disabled with learning and
information.
Help students, teachers, parents, and other professional with planning
schedules and freedom to work from home.
Classes from home
Learn new skills from the internet or software technology.
Decrease the need for paper (help the environment)
Disadvantages
Critically evaluate content
Incompatible technologies
Malware patches with online software
Digital challenges (problems) when submitting assignments.
Lack of motivation
Cheating on quizzes and tests.
5
Senior 3
Computer Studies
Ms Jennifer
Ergonomics
Ergonomics is the scientific discipline of the physical relationship between
people and their work environment.
Ergonomics in ICT focuses on the user’s posture while sitting and working at
their desk, sufficient adequate light, ergonomic keyboards and any other
equipment that may be necessary in order for the user to work efficiently and
productively.
Posture: Ideally the posture must be straight with the person’s back resting on
the chair’s back, the computer must be almost but not exactly at eye level
(slightly downwards) and the hands shall be at the same level of the
computer table. Users can use foot stool so they can rest their feet.
Ergonomic keyboard and mouse: these are designed to protect from RSI
(Repetitive strain Injury) on the wrist and hands.
Robots
Robots are machine systems that have been created to aid humans in their
everyday life and in scientific discoveries and experiments. Robots can be of
different shapes and sizes (not necessarily human shape). Robots can aid a
carpenter by specific sight sensors to avoid injuries. Robots are used also for
productivity because robots do not get tired like humans. Robots can be
used as gas detectors to avoid hazardous situations and protect humans.
Robots can also aid by facilitating housework or other areas such as medical
interpretations.
Disadvantages of Robots:
Expensive
Unemployment of people
Require special maintenance
Cashless Society
The term cashless society is developed by the fact of increasingly using
credits cards for purchases or any other online digital facilities such as
payment transfers.
6
Senior 3
Computer Studies
Ms Jennifer
The effect of Internet in Society
The Internet has facilitated various processes such as purchasing,
communication, access to information and learning, but it has also brought
with it incorrect, unreliable information, unappropriated communication and
digital crime and software malware.
The term EDI stands for Electronic Data Interchange which refers to any
transaction performed digitally such as online payments, online purchases.
The term EFT stands for Electronic Fingerprint Transaction which usually is used
for the identification of persons prior to entry into specific location.
The term EDP stands for Electronic data processes which refer to all electronic
processes that take place.
Crime detection and prevention with Information Technology
Some IT crime detection technologies include: CCTV’s and GPS, but what
about prevention? How can we prevent crime with technology? Perhaps the
same technologies could fear off possible crimes from happening, but is that
always the case?
Simulations
Imagine a scenario in which you would like to present a real life operation or
process and you do not have the tools or equipment to show it ‘life’. How
would you present such information to unexperienced clueless individuals?
Simulations are imitations of real life operations or processes presented in
digital form. The most common type are video representations or animations
which properly define and describe a particular process, an operation or a
situation.
7