This is a CPU (central processing unit) which is like the brains of the computer.
It is the element that carries out the functions of the computer. This component
communicates to the other components about the speed of the processing. Speed
of processing is the clock speed that it has which can be different on each CPU
and can be increased. The CPU function is the input which is the keyboard, the
process which is the computer program being executed and the output is what
you can see on the monitor.
This RAM (Random access memory) which makes your computer run. The
more memory you have the faster the computer will run. Also it will help
with the amount of applications that are running. This component
communicates with other components for data storage. Its function is a
temporary storage for data when the program is opened it is stored in the
RAM. It will be much faster from looking through the hard drive with all of
those Gbs to look through.
This is a power supply to all components that are on the motherboard. There
are a number of different pin connectors that can connect to the motherboard
depending on what type of motherboard you have. This component
communicates to other components by supplying power to each component so
they can run.
This is a motherboard which holds all the components together. It allows
components to receive power and communicate with each other. This is the
main unit where all components are connected and can communicate with
each other component.
This is a graphics card and this is needed so you have something to look at on
your monitor. Everything is passed through the graphics card and outputted
through the monitor. The graphics card passes through the visuals that are
being processed. The graphics card communicates with the motherboard to see
what needs to be visualised onto he motherboard. If you use on board graphics
it can take some of the RAM memory away. The graphics card has a VGA port
or HDMI and the VGA cable will connect from the card to the monitor.
This is a heat sink which sits on top of the processor to coo down the processor
so the processing can run smoothly. The processor will communicate with the
heat sink to tell it when it needs cooling down.
This is a wireless network card so you can connect to the internet for your
computer. This component communicates with the wireless feed from your
router to connect to the internet. The network card has an Ethernet port slot for
the cable to go in and then go to the router or switch. The network is put into a
PCI slot on the motherboard and powered from.
This is a hard drive for storage of all your documents and operating system.
This component communicates with the motherboard so that information is
processed and saved to the output hard drive. The hard drive has a magnetic
head which reads through all the disks on the hard drive and reads the data in
binary code (01010101). The hard drive is connected to the motherboard with
either SATA or IDE and also power from the power supply.
This is an optical drive which runs all CD ROMs. This component
communicates with the CD ROM and communicates to the graphics card to see
the end product form the CD that is inside the optical drive. The optical drive is
also connect through either SATA or IDE which is connected to the
The bios is another chip that is on the motherboard which is a piece of software that
has all the settings of the computer. It has all the in depth information on the CPU like
the clock speed and the MB in cache it has. The bios will allow you to overclock your
CPU if needed to make your computer perform faster. It allows you to change any
settings that you wish to change. The bios is stored in the ROM which is the read only
memory where the data in the memory can not be modified like the bios which is a
program that boots the computer in the ROM which is read only.
Software & Hardware?
• Computer Instructions or data, anything that can be stored
electronically is Software.
Hardware is one that is tangible. The storage devices (Hard
disk, CD’s etc.,), mouse, keyboard CPU and display devices
(Monitor) are Hardware.
For example: There is a problem in the Software implies –
Problem with program or data
Types of Software
Open source Software and
System Software includes the Operating System and all the
utilities that enable the computer to function.
System software is a term referring to any computer software
which manages and controls the hardware so that application
software can perform a task.
Operating Systems, Compiler, Loader, Linker, Interpreter.
Application Software includes programs that do real work for
Payroll systems, Inventory Control, Manage student
database, Word Processor, Spreadsheet and Database
Management System etc.,
Open Source Software:
Open source software (OSS) is computer software whose
source code is available under a license that permits users to
use, change, and improve the software, and to redistribute it
in modified or unmodified form.
It is often developed in a public, collaborative manner.
Well-known OSS products are Linux, Netscape, Apache, etc.,
• Proprietary software (also called non-free software) is
software with restrictions on using, copying and modifying
as enforced by the proprietor. Restrictions on
use, modification and copying is achieved by either legal
or technical means and sometimes both.
• Proponents of proprietary software are Microsoft.
• Ex: CAD, Nortan Antivirus etc.,
• Operating System is a software, which makes a computer to
• It is the software the enables all the programs we use.
• The OS organizes and controls the hardware.
• OS acts as an interface between the application programs and
the machine hardware.
• Examples: Windows, Linux, Unix and Mac OS, etc.,
System Software (contd):
Compiler: A compiler is a program that reads a program
in one language – the source language and translates into
an equivalent program in another language – the target
System Software (contd):
Loader: A loader is the part of an operating system that is
responsible for loading programs into memory, preparing
them for execution and then executing them.
The loader is usually a part of the operating system's kernel
and usually is loaded at system boot time and stays in
memory until the system is rebooted, shut down, or powered
In Unix, the loader is the handler for the system call execve().
System Software (contd):
Linker: A linker or link editor is a program that takes one or
more objects generated by compilers and assembles them
into a single executable program.
Linkers can take objects from a collection called a library. The
objects are program modules containing machine code and
information for the linker.
The linker takes care of arranging the objects in a program's
System Software (contd):
Interpreter: An interpreter is a computer program
that translates and executes instructions written in a
computer programming language line-by-line, unit by
An interpreter needs to be able to analyze, or parse,
instructions written in the source language.
Example: Lisp systems, etc.,
Word processing is a tool that helps user in
creating, editing, and printing documents. Word processors
will normally have the following capabilities built into them:
» Spell checking
» Standard layouts for normal documents
» Have some characters appear in bold
print, italics, or underlined
» Center lines, make text line up on the left side of
the paper, or the right side of the paper
» Save the document so it can be used again
» print the document.
Examples: WordPerfect and Microsoft Word
The spreadsheet packages are designed to
use numbers and formulas to do calculations with
ease. Examples of spreadsheets include:
» Grade Calculations
» Address Lists
The most commonly used spreadsheet programs are Microsoft
Excel and Lotus 123.
The presentation programs
can make giving presentations and using overheads
easier. Other uses include:
» Slide Shows
» Repeating Computer Presentations on a
» Using Sound and animation in slide shows
The most recognized graphic presentation programs are
Microsoft PowerPoint and Harvard Graphics.
Database Management System (DBMS):
• A DBMS is a software tool that allows multiple users to
store, access, and process data into useful information.
• Database programs are designed for these types of
» Membership lists
» Student lists
» Grade reports
» Instructor schedules
All of these have to be maintained so you can find what you
need quickly and accurately.
• Example:Microsoft Access, dBASE, Oracle.
• Series of instructions to a computer to
accomplish a task
• Instructions must be written in a way the
computer can understand
• Programming languages are used to write
What is programming?
• Once the code (language) of a program has
been written, it must be executed
• You may need to type the name of the
program to start it, or use a word like RUN and
the name of the program (in the old
What is programming?
• Some programming languages (like Java or
C++) require the code to be compiled
(translated to binary) before it can be started.
interpreted, meaning that each command is
translated separately when the program is
What is a programming language?
• Set of commands that a computer has been
“taught” to understand
• Languages that look like “machine code” (e.g., 82A8: jsr
r5,@#82AE 82AC: sob r0,8296) are used for…
– Writing games
– Writing application programs (like Excel)
• Other languages look like English (“high level,” e.g.,
– And many more
What does programming
• Here are some examples of an instruction to print
the word HI
MESSAGE1 DC ‘HI’
How do you write a program?
• Decide what steps are needed to complete the task
• Write the steps in pseudocode (written in English) or
as a flowchart (graphic symbols)
• Translate into the programming language
• Try out the program and “debug” it (fix if necessary)
What is pseudocode?
• List of steps written in English
• Like the instructions for a recipe
• Must be in the right sequence
– Imagine saying “bake the cake” and then “mix it
• Task: add two numbers
– Get two numbers
– Add them
– Print the answer
What does a flowchart look like?
• The pseudocode from the previous slide
would look like this as a flowchart:
Get 2 numbers
What are those funny symbols?
• An IF statement always has a condition to
check, often a comparison between a variable
and a number.
• The IF statement also must specify what to do
if the condition/comparison is true.
• These instructions (for “true”) may come after
the word THEN, or they may simply be listed.
• In an IF THEN statement, when the condition
is false, the program simply ignores the THEN
commands and continues to the next line.
• In an IF THEN ELSE statement, commands are
given for both the true and false conditions.
• In most programming languages, small subprograms are used to perform some of the tasks.
• These may be called
functions, subroutines, handlers, or other such
• Functions often have names (e.g., getName or
• A function generally gets information from the
main program, performs some task, and returns
information back to the program.
• Functions follow the same rules of syntax, etc. as
the main program.