COMPUTER
BASICS
MRS. SUSIWALA
Basic Understanding of
Computers
MICROPROCESSORS -- THE BRAIN OF THE
COMPUTER
PCs primarily use microprocessors
(sometimes called the chip).
The CPU (Central Processing Unit) is normally an
Intel Pentium (or equivalent) and it is one of the
most important components within your
computer.
COMPUTER SYSTEMS
WHAT IS A
COMPUTER?
❑ An electronic device that stores,
accesses, and processes data,
and can be programmed with
instructions.
❑ A computer
is made up of
hardware and software, and
can exist in many different
sizes and set-ups.
TYPES OF COMPUTERS
Mini mainframe and Supercomputers
• Very powerful, used by large organizations such
an banks to control the entire business
operation. Very expensive!
Personal Computers
• Cheap and easy to use. Often used as standalone computers or in a network. May be
connected to large mainframe computers within
big companies.
THE FOUR FUNCTIONS OF A COMPUTER
Function
What Does It Do?
Input
Accepts data
Processing
Processes data
Output
Produces output
Storage
Stores results
Computer Hardware Functions
Input Devices
Memory
RAM
ROM
Central
Processing
Unit
Output Devices
Secondary
Storage
Devices
General Understanding of how Computers Work
Input
Processing
The computer
collects information
or instructions
from you.
You can provide the
computer with input
from devices such
as a keyboard, a
mouse, a stylus,
webcam, or by
speaking into a
microphone.
The computer
interprets and
processes the data
you have inputted.
It adds, multiplies,
divides, finds, or
manipulate data or
text to complete a
task you have given
it.
Output
The computer produces
information that has
been processed.
The output might be
something you see on
the screen (such as an
answer to a
mathematical problem),
something you hear
(such as that “ding”
when you have made an
error), or something
you ask the computer
to print.
Storage
The computer saves-stores-information or instructions in
it’s memory
Peripheral
Devices
HARDWARE & SOFTWARE
Hardware refers to the physical
components of your computer.
• Examples include mouse, keyboard, monitor etc.
The software is the instructions that
makes the computer work. (You can not
touch)
Examples include Systems software and
Application software.
SOFTWARE
• Software - set of electronic instructions
that tell a computer what to do.
• Example:
• System software
• Operating system software
• Application software
• Microsoft
• Word, Excel, PowerPoint,
• Publisher and Access
• Google
• Docs, Sheets, Slides, Sites,
Application Software - Google Chrome
Sites
INPUT AND OUTPUT DEVICES
Input Devices – Tells the computer what to do .
Things you use to put information into the computer
Examples of input devices are:
• A keyboard
• mouse
• joysticks
Output Devices -- “how the computer shows you what it's done” Everything you use to get
information out.
Examples of output devices are:
• The monitor (the screen) is how the computer sends information back to you.
A printer is also an output device.
INPUT DEVICES
▪ The Mouse
• Used to ‘drive’ Microsoft
Windows
▪ The Keyboard
• The keyboard is still the
commonest way of entering
information into a computer
▪ Tracker Balls
• an alternative to the
traditional mouse and often
used by graphic designers
INPUT DEVICES
•
Scanners
A scanner allows you to scan printed
material and
convert it into a file format that may be
used within the PC
•
Touch Pads
A device that lays on the desktop and
responds to pressure
•
Light Pens
Used to allow users to point to areas on a
screen
•
Joysticks
Many games require a joystick for the
proper playing of the game
OUTPUT DEVICES
OUTPUT DEVICES
•
Monitor
• The
computer screen is used for
outputting information in an
understandable format
•
Printers
• There
are many different types of
printers.
• In large organizations laser
printers are most used due to
the fact that they can print very
fast and give a very high-quality
output.
OUTPUT DEVICES
OUTPUT DEVICES
• Speakers
• Enhances the value of
educational and
presentation products.
• Webcams
•
Headphones
MEMORY
Storage Devices – How the computer
saves data and programs:
✔ Hard disk drives are an internal,
higher capacity drive which also
stores the operating system which
runs when you power on the
computer.
✔ USB allow you to save work take the
data with you.
MEMORY
RAM
RANDOM ACCESS
MEMORY
RAM - Random Access Memory
The main 'working' memory
used by the computer.
ROM – Read Only Memory
as the name suggests is a
special type of memory chip
that holds software that can be
read but not written to.
V
ROM
READ ONLY MEMORY
STORES INFORMATION
FOR A SHORT TIME
STORES INFORMATION
PERMANENTLY
DATA CAN BE CHANGED
INFORMATION INSIDE
CAN NOT BE CHANGED
DATA IS LOST WHEN THE DATA IS SAFE WHEN PC
PC IS TURNED OFF
IS SWITCHED OFF
VERY FAST –BUY USES A FAST – BUT USES VERY
LOT OF POWER
LITTLE POWER.
NOT
PERMANENT
PERMANENT
How Computer Memory Is Measured
❑Bit
All computers work on a binary numbering system, i.e.
they process data in one's or zeros. This 1 or 0 level of
storage is called a bit.
❑ Byte
A byte consists of eight bits.
❑ Kilobyte
A kilobyte (KB) consists of 1024 bytes.
❑ Megabyte
A megabyte (MB) consists of 1024 kilobytes.
❑ Gigabyte
A gigabyte (GB) consists of 1024 megabytes.