What is a computer?
□ A computer is an electronic device that
manipulates information, or "data." It has the
ability to accept, store, retrieve, and process
data.
Examples of computer includes:
INFORMATION
PROCESSING CYCLE
Components of the Information Processing
Cycle
INPUT PROCESS OUTPUT
STORAGE
Components of the Information
Processing Cycle cont’d
□ Input—involves entering data or instructions
into the computer memory.
□ Processing—involves performing operations
on the data or instructions.
□ Output—involves presenting the results.
□ Storage—involves saving data, programs, or
output for future use.
INPUT DEVICES
Input Device
This is a hardware component of the
computer that is used to enter data or
instructions into the memory of the
computer.
Categories of Input Devices
Key entry
This is the use of keys to enter data into the computer.
Categories of Input Devices
Terminal entry
A terminal is comprised of a keyboard, monitor and a video card.
Data is entered or inputted into the computer by the use of keys.
Categories of Input Devices
Point and draw entry
Allows the user to control a pointer on the screen.
Categories of Input Devices
Multimedia entry
Used to enter video, graphics and audio into the computer.
Categories of Input Devices
Source data entry
Data is captured from a source document into the computer.
Key Entry Input Devices
Keyboard
This is an input device that is made up
of keys which are used to enter data or
instructions into the computer.
Point and draw input devices
Mouse
This is a handheld device that is used to click
on icons or objects which are located on the
computer screen. There are two types namely,
optical and mechanical.
Point and draw input devices cont’d
Trackball
The trackball is a device that has a similar design
to the mouse. It has a ball located at its top and
is used to move objects on the computer screen
or make selections. The trackball is ideally used in
areas where there is limited desk space.
Point and draw input devices cont’d
Light Pen
This is a hand held device that possesses the ability to
detect light. The user is allowed to select objects on the
screen by pressing the tip of the pen on the screen or
pointing on the object and pressing a button on the pen.
Point and draw input devices cont’d
Touch Screen
A touch screen is a touch sensitive display device.
The user interacts with it by touching areas on the
screen with the finger. It does not require the
user
to enter a lot of information. Normally the user is
just required to touch words, pictures or numbers
identified on the screen.
Point and draw input devices cont’d
Joystick
This is a device which is comprised of a
vertical lever that is fixed to a base. It is used
to move objects on a computer screen. The
joystick is used to play computer games.
Point and draw input devices cont’d
Graphic Tablet or Drawing Tablet
The graphic tablet is a pressure-sensitive data
input device that responds to a user’s movement
of a pen, mouse, or other device to select an image.
Point and draw input devices cont’d
Touch Pad
This is a device that is pressure and direction
sensitive. The user is required to move or tap their
finger on the surface to move objects or make
selections.
Point and draw input devices cont’d
Remote Control
This is an electronic device that is
used for the
remote operation of a machine.
They are used to issue
commands from a distance.
Remotes communicate with
infrared (IR) and radio signals.
Multimedia Entry Input Devices
Digital camera
A digital camera is a device that allows users
to take pictures and store the photographed
images digitally instead of on a film. Images
can be transferred from the camera to the
computer hard disk.
Multimedia Entry Input Devices
PC Camera/ PC video camera/Web Camera
This is a type of digital video camera which
allows the user to capture video and still images.
It is connected directly to the computer by a
USB port or firewire port.
Multimedia Entry Input Devices
Microphone
The microphone is a device
that is used to enter
speech or sound into the
computer.
Multimedia Entry Input Devices
Voice Response Unit/VRU
This is a computer telephony integration (CTI)
term that refers to the communication between
a human (typically a caller) and a computer
that is programmed to respond to the human's
requests. It can also be referred to as an
IVR (interactive voice response) which is an
automated telephone response system that
presents a series of choices to the caller, accepts
a selection/input from the caller and provide the
appropriate response.
Source data entry input devices
Optical Scanner/Scanner
A scanner is a light sensing input device that
reads printed text and graphics and translates
the results into a form that can be processed
by the computer.
Source data entry input devices
Optical Character Reader
This is a device that uses light to read
characters, marks and codes and then
converts them into digital data that the
computer can process.
Source data entry input devices
Bar code scanner/reader
This is an optical reader that uses laser beams to read
bar codes. A bar code is an identification code that is
comprised of vertical lines of different widths and
numbers. A bar code is unique to a product.
Source data entry input devices
MICR (Magnetic Ink character Reader)
The MICR is a device used to read characters that are
written using magnetic ink. The MICR characters are
converted in a manner so that the computer can be
able to process it. These characters are found on
cheques.
Source data entry input devices
OMR (Optical Mark Reader)
The OMR is a device that is used to read
marks that are made on a special form in
certain places. These marks can either be
circles or rectangles.
Source data entry input devices
Sensor
This is a device that is used to produce and
send electronic signals to the computer. It is
also a device that measures a physical
quantity and converts it into a signal which
can be read by an observer or by an
instrument.
Source data entry input devices
Biometric system
Biometrics is a field of science that uses computer
technology to identify people based on physical or
behavioural characteristics, such as fingerprints or
voice scans.
The biometric system is a pattern recognition system
which recognizes a user by determining the
authenticity of a specific physical or behavioural
characteristic possessed by the user. A biometric
system can be used for either verification or
identification.
Terminal Entry Input Devices
POS (point of sale) Terminal
A POS is the physical location at which goods are sold to
customers. A point-of-sale (POS) terminal is a computer
replacement for a cash register. It is more sophisticated than
the traditional cash registers and it normally includes the
ability to track customer orders, process credit cards, and
manage inventory.
Assignment:
□ State two places where MICR can be used.
□ List two benefits of scanning a document
instead of typing it.
□ List two ways in which sensors can be utilized
in the real world.
□ Explain one way in which supermarkets that
use barcode readers can benefit.
