2. The mouse is one of the most common
input devices used.
The mouse usually has two buttons, a right
and left one and also wheel which allows
you to scroll up and down the page.
The mouse cursor is shaped like an arrow or
a hand.
It enables you to control what happens on
screen and you can point, select, drag and
click items.
3.
4. Ideal for use with desktop computers.
Most computer users are familiar with them
and require little training.
Works well in conjunction with keyboard for
data entry.
5. It is not easy and convenient to input text
using a mouse.
It is not accurate enough to use for
drawings that require high precision.
They need a flat space close to the
computer.
Overuse can lead to RSI (Repetitive
Strain Injury).
8. This pointing device is specially
designed to all the disability people.
9. A trackball is a input pointing device
that consist a ball held on top and contains
sensors to detect a rotation of the ball
about two axes.
The user rolls the ball with
the thumb, fingers, or the palm of
the hand to move a pointer.
11. From type writers, key boards were formed. A
keyboard is an input device as it is plugged
into the computer by a wire. The teletype
machine which was invented in the 1930’s
was combined with a telegraph.
Early computer keyboards were adapted in the
year 1046 by a punch card and teletype
technology.
12. A keyboard is one of the most needed devices
of a computer. Without a keyboard, words
cannot be punched into the computer,
therefore no data will be found.
Keyboards come in different shapes and sizes,
some incredibly big and some rather small.
A new system of typing now, is by using touch
screen devices such as ipads and smart
phones.
14. In computing, a keyboard is a typewriter-style
device, which uses an arrangement of buttons or
keys, to act as mechanical levers or electronic
switches. Following the decline of punch cards and
paper tape, interaction via teleprinter-style
keyboards became the main input device for
computers.
15. A keyboard typically has characters engraved or printed on
the keys and each press of a key typically corresponds to a
single written symbol. However, to produce some symbols
requires pressing and holding several keys simultaneously
or in sequence. While most keyboard keys produce
letters, numbers or signs (characters), other keys or
simultaneous key presses can produce actions or computer
commands.
Despite the development of alternative input devices, such
as the mouse, touchscreen, pen devices, character
recognition and voice recognition, the keyboard remains
the most commonly used and most versatile device used
for direct (human) input into computers.
16. In normal usage, the keyboard is used to type text and
numbers into a word processor, text editor or other
programs. In a modern computer, the interpretation of key
presses is generally left to the software. A computer
keyboard distinguishes each physical key from every other
and reports all key presses to the controlling software.
Keyboards are also used for computer gaming, either with
regular keyboards or by using keyboards with special
gaming features, which can expedite frequently used
keystroke combinations. A keyboard is also used to give
commands to the operating system of a computer, such as
Windows' Control-Alt-Delete combination, which brings
up a task window or shuts down the machine. Keyboards
are the only way to enter commands on a command-line
interface.
21. Rom (Read only Memory)
What is ROM?
Is memory that is capable of holding data
and having that data read from the chip.
21
22. The disadvantages of ROM
It is only economical to buy mask ROM in
large quantities, since users must contract
with a foundry to produce a custom design.
The turnaround time between completing
the design for a mask ROM and receiving
the finished product is long, for the same
reason.
22
25. Read-only memory (ROM) is a class of storage medium used in
computers and other electronic devices. Data stored in ROM cannot be
modified, or can be modified only slowly or with difficulty, so it is mainly
used to distribute software that is very closely tied to specific hardware,
and unlikely to need frequent updates.
Other types of non-volatile memory such as erasable programmable
read only memory and electrically erasable programmable read-only
memory or Flash ROM are sometimes referred to, in an abbreviated way,
as "read-only memory" (ROM); although these types of memory can be
erased and re-programmed multiple times, writing to this memory takes
longer and may require different procedures than reading the
memory. When used in this less precise way, "ROM" indicates a non-
volatile memory which serves functions typically provided by mask ROM,
such as storage of program code and non volatile data.
27. THE MEANING OF OUTPUT IN GENERAL
Output it the term denoting either an exit or
changes which exit a system and which activate/
modify a process. It is an an abstract concept, used
in the modelling, system(s) design and
system(s) exploitation.
28. PRINTER AS AN OUTPUT DEVICE
In publishing, printers are
both companies providing printing services and
individuals who directly operate printing presses.
The profession of printer became established after
the invention of the moveable type printing
press by Johannes Gutenberg around 1450, and
proliferated throughout Europe. Such early printers
often were recognizable by individual
characteristics in the works they produced, such as
type or typography, and since early printed books
were made in relatively small quantities they are
rare and collectible.
31. What is a sound card?
A sound card is an internal computer component that processes audio files in
order to provide high-quality playback through computer speakers. A sound
card plays voice as well as music files, and can handle various audio file formats
including .wav, .Mp3and .cda to name but a few. The typical sound card has an
interface available at the back of the computer with various input and output
ports. The quality of the sound card and speakers both affect the overall sound
quality of the computer system. Speakers plug directly into the back of the
sound card.
A sound card also has a line-in port for listening to or recording from an
external device such as a digital audio player. If the source device does not have
a line-out port to connect to the sound card, a stereo cable can be run from the
headphone jack on the source device to the line-in port on the sound card.
Software configurations may be required to hear the device playing.
Another port on a sound card is the microphone port. By plugging in an
external mic, one can record notes, lectures, daily personal logs, audio blogs
or podcasts. For private listening, every sound card features a headphone
jack, which offers the perfect way to enjoy MP3s, DVDs or other audio files
without disturbing others.
32. How does a sound card work?
Sound cards have a standard operation for controlling sound on computers--of
processing the input and output of sound. The input comes from other devices such as
microphones or MIDI musical instruments. The sound card takes the sound from the
device, records it and then processes it. For output, the device takes instructions from the
program and plays the sound through speakers connected to the computer.
34. Speakers
Speakers are very common today.
Many computers/laptops have them built in.
Many people use them to listen to music on their
smartphones,tablets,laptops and/or computer.
They are external to a computer.
38. › A video card is an expansion card which
generates a feed of output images to a
display.
› A video card can also be called:
• A video adapter,
• A display card,
• A graphics card,
• A display adapter,
or
• A graphics adapter.
39. Most video cards offer various functions
such as:
• Accelerated rendering of 3D scenes and 2D
graphics,
• MPEG-2/MPEG-4 decoding,
• TV output,
or
• The ability to connect multiple monitors
(multi-monitor).
40. Video hardware can be integrated into
the motherboard or the CPU, but all
modern motherboards provide
expansion ports to which a video card
can be attached.
In this configuration it is sometimes
referred to as a video controller or
graphics controller
42. Why is your screen an output device?
• A screen is an output device because it displays
what you are doing.
• We don’t give commands to the computer by
using the screen.
44. Why are Projectors used?
A Projector is a device designed to take an image from a
video source and project it onto a screen or other surface.
The projector reflects the video signal off of thousands of
tiny mirrors inside the projector itself, allowing for
improved clarity and resolution when the image is projected
onto a screen.
Projectors are used in a variety of different ways due to their
ability to project movies and television programs onto a
screen much larger than even the biggest TV available.
46. - An input device is any hardware device that sends
data to the computer, without any input devices, a
computer would only be a display device and not
allow users to interact with it, much like a TV.
- Output devices are pieces of computer hardware
that allow a computer system to communicate
information to a user or another system. This
information can be in any form, and includes
sound and images.
Rebecca Parnis, 4.3
49. •Modems are both input and output devices as the
internet transmission is passing from the
company E.g. Go Internet; through the modem, to
us users with internet access.
Rebecca Parnis, 4.3
51. Information about the Graphic
Tablet
The graphic tablet is a input device
It enables a user and draw pictures
and graphics
It can be used to trace an image from
a piece of paper
52. More Information!
The device consists of a flat surface
which the user may draw or trace
It is displayed on a computer monitor
53. Uses of the Graphic Tablet
They are considered to offer a way to
create graphic designs
In East Asia they are used in
conjunction with writing Chinese,
Japanese and Korean characters
56. What is voice recognition?
Voice recognition is the computer analysis of a
human voice.
It is very useful for people who are blind and
cannot type on the keyboard.
It helps them because they don’t have to
struggle by trying to type the correct letters on
the keyboard.
It may also be used to give commands to the
computer.
57. Advantages of voice recognition
Over 100 built-in Speech is a natural
commands way to interact –
Easy to use even with computers
New commands can Helps people who
be easily added have trouble using
Application their hands
downloads are Helps people with
usually free disabilities
No training is
required for the
users
58. Computer Accessibility
Computer accessibility refers to the accessibility
of a computer system to all people, regardless of
disability or severity of impairment.
There are numerous types of impairment that impact computer use. These include:
•Cognitive impairments and learning disabilities.
•Visual impairment.
•Hearing impairment.
•Motor or dexterity impairment.
Is vision loss to such a degree as to qualify as an
additional support need through a
significant limitation of visual capability.
Carla Vella Form 4.3
59. Visual impairment: application that attempts to
A screen reader is a software
identify and interpret what is being displayed on the screen
(or, more accurately, sent to standard output, whether a video
monitor is present or not).
Mild to medium vision impairment, it is helpful to use large fonts,
high DPI displays, high-contrast themes and icons supplemented with
auditory feedback and screen magnifying software.
Severe vision impairment (blindness), screen reader software that
provides feedback via text to speech or a refreshable braille display is
a necessary accommodation for interaction with a computer.
A text-to-speech (TTS) system converts normal language text
Colour-blindness, colour shouldn’t berender symbolic distinguishing
into speech; other systems the only way of linguistic
between different pieces of information. However, the only colour
representations like phonetic transcriptions into speech.
combinations that matter are those that people with a deficiency
might confuse, which generally means red and green and blue and
green.
60. Technology for the Visually Impaired
• Using speech with the computer
Speech synthesis are used read text and screen contents giving visually
impaired and blind users access. Those with very severe difficulties may
require specialised speech screen reading software.
• Specialised equipment for the visually impaired
In addition to standard computer equipment there is a range of special
electronic equipment designed to be used by people with a visual
impairment. This includes purpose made portable Braille computers and
Braille input and output devices for standard computers.
• Getting the environment right
An appropriate working environment is important for people with visual
impairments. Good glare free lighting will be required for
reading, while the
screen will
need to be away from
direct light.