1. Lesson 2B: INPUTTING DATA IN OTHER WAYS
Objectives:
» List two reasons why some people prefer alternative
methods of input over a standard keyboard or mouse.
» List three categories of alternative input devices.
» List two types of optical input devices and describe their
uses.
» Describe the uses for speech-recognition systems.
» Identify two types of video input devices and their uses
2. Overview: Options for Every Need and Preference
Although the keyboard and the mouse are the input devices that people use most often, there
are many other ways to input data into a computer. Sometimes the tool is simply a matter of
choice. Some users just prefer the feel of a trackball over a mouse. In many cases, however, an
ordinary input device may not be the best choice. In a dusty factory or warehouse, for example,
a standard keyboard or mouse can be damaged if it becomes clogged with dirt. Grocery
checkout lines would slow down dramatically if cashiers had to manually input product codes
and prices. In these environments, specialized input devices tolerate extreme conditions and
reduce the risk of input errors. Alternative input devices are important parts of some special
purpose computers. Tapping a handheld computer's screen with a pen is a much faster way to
input commands than typing on a miniature keyboard. On the other hand, a specialized device
can give new purpose to a standard system. If you want to play action-packed games on your
home PC, for example, you will have more fun if you use a joystick or game controller than a
standard keyboard or mouse.
This lesson examines several categories of alternative input devices and discusses the
special uses of each. You may be surprised at how often you see these devices, and you may
decide that an alternative device will be your primary means of interacting with your computer.
3. DEVICES FOR THE HAND Most input devices are designed to be used by
hand. Even specialized devices like touch screens enable the user to
interact with the system by using his or her fingertips. Unlike keyboards
and mice, many of these input devices are highly intuitive and easy to use
without special skills or training.
» Pens Pen-based systems—including many tablet PCs, personal digital
assistants, and other types of handheld computers—use a pen for data
input. This device is sometimes called a stylus. You hold the pen in your
hand and write on a special pad or directly on the screen. You also can use
the pen as a pointing device, like a mouse, to select commands by tapping
the screen. Pen-based computers are commonly used for data collection,
where the touch of a pen might place a check in a box to indicate a part
that must be ordered or a service that has been requested. Another
common use is for inputting signatures or messages that are stored and
transmitted as a graphic image, such as a fax. When delivery service drivers
make deliveries, they often have recipients sign their names on such a
computer-based pad. As handwriting recognition technology becomes
increasingly reliable, pen-based systems will undoubtedly become more
common.
4. » Touch Screens
Touch screens accept input by allowing the user to place
a fingertip directly on the computer screen, usually to
make a selection from a menu of choices. Most
touchscreen computers use sensors on the screen’s
surface to detect the touch of a finger, but other
touchscreen technologies are in use, as well. Touch
screens work well in environments where dirt or
weather would render keyboards and pointing devices
useless, and where a simple, intuitive interface is
important. They are well-suited for simple applications,
such as automated teller machines or public
information kiosks. Touch screens have become
common in fast-food restaurants, department stores,
drugstores, and supermarkets, where they are used for
all kinds of purposes, from creating personalized
greeting cards to selling lottery tickets.
5. » Game Controllers
A game controller can be considered an input device because a computer
game is a program, much like a word processor. A game accepts input
from the user; processes data, and produces output in the form of
graphics and sound. As computer games become more detailed and
elaborate, more specialized game controllers are being developed to take
advantage of their features. Game controllers generally fall into two
broad categories: gamepads and joysticks.
1. Joysticks.
Joysticks enable the user to “fly” or “drive” through a game, directing a
vehicle or character. They are popular in racing and flying games. A
variant of the joystick is the racing game controller, which includes an
actual steering wheel; some racing game controllers even include foot
pedals and gearshifts.
2. Game pads.
A gamepad is a small, flat device that usually provides two sets of
controls—one for each hand. These devices are extremely flexible and
are used to control many kinds of games. If you do not have a joystick,
you can use a game pad to control most racing and flying games.
JOYSTICK
GAME PAD
6. »Optical Character Recognition (OCR)
If you have scanned a text document,
you might want to use optical character
recognition (OCR) software to translate
the image into text that you can edit.
When a scanner first creates an image
from a page, the image is stored in the
computer’s memory as a bitmap. A
bitmap is a grid of dots, each dot
represented by one or more bits. The job
of OCR software is to translate that array
of dots into text that the computer can
interpret as letters and numbers.
7. » Image Scanners
The bar code reader is a special type of image scanner.
Image scanners (also called scanners) convert any printed
image into electronic form by shining light onto the
image and sensing the intensity of the light’s reflection at
every point. The image scanner is useful because it
translates printed images into an electronic format that
can be stored in a computer’s memory. Scanners come in
a range of sizes from handheld models to flatbed
scanners that sit on a desktop.
1. Handheld scanners are more portable but typically
require multiple passes to scan a single page because
they are not as wide as Ietter-size paper.
2. Flatbed scanners offer higher-quality reproduction
than do handheld scanners and can scan a page in a
single pass. To use a flatbed scanner, you place the
printed image on a piece of glass similar to the way you
place a page on a photocopier.
8. Audio visual Input Devices
Today, many new PCs are equipped with
complete multimedia capabilities. New
computers have features that enable them
to record audio and video input and play it
back.
» Microphones
Now that sound capabilities are standard in
computers, microphones are becoming
increasingly important as input devices to
record speech. Spoken input is used often in
multimedia, especially when the
presentation can benefit from the narration.
Most PCs now have phone dialing
capabilities.
9. Microphones also make the PC useful for audio and videoconferencing over the
Internet. For this type of sound input, you need a microphone and a sound card. A sound
card is a special device inside the computer; which translates analog audio signals (that is,
sound waves) from the microphone into digital codes the computer can store and
process. This process is called digitizing. Sound cards also can translate digital sounds
back into analog signals that can then be sent to the speakers.
There is also a demand for translating spoken words into text, much as there is a
demand for translating handwriting into text. Translating voice to text is a capability
known as speech recognition (or voice recognition). With it, you can dictate to the
computer instead of typing, and you can control the computer with simple commands,
such as Open or Cancel.
Speech-recognition software takes the smallest individual sounds in a language,
called phonemes, and translates them into text or commands. Although the English
language uses only about 40 phonemes, reliable translation is difficult. For example, some
words in English have the same sound but have different meanings (two versus too, for
example). The challenge for speech-recognition software is to deduce a sound’s meaning
correctly from its context and to distinguish meaningful sounds from background noise.
10. Other Types of Audio Input
If your sound card has a built-in Musical
Instrument Digital Interface (MIDI) port,
or if you have a dedicated MIDI adapter,
you can connect many kinds of electronic
musical instruments to your computer
MIDI based instruments can communicate
with and control one another, and any PC
can be used to control MIDI instruments
and to record their output. MIDI is
extremely popular among musicians of all
stripes, who use it to write, record, and
edit music, and even to control
instruments and effects during
performances.
11. » Webcam
A popular and inexpensive type of
PC video camera—called a
Webcam—can sit on top of a PC
monitor or be placed on a stand, so
the user can “capture” images of
himself or herself while working at
the computer. This arrangement is
handy for videoconferencing,
where multiple users see and talk
to one another in real time over a
network or Internet connection.
12. » Digital Cameras
Digital cameras work much like PC
video cameras, except that digital
cameras are portable, handheld
devices that capture still images.
Whereas normal film cameras
capture images on a specially
coated film, digital cameras capture
images electronically. The digital
camera digitizes the image,
compresses it, and stores it on a
special memory card.
13. SUMMARY
» With a pen-based system, you use a pen (also called a stylus) to write on a special pad or directly on the
screen.
» Pen-based computers are handy for writing notes or selecting options from menus, but they are not well-
suited for inputting long text documents.
» Touch-screen systems accept input directly through the monitor. Touch-screen systems are useful for
selecting options from menus, but they are not useful for Inputting text or other types of data in large
quantities.
» A game controller is a special input device that accepts the user's input for playing a game. The two
primary types of game controllers are joysticks and game pads.
» Bar code readers, such as those used in grocery stores, can read bar codes, translate them into numbers,
and input the numbers into a computer system.
» Image scanners convert printed images into digitized formats that can be stored and manipulated in
computers.
» Microphones can accept auditory input. Using speech-recognition software, you can use your
microphone as an input device for dictating text navigating programs, and choosing commands.
» To use a microphone or other audio devices for input, you must install a sound card on your computer.
» A sound card takes analog sound signals and digitizes them. A sound card also can convert digital sound
signals to analog form.
» PC video cameras and digital cameras can digitize full-motion and still images, which can be stored and
edited on the PC or transmitted over a LAN or the Internet.
14. Test I. FILL IN THE BLANK. Complete each statement by writing the term in each
blank. (10 points)
1. The pen used with a computer—such as a tablet PC—is also called a ______?
2. You might not think of a_______ as a true input device, but it is.
3. You can find______ being used as input devices in supermarkets and department
stores everywhere. 4. A bar code reader is a special type of______.
5. In a computer, a_______ translates analog audio signals into digital codes the
computer can use.
6. The process of translating voice into text or commands the computer can
understand is called_______.
7. Using a special_______ camera, you can participate in online videoconferences.
8. A___________ is a popular and inexpensive type of PC video camera.
9. Using a ________ you can connect video devices such as a VCR or camcorder to
your PC
10. A________ stores still images on a special memory card, rather than on film.
