03a - Input Devices - Inputs
-
Upload
prakashdev99 -
Category
Documents
-
view
223 -
download
0
Transcript of 03a - Input Devices - Inputs
-
7/22/2019 03a - Input Devices - Inputs
1/91
GCSE ICT
Input and Output Devices - Inputs
-
7/22/2019 03a - Input Devices - Inputs
2/91
Input devices
Input devices are used to get data into a
system.
They should be able to do this as
accurately and quickly as possible, and
with the minimum of human intervention.
-
7/22/2019 03a - Input Devices - Inputs
3/91
Input devices
The most common types of input devices
are:
Keyboards
Point and Click devices (including mouse,
tracker balls, touch sensitive pads, joysticks,
light pens, touch screens, and graphic tablets)
-
7/22/2019 03a - Input Devices - Inputs
4/91
Input devices
The most common types of input devices
are:
Readers (including magnetic strip readers,
barcode readers, optical character
readers/recognition, magnetic ink character
readers/recognition, and optical mark
readers/recognition) Punched cards and tape (including punched
cards and Kimball tags)
-
7/22/2019 03a - Input Devices - Inputs
5/91
Input devices
The most common types of input devices
are:
Sound capture devices (including voice
recognition and microphones)
Terminals (including EPOS and EFTPOS
terminals)
-
7/22/2019 03a - Input Devices - Inputs
6/91
Input devices
The most common types of input devices
are:
Digital imaging devices (including video
digitisers, scanners, digital cameras, and web
cams)
Tonal devices (including touch tone
telephones)
-
7/22/2019 03a - Input Devices - Inputs
7/91
Input Devices
keyboards,
numeric keypads,
pointing devices (including mouse, touchpad and tracker ball),
remote controls,
joysticks, touch screens,
graphics tablet,
-
7/22/2019 03a - Input Devices - Inputs
8/91
magnetic stripe readers,
chip readers,
PIN pads, digital cameras,
video cameras,
web cams, scanners,
microphones,
-
7/22/2019 03a - Input Devices - Inputs
9/91
sensors,
MICR,
OMR, OCR,
barcode readers,
light pens;
-
7/22/2019 03a - Input Devices - Inputs
10/91
Keyboards
The most common type of keyboard is
the QWERTY keyboard (so called
because the top line of letters are q, w, e,
r, t, and y.
-
7/22/2019 03a - Input Devices - Inputs
11/91
-
7/22/2019 03a - Input Devices - Inputs
12/91
Concept Keyboard
A concept keyboard is a flat
board that contains a grid of
buttons. Each button can be
programmed to do whatever
you want.
An overlay sheet with
pictures or symbols is placed
on the grid so that the user
can tell what pressing on
different areas will do.
-
7/22/2019 03a - Input Devices - Inputs
13/91
Concept keyboards are used
when fast input is needed and
are ideally suited to selecting
from a limited range of choices
such as fast food restaurants.Checkout tills such as
McDonalds use symbols to
make ordering faster and
easier. Primary schools often
use them with young children.
The overlay image could be apicture of a farmyard. Pressing
on an animal would cause the
computer to make the right
animal noise.
Concept keyboards are
particularly useful for
people who would find
using an ordinary
keyboard difficult. It isalso very handy in
locations where an
ordinary keyboard might
be damaged e.g. byspillage or dust.
-
7/22/2019 03a - Input Devices - Inputs
14/91
AdvantagesMuch faster for making non-
text selections such as menu
choices on the till of a fast-food
outlet.
The keyboard is waterproof
which can be useful where
there is dirt or the risk of
splashes
Disadvantages Poor for text or numeric
input - although some
keyboards do include a
numeric keypad so the
operator can enter the
amount sold.
Limited to the options
shown on the keyboard
-
7/22/2019 03a - Input Devices - Inputs
15/91
Keyboards
Another type of keyboard is the concept
keyboard.
The can be specially designed so that
people with restricted vision can use them
to interface with a computer.
Concept keyboards can also be
programmed to perform common functions
with one keystroke (e.g. a computerised till
in a fast food restaurant).
-
7/22/2019 03a - Input Devices - Inputs
16/91
-
7/22/2019 03a - Input Devices - Inputs
17/91
-
7/22/2019 03a - Input Devices - Inputs
18/91
Ergonomic KeyboardErgonomic computerkeyboards encourage the user
to adopt an ergonomic typing
posture which minimizes the
exposure to awkward postures
and repetitive stress. The main
concerns are the horizontal
and vertical bending of thewrists, known as ulnar
deviation and pronation
respectively. These deviations
result in the compression of
the nerves in the wrist, causing
disorders such as carpeltunnel syndrome.
carpel tunnel syndrome.
http://www.ergonomics-info.com/carpal-tunnel-ergonomics.htmlhttp://www.ergonomics-info.com/carpal-tunnel-ergonomics.html -
7/22/2019 03a - Input Devices - Inputs
19/91
-
7/22/2019 03a - Input Devices - Inputs
20/91
-
7/22/2019 03a - Input Devices - Inputs
21/91
Pin PadNumeric KeypadA small keyboard that only
has numbers.
Used to enter numeric data into
computers such as those in ATMs.
Most computer keyboards have a
numeric keypad on the right side,
and most mobile phones (there
are also computers) have a one
for entering phone numbers, etc.
This is a device with
a numeric keypad used to
enter a personsPersonal
Identity Number (PIN) e.g.
when paying with a credit
card.
PIN pads are also found on
electronic door locksyou
enter a PIN to unlock the door.
-
7/22/2019 03a - Input Devices - Inputs
22/91
-
7/22/2019 03a - Input Devices - Inputs
23/91
-
7/22/2019 03a - Input Devices - Inputs
24/91
-
7/22/2019 03a - Input Devices - Inputs
25/91
Point and Click devices
Point and Click devices include mouse,
tracker balls, touch sensitive pads,
joysticks, light pens, touch screens, and
graphic tablets.
-
7/22/2019 03a - Input Devices - Inputs
26/91
Mouse
The mouse translates movement
on the desktop into digital
information.
This information is converted intomovement of the cursor on the
screen.
A mouse will also have one, two, or
three buttons which can be clicked
to help the user to select what
functions they wish to use.
-
7/22/2019 03a - Input Devices - Inputs
27/91
The mouse is a very important input device. It helps
you to do many things, such as:
controlling the cursor or pointer
opening up menus
selecting items from menus by clicking the mousebutton
opening up software by clicking the mouse button
dragging icons to move them into folders, to save
files.
-
7/22/2019 03a - Input Devices - Inputs
28/91
Advantages Ideal for use with desktop
computers
Usually supplied as part
of a new computer
system Most computer users are
familiar with them and
require little training
Works well in conjunctionwith a keyboard for data
entry
Disadvantages They need a flat space
close to the computer
The rollers in mice that
use balls can become
clogged with grease and
grime and lose their
accuracy until cleaned.
Overuse can lead to RSI
-
7/22/2019 03a - Input Devices - Inputs
29/91
Tracker ball
The tracker ball is essentially an
upside down mouse.
Instead of moving the mouse on
the table top, the ball is rotated. This achieves the same result as
using a mouse but takes up far
less room.
-
7/22/2019 03a - Input Devices - Inputs
30/91
Used as an alternative to a
mouse. To operate it theuser rotates the ball whichmoves the pointer onscreen. They areparticularly easy to use forthose with limitedmovement in their handsand are often used inComputer Aided Design
(CAD) for their increasedprecision over a mouse.
-
7/22/2019 03a - Input Devices - Inputs
31/91
Touch sensitive pad
These are most
commonly found on
laptop computers.
A stylus or the usersfinger is pressed gently
onto the pad, and as it is
moved the cursor moves
on the screen.
-
7/22/2019 03a - Input Devices - Inputs
32/91
Joystick / Joypad
These are most commonly used to
interact with computer games,
although they are also used in other
circumstances (e.g. on hospital
scanners). Like the tracker ball, the movement
of the joystick moves the cursor on
the screen,
-
7/22/2019 03a - Input Devices - Inputs
33/91
Advantages They give a better
gaming experiencefor racing or flying
styles of computer
games
Disadvantages Some people find
joysticks more difficult
to control than atraditional mouse.
Joysticks are not
particularly robust and
can break easily if too
much force is used on
them.
-
7/22/2019 03a - Input Devices - Inputs
34/91
Light pen
Light pens are usually used
with specialist design
software.
The light pen works by being
touched against the screen.
As the pen is moved on the
screen, the cursor moves.
-
7/22/2019 03a - Input Devices - Inputs
35/91
Light PenLight Pen A light pen is a computer input device in
the form of a light-sensitive wand used in
conjunction with a computer's CRT TV set ormonitor. It allows the user to point to displayed
objects, or draw on the screen. A light pen is fairly
simple to implement. Just like a light gun, a light
pen works by sensing the sudden small change inbrightness of a point on the screen when the
electron gun refreshes that spot.
-
7/22/2019 03a - Input Devices - Inputs
36/91
Touch screen
The touch screen is a special type of
screen which is sensitive to touch.
Selections can be made by touching
the screen. These are particularly useful in banks,
building societies, and shops, where
customers who are not used to using a
keyboard can interact with a computer
system.
-
7/22/2019 03a - Input Devices - Inputs
37/91
Stylus Used on palmtopand tablet
computers where a flat screen
is pressure sensitive and
sends a signal ack to the
computer when it touched by a
plastic stick called a stylus.This is often used
with handwriting
recognition software to allow
the user to enter data. The
software is "taught" the shapesof letter that the user uses and
then as the user writes on the
touch screen the shapes are
interpretted into text.
-
7/22/2019 03a - Input Devices - Inputs
38/91
Advantages
Easy to use - intuitive,
don't need much training
No extra peripherals such
as a mouse are needed
Software can alter the
screen while it is being
used, making it more
flexible than a conceptkeyboard which has a
permanent overlay.
Disadvantages Not suitable for inputting large
amounts of data
Not very accurate - selecting
detailed objects can be difficultwith fingers
Tiring to use for long periods
More expensive than
alternatives such as a mouse
Not robust - can soon becomefaulty if misused
-
7/22/2019 03a - Input Devices - Inputs
39/91
Graphics tablet
A graphics tablet allowsthe user to create designsdirectly onto the screen.
A special stylus isconnected to thecomputer via the graphicstablet, and as the userdraws on the tablet with
the stylus the drawingappears on screen.
-
7/22/2019 03a - Input Devices - Inputs
40/91
-
7/22/2019 03a - Input Devices - Inputs
41/91
This has a flat surface that can sense the
slightest touch.
Artists and designers use it to enter drawings
into a computer system.
By dragging a stylus across the tablet surface
you can draw freehand and the drawing is
entered exactly into the computers memory.
-
7/22/2019 03a - Input Devices - Inputs
42/91
Advantages It is much more
natural to draw
diagrams with a
pencil typeimplement (the
stylus) rather than
with a mouse
A great level of
accuracy can be
achieved
Disadvantages Not really suitable
for general
selection work
such as pointingand clicking on
menu items
Graphics tabletsare much more
expensive than a
mouse
-
7/22/2019 03a - Input Devices - Inputs
43/91
-
7/22/2019 03a - Input Devices - Inputs
44/91
Sensors
Sensors are often used as part of afeedback cycle. They collect datacontinuously and are typically linked to
a control programthat specifiesacceptable levels, eg the minimum and
maximum temperature in a greenhouse. The control program decideswhat to do next based on the data it's
fed by the sensors.
http://www.bbc.co.uk/schools/gcsebitesize/ict/measurecontrol/0computercontrolrev3.shtmlhttp://www.bbc.co.uk/schools/gcsebitesize/ict/measurecontrol/0computercontrolrev4.shtmlhttp://www.bbc.co.uk/schools/gcsebitesize/ict/measurecontrol/0computercontrolrev4.shtmlhttp://www.bbc.co.uk/schools/gcsebitesize/ict/measurecontrol/0computercontrolrev4.shtmlhttp://www.bbc.co.uk/schools/gcsebitesize/ict/measurecontrol/0computercontrolrev4.shtmlhttp://www.bbc.co.uk/schools/gcsebitesize/ict/measurecontrol/0computercontrolrev3.shtml -
7/22/2019 03a - Input Devices - Inputs
45/91
Readers
The most common types of reader usedinclude
magnetic strip readers
barcode readers optical character readers/recognition,
magnetic ink character readers/
recognition optical mark readers/recognition).
-
7/22/2019 03a - Input Devices - Inputs
46/91
-
7/22/2019 03a - Input Devices - Inputs
47/91
Magnetic stripes are built into
many plastic cards such as debit
or credit cards and personal
identity cards.
The magnetic strip on the back of
the card can hold the personal
details of the card owner and,
with the necessary PIN, will allow
access to secure information, eg
bank account details.
Data stored on the strip is
scanned and input into a computersystem by a magnetic stripe
reader.
-
7/22/2019 03a - Input Devices - Inputs
48/91
The information printed on the
cheque using MICR is :
A unique number for the
cheque.
A code that identifies the bank
and branch that issued the
cheque.
The number of the account
that the cheque relates to.
MICR readers can only read
one special font which can
represent only numbers and a
few punctuation marks. They
can read characters very
quickly and with 100%accuracy. Information printed
in magnetic ink is also very
secure. It is not possible to
change the information by
writing over it with a pen andthe printed numbers are not
damaged by folding (as often
happens with cheques). Both
the reader used by MICR and
the special ink are expensive.
-
7/22/2019 03a - Input Devices - Inputs
49/91
Barcode readers
Barcodes are used in
shops, libraries,
luggage handling,
and stock control.
The lines on a
barcode represent
numbers, and can bescanned very quickly
using a laser
scanner.
-
7/22/2019 03a - Input Devices - Inputs
50/91
Barcodes are printed on nearly every product you buy,
each product has a unique code. When read,
information stored in the shop'sdatabase
is recalled,such as the product name and price. This information
later appears on your receipt. The scanning process
also assists in stock management, reducing the stock by
one each time a product is scanned/sold.
The information normally included on a bar code for a
product is country of origin, manufacturer and item code.
The price is not included in the bar code. A scanner can read a barcode number incorrectly. A check digitis
included in the barcode number to reduce the likelihood of this
happening.
http://www.bbc.co.uk/schools/gcsebitesize/ict/hardware/0inputandoutputdevicesrev2.shtmlhttp://www.hollyfield.kingston.sch.uk/gcseit/GCSE/validate.htmhttp://www.hollyfield.kingston.sch.uk/gcseit/GCSE/validate.htmhttp://www.bbc.co.uk/schools/gcsebitesize/ict/hardware/0inputandoutputdevicesrev2.shtml -
7/22/2019 03a - Input Devices - Inputs
51/91
Scanners
A scanner is a
device that
optically scans
images, printedtext, handwriting,
or an object, and
converts it to a
digital image.
-
7/22/2019 03a - Input Devices - Inputs
52/91
A scanner works by shining a light at the image beingscanned and measuring how much light is reflected back
using an optical sensor. The amount of light that is
reflected back tells the computer how light or dark the
image is at each point
-
7/22/2019 03a - Input Devices - Inputs
53/91
:- Image Scanners
(a)Flatbed scanners
(b)Handheld scanners
OCR (Optical Character
recognition) OMR (Optical Mark
Reader)
Bar code Reader
MICR (Magnetic InkCharacter Recognition).
Types of Scanners are
-
7/22/2019 03a - Input Devices - Inputs
54/91
Flatbed Scanner: You place the image on top of the scanner. Thescanner moves the light and sensor itself and scans the whole image
automatically. Most flatbed scanners are A4 size.Handheld Scanner: You must manually push the light/sensor along theimage. Handheld scanners are usually 5 inches wide.
-
7/22/2019 03a - Input Devices - Inputs
55/91
Optical Character Recognition (OCR)software can be used to
read printed text from an image that has been scanned and store it
as text rather than an image. You can then edit the text using a
word processoror desktop publisher. OCR software is not yetsophisticated enough to read hand-written text accurately.
Advantages
http://www.hollyfield.kingston.sch.uk/gcseit/GCSE/input.htmhttp://www.hollyfield.kingston.sch.uk/gcseit/GCSE/wproc.htmhttp://www.hollyfield.kingston.sch.uk/gcseit/GCSE/dtp.htmhttp://www.hollyfield.kingston.sch.uk/gcseit/GCSE/dtp.htmhttp://www.hollyfield.kingston.sch.uk/gcseit/GCSE/wproc.htmhttp://www.hollyfield.kingston.sch.uk/gcseit/GCSE/input.htm -
7/22/2019 03a - Input Devices - Inputs
56/91
Advantages
Flatbed scanners are very accurate and
can produce reasonably high quality
images
Any image which is digitised by thescanner can then be included on electronic
documents
Images once digitised can be enhanced
with a graphics application
Disadvantages
Images can take up a lot of memory
space
Images lose some quality in the
scanning and digitising process
The quality of the final image is
dependent on the quality of the original
image
Optical character
-
7/22/2019 03a - Input Devices - Inputs
57/91
Optical character
readers/recognition
Optical character recognition is a method ofinputting text using a scanner.
It requires special software to convert thescanned image of each letter into an ASCII(American Standard Code for InformationInterchange) code, and it often confuses similarshaped letters and numbers (e.g. S and 5, B and8).
It is used to convert paper books and documentsinto electronic files. When one scans a paperpage into a computer, it produces just an imagefile, a photo of the page.
-
7/22/2019 03a - Input Devices - Inputs
58/91
Magnetic ink character
-
7/22/2019 03a - Input Devices - Inputs
59/91
Magnetic ink character
readers/recognition
Branch codeCheque number Account number
-
7/22/2019 03a - Input Devices - Inputs
60/91
Magnetic ink characters appear at the bottom of cheques. Banks use
MICR to read the numbers from the bottom of cheques to obtain data
such as account numbers and bank sort codes. A particular fontis used
that makes it easy for the machine to discriminate between characters.
The ink is magnetised, this makes it immune to creases and dirty
marks.
http://www.bbc.co.uk/schools/gcsebitesize/ict/hardware/0inputandoutputdevicesrev2.shtmlhttp://www.bbc.co.uk/schools/gcsebitesize/ict/hardware/0inputandoutputdevicesrev2.shtml -
7/22/2019 03a - Input Devices - Inputs
61/91
Optical mark readers/recognition
Optical mark recognition sense marks
made on specially designed forms (e.g.
multiple choice answer sheets, lottery
cards). OMR is a very cheap, easy and quick to
handle system of inputting data, but if a
user makes a mistake they are difficult tocorrect.
-
7/22/2019 03a - Input Devices - Inputs
62/91
Optical mark readers/recognition
-
7/22/2019 03a - Input Devices - Inputs
63/91
An OMR reads marks made by pencil on a printed form into the
computer. OMR systems are suited to reading pre-printed forms and
check boxes such as National Lottery number selection sheets and
multiple choice exam papers.
Smart Cards
S d f ll d i d i I f h ll
-
7/22/2019 03a - Input Devices - Inputs
64/91
Smart cards are often called input devices. In fact they are actually
simple storage devices. A smart card contains a small RAMchip.
When the card is put into a machine data can be read from the card
or written onto it. A smart card can store much more data than amagnetic stripe can. A popular card in use at the moment can store
8k (about 8000 characters) of information.
http://www.hollyfield.kingston.sch.uk/gcseit/GCSE/strorage.htmhttp://www.hollyfield.kingston.sch.uk/gcseit/GCSE/strorage.htmhttp://www.hollyfield.kingston.sch.uk/gcseit/GCSE/strorage.htmhttp://www.hollyfield.kingston.sch.uk/gcseit/GCSE/strorage.htm -
7/22/2019 03a - Input Devices - Inputs
65/91
Petrol companies and supermarkets use smart
cards to store information about points that
customers earn when they buy goods. Every
time the customer buys something the numberof points stored on the card is increased. The
customer can then spend these points to buy
goods.
-
7/22/2019 03a - Input Devices - Inputs
66/91
-
7/22/2019 03a - Input Devices - Inputs
67/91
A new generation of smart cards is now
appearing which contain a small
microprocessoras well as memory. These
cards are practically a complete computersystem on a card.
http://www.hollyfield.kingston.sch.uk/gcseit/GCSE/compsys.htmhttp://www.hollyfield.kingston.sch.uk/gcseit/GCSE/compsys.htm -
7/22/2019 03a - Input Devices - Inputs
68/91
Punched cards and tape
Punched cards and tape were used by the
first computers to store programs and
data.
They are seldom used today except forclock cards, which records when a person
starts and ends work, and Kimball tags,
which are used for stock control.
-
7/22/2019 03a - Input Devices - Inputs
69/91
-
7/22/2019 03a - Input Devices - Inputs
70/91
Sound capture devices
Voice recognition software remembersthe way a user speaks, and converts theirspeech into text that appears on screen.
Although voice recognition software hasbecome increasingly sophisticated, manysuch programs have difficulty convertingmore than 90% of common words
accurately.
-
7/22/2019 03a - Input Devices - Inputs
71/91
Microphone
The sound is detected by the microphone
and an electrical signal is transmitted to the
computer.
Special hardware is used to convert thisanalogue data into digital data so it can be
stored and manipulated.
-
7/22/2019 03a - Input Devices - Inputs
72/91
Voice Recognition Voice recognition systems listen to what
people are saying and carry out the
instructions given to them when peoplespeak.
-
7/22/2019 03a - Input Devices - Inputs
73/91
Existing voice recognition systems come in
two different types :
Systems which recognise only a few
words but can understand most peoples
voices. e.g. telephone banking computers.
Systems which recognise a wide
vocabulary but need to be trained to
understand each different voice. e.g.
automatic dictation systems.
-
7/22/2019 03a - Input Devices - Inputs
74/91
-
7/22/2019 03a - Input Devices - Inputs
75/91
Digital Cameras
Digital camera A digital camera takes pictures and can
usually record video too. The pictures it
takes and the videos it records are storedin files. These files can be copied to a
computer and later edited.
-
7/22/2019 03a - Input Devices - Inputs
76/91
C S
-
7/22/2019 03a - Input Devices - Inputs
77/91
WEB CAMS
Webcams are very basic digitalvideo cameras used to capture
images to be sent down networks
for video conferencing.
Webcams do not allow you to savethe images like digital video cameras
do. Video conferencing is where
people can "meet" across a network
using microphones, webcams andmonitors. This lets people meet who
are different countries meet.
-
7/22/2019 03a - Input Devices - Inputs
78/91
Video Digitiser A video digitiser takes an image from a video
camera or television and converts it so that it
can used by and stored on a computer. Almost
all video digitisers now work in colour. Unlike
scanners video digitisers can capture movingvideo sequencesas well as still images.
-
7/22/2019 03a - Input Devices - Inputs
79/91
When a video sequence is captured thecomputer stores this as a sequence of still
images called frames. These images aredisplayed quickly one after the other(rather like a flick-book) to create the
illusion of a moving picture.
-
7/22/2019 03a - Input Devices - Inputs
80/91
When you want to capture a videosequence you must tell the computer :
Size: How big you want the image youcapture to be. e.g. should it take up thewhole screen, 1/2 the screen, 1/8th of the
screen ... ?
Frame Rate: How frequently the framesshould be captured from the video.
T i l
-
7/22/2019 03a - Input Devices - Inputs
81/91
Terminals
EPOS (Electronic Point Of Sale) andEFTPOS (Electronic Fund Transfer at
Point Of Sale) terminals are connected,
via secure Internet connections, to thecomputers of the main banks and credit
card companies.
-
7/22/2019 03a - Input Devices - Inputs
82/91
T i l
-
7/22/2019 03a - Input Devices - Inputs
83/91
Terminals
It also gives the retailer an opportunity tocollect information about their customers,
and to develop individual customer profiles
(i.e. know what an individual customermay want to buy).
This helps to retailer to target individual
customers with special offers etc.
Di it l i i d i
-
7/22/2019 03a - Input Devices - Inputs
84/91
Digital imaging devices
These include video digitisers, scanners,digital cameras, and web cams.
Vid Di iti
-
7/22/2019 03a - Input Devices - Inputs
85/91
Video Digitisers
The video digitiser is a combination ofhardware and dedicated software thatconverts an analogue signal into a digital
signal. This is the basis of most set top boxes thatgive access to digital television onstandard television sets.
It can also be used to capture still imagesfrom video.
Di it l
-
7/22/2019 03a - Input Devices - Inputs
86/91
Digital cameras
Digital cameras convert the analogueimage seen through the cameras lenseinto a digital signal that can be stored.
Each picture is split up into millions of tinysquares (or pixels), each of which is adifferent colour.
Each pixel is stored as a bit of digitalinformation.
W b
-
7/22/2019 03a - Input Devices - Inputs
87/91
Web cams
Web cameras (web cams for short) aresmall digital cameras which are attached
to computers so that still and motion digital
images can be captured and used. They are often used in conjunction with
the Internet so that people can
videoconference.
T l d i
-
7/22/2019 03a - Input Devices - Inputs
88/91
Tonal devices
Touch tone telephones are the mostcommon tonal device used to input data.
Customers can use them to interact with
computerised telephone systems so thatthey can respond to choices given to them
by recorded messages.
-
7/22/2019 03a - Input Devices - Inputs
89/91
-
7/22/2019 03a - Input Devices - Inputs
90/91
-
7/22/2019 03a - Input Devices - Inputs
91/91