An overlay keyboard is a shallow rectangular plastic or metal box, usually A4 or A3 size, with a flat
top surface. The overlay keyboard plugs into the computer and it is used to operate it in place of the
computer keyboard.
The overlay keyboard surface consists of a number (usually between 128 and 4096) of
touch-sensitive keys. Individual keys, or groups of keys, may be programmed to:
• produce letters, words or phrases;
• emulate the action of pressing keys on the keyboard;
Paper or plastic overlays are placed on top of the keyboard to show the user which keys and areas
have been programmed on the keyboard. The overlay can have text, symbols, photographs or objects
– anything that reflects the action of the key(s) underneath in a way that is meaningful for the user.
Figure 5-2 shows an overlay for Discover:Board. The overlay can generate letters, numbers and
control keys; move the mouse pointer and click the mouse button; select blocks of text and then ‘cut’,
‘copy’ and ‘paste’; save to disc and print; spell-check the document; and speak out blocks of text.
This particular overlay is North American: British schools would probably wish to modify it to use
lower-case text.
Figure 5-2 Discover:Board overlay for Write Outloud talking word processor
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Chapter 5 Using Overlay Keyboards
Who Might Use an Overlay Keyboard?
The main advantage of overlay keyboards is that dedicated overlays can be tailored to suit the
individual user and a particular task, thereby simplifying and improving access and control. Their use
is not confined to special needs: overlay keyboards are used as input devices for retail, stock control
and automatic cash machines – wherever a limited set of options needs to be presented.
Physical / Perceptual Difficulties
Pupils with physical or perceptual difficulties who find it hard to press the small keys on a standard
keyboard may be able to use overlay keyboards with overlays designed to suit their particular needs.
For example, the keys can be made different sizes, spaced further apart and arranged in a helpful
layout, say with common keys grouped together.
Visual Impairment
Pupils with visual impairment may benefit from overlays created in high contrast colours (e.g.
yellow on black); with large letter sizes; or clear space around each key.
Young and Early Learners
Young and early learners who are unfamiliar with the standard ‘QWERTY’ layout may find the
full keyboard confusing. Overlay keyboards with keys printed in a lower case or ‘primary
handwriting’ font or arranged in alphabetic order (Figure 5-3) may be simpler and easier to use.
Figure 5-3 IntelliKeys alphabetic layout
Overlays can be created with layouts and functions matched to the target application. For example,
the Discover:Board overlay shown below can be used to control the mouse pointer for
‘point-and-click’ programs.
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Chapter 5 Using Overlay Keyboards
Figure 5-4 Discover:Board Mouse control overlay
Reading Difficulties
Early readers/writers or users with specific learning difficulties can use overlay keyboards to
produce whole or part words and phrases, with a single keypress. This allows a student to practice
sentence formation without having to worry about the spelling of individual words. Different
overlays can be created to suit the current curricular topic. The Concept Universal overlay below is
for use with the Wellington Square reading scheme.
Figure 5-5 Wellington Square overlay
Overlays are not limited to letters and words – anything can be drawn, printed or glued on the
overlay. Non-readers can select photographs, pictures or symbols as well as, or instead of, text.
Figure 5-6 Concept Plus overlay
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Chapter 5 Using Overlay Keyboards
5.2 Choosing an Overlay Keyboar d
Different keyboards are available in different sizes and with different features. Most keyboards need
special software in which case you cannot consider the keyboard without also considering its
accompanying software and the curriculum software that it needs to access. Software is discussed
later on; we’ll look at the ‘basics’ of the keyboards first.
Size
The size of the keyboard and overlay area is important:
Larger keyboards (e.g. A3 size) are useful for:
• group work where several children can use it at once;
• designing overlays with lots of keys, showing larger pictures and text;
• use by children who have difficulty targeting small keys.
The smaller keyboards may be more suitable for young children and those who have limited range of
movement.
The British-made Concept Keyboards take A3 or A4 size overlays which are convenient for making
up overlays since paper is readily available. The North American devices have different overlay sizes
so you have to buy special paper from the keyboard suppliers or cut the overlay to shape.
Number of Individual Keys
The keys on most of the keyboards are approximately 1 or 2 cm square. This means the overlay
picture areas are big and ‘blocky’ – fine for letters and word banks but not so good for detailed
pictures or maps. Informax has 4096 individual keys so that very fine detailed overlays can be
designed.
Computers, Connections & Keyguards
Different keyboards work with different computers and need different plugs and leads. These are
described in more detail later. Keyguards are helpful for children who press keys by mistake (see
Chapter 3Accessing the Keyboard for more information about keyguards).
Cost
The prices given in the Table 5-1 are for the keyboard only. The Concept keyboards need software as
well (see Table 5-2 for driver software prices).
Overlay Keyboards
‘Concept’ Keyboards
• ‘Old blue’ Concept Keyboard
These keyboards were originally designed for the BBC micro in the early 1980s, and are still
commonly used in schools. They have a flat ribbon cable which plugs into the User or Parallel
port on BBCs. They can also be plugged into RM Nimbus 186, RM 386 ‘M’ series and Acorn
machines fitted with optional User Ports. The keyboards were available in A4 or A3 sizes with
128 keys. A large amount of good educational software was written for the Concept Keyboard,
and much of it is still in use. The Concept Keyboards can also operate the more recent software
written for Concept Universal boards.
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Chapter 5 Using Overlay Keyboards
• Concept Universal
The Concept Universal has been developed from the original old blue Concept Keyboard. They
are available in A4 or A3 size, with 256 keys. They are supplied with one connecting cable for
the computer of your choice: you can buy extra cables for other computers separately. The cables
are either the parallel type (for plugging into BBC, Acorn or Nimbus User Port) or the serial type
(for plugging into a PC ‘COM’ port, Acorn serial port, or Macintosh Printer/Modem ports). The
keyboards have ‘key beep’ and ‘auto-repeat’ options.
• Concept Universal Plus
A new version of the Concept Universal with a more attractive and comfortable case. It has nonslip feet, holds overlays more securely, and has screw fixings for mounting. A version with an
infra-red link, instead of the cable, is available. This keyboard can operate the same software as
the standard Concept Universal.
• Touch ‘N’ Go
Touch ‘N’ Go is approximately A5 size (half A4), has 256 keys, and uses standard Concept
Keyboard software. It connects to the computer with a cable or infra-red link.
• Informatrix 2
Informatrix is a ‘high-resolution’ version of the A3 Concept keyboard, with 4,096 keys instead of
256. More and smaller keys means you can design overlays with more accurate areas for detailed
pictures and maps. The board can be used with the same overlays and software as the other A3
size boards (with up to 256 keys), but Informax software must be used if more than 256 keys are
required. Informatrix uses the same serial cables as the Concept Universal to plug into Acorn,
Macintosh or PC computers. It has key beep and auto-repeat options.
• Keyguards and accessories
Keyguards for A3 and A4 Concept Keyboards are available with 2, 4, 6, 12 and 32 holes. The
Concept Lynx can give switch users access to concept keyboard software. It is a small box with
four switch jack sockets; when a switch is pressed the software acts as though a key has been
pressed on the Concept Keyboard.
• Concept Keyboard software
The Concept keyboards all need special driver or emulator software (such as Informax, Concept
Plus/Concept Plus Multimedia, or Conform+) which recognises when a key has been pressed and
then carries out the programmed operation on the computer. You can use the software to create
your own overlays and programme the keyboard to work with particular applications. Most of the
programs let you programme the keyboard to generate text, operate the control keys; move the
mouse pointer; and play digitised sound. Concept Plus Multimedia is an extension to Concept
Plus which lets you create multimedia activities, with recorded sound, synthesised speech and
video clips, with matching overlays. Some educational software already has the Concept
Keyboard driver built-in (such as Writing with Symbols and Making Tracks to Literacy from
Widgit, and some My World screens).
IntelliKeys
IntelliKeys has 576 keys and plugs into a Mac or PC keyboard connector in place of the standard
keyboard; no special software is needed. It gives full control over the computer, including control
over the mouse pointer and access to menus and dialogue boxes. It comes with seven ready made
standard overlays: full QWERTY keyboard and mouse control; alphabetic; numeric; large mouse
overlays; ‘setup’ for programming the keyboard response. It also has two 3.5mm jack sockets for
switch users so can be used as a programmable switch interface. There are keyguards for the
seven standard overlays and a range of keyguards for custom overlays, with 2, 3, 4, 6, 9, 12, 15
or 20 holes. There is a range of educational software which is supplied with ready-made
overlays. You can buy ready-made software and overlays to access Edmark software such as
Bailey’s Book House and Millie’s Math House. Custom overlay files and overlays for computer
- 78-
Chapter 5 Using Overlay Keyboards
control can be designed with a separate Overlay Maker program. IntelliPics is a multimedia
program for creating early learning activities with sound and animation, and corresponding
overlays, for access with IntelliKeys.
Key Largo / Ke:nx
Key Largo is an overlay keyboard for Macintosh. It needs a Ke:nx interface and software to work
and the total cost of both is very high compared to other overlay keyboards. The keyboard is
slightly larger than A4 and uses ‘US legal’ size overlays. The Ke:nx software provides full
control over the Macintosh keyboard and mouse as well as digitised and synthetic speech. Many
ready-made overlay files (called setups) are available for popular educational software packages.
Discover:Board / Ke:nx On:Board
Discover:Board (and the previous version Ke:nx On:Board) is an overlay keyboard that plugs
into the Apple ADB keyboard/mouse port. It can be used with desktop computers or slides over
an open Macintosh Powerbook and uses Ke:nx software to give full access to the Macintosh.
Five overlays are supplied, with QWERTY, alphabetic, mouse control, numbers and multimedia
layouts and new files and overlays can be made using the software supplied with the board. As
well as good computer control, Discover:Board can be used to generate synthetic or digitised
speech using the Mac’s built-in sound software. Keyguards with 32, 64 and 128 holes are
available. There are ready-made curriculum activities and overlays for popular educational CD’s.
Others
The Saitek PCDash is a small overlay keyboard designed mainly for playing games on PC. It
comes with ready-made overlays for games like Quake, plus one for controlling MS Word
toolbars, and you can also design and print your own. It has 35 keys on the overlay, an eight-way
‘game-pad’; 2 fire buttons, and 3 programmable buttons. It is £49.95, from KCS and some
computer suppliers.
Electrone manufacture a range of overlay keyboards (‘Keyport Touch Panels’) with 60 to 300
keys, for industrial, sales and healthcare applications. They are slightly larger than A4 size and
are user programmable. They cost between £125 and £349.
Table 5-1 Overlay Keyboards
Overlay Keyboard Overall
Acorn, BBC, Mac,
Nimbus, PC
Concept
Universal A3
(A4)
Acorn, BBC, Mac,
Nimbus, PC
Concept
Universal Plus
A3 (A4)
Acorn, BBC, Mac,
Nimbus, PC
Touch ‘N’ Go
Acorn, PC
Informatrix 2
Mac, PC
IntelliKeys
size cm
52 x 33
(39 x
24)
52 x 33
(39 x
24)
28 x 10 24 x 16
39 x 24
44 x 26 33 x 22
Overlay
size cm
42 x 30
(30 x 21)
42 x 30
(30 x 21)
42 x 30
(A3)
No. of
keys
256
- 16x16
256
- 16x16
256
- 16x16
4096
(64x64)
576
(24x24)
Connects
to...
Parallel or
serial port
Parallel or
serial port.
Infra-red
serial link
Serial cable
or Infra-red
serial link
Serial port
Keyboard
port
Keyguard
& price
2, 4, 6, 12,
32 holes,
£25 each
2, 4, 6, 12,
32 holes,
£25 each
-
2, 4, 6, 12,
32 holes,
£25 each
14 different
types, £25
to £39 each
Price
Guide
£109
£129
(£177 for
infra-red)
£169
(£199 for
infra-red)
£129 SEMERC
£239
Supplier
SEMERC,
Inclusive
Technology,
Concept
Keyboard Co.
SEMERC,
Inclusive
Technology,
Concept
Keyboard Co.
Concept
Keyboard Co.
KCS,
SEMERC,
Inclusive
Technology
- 79-
Chapter 5 Using Overlay Keyboards
Overlay Keyboard Overall
MAC
Discover:Board
MAC
Key Largo
size cm
39 x 29
41 x 30
Overlay
size cm
36 x 22
(US
legal)
36 x 22
(US
legal)
No. of
keys
128
(16x8)
128
(16x8)
Connects
to...
ADB
keyboard
port
Ke:nx
interface
Keyguard
& price
128, 64, 32
holes, £75
each
128, 64, 32
holes, £75
each
Price
Guide
£395 Don Johnston
£215 +
£554 for
Ke:nx
interface
Supplier
Don Johnston
Overlay Keyboard Software
Most of the overlay keyboards need software in the computer to make them work:
• Keyboard Drivers & Editors. The keyboard driversoftware recognises when a key on the
overlay keyboard is pressed and then inserts text, moves the mouse, or performs some other
operation on the computer. (IntelliKeys is an exception – it plugs straight into the computer and
can be used immediately.)
• Overlay File. The keyboard driver needs an overlay file (also called selection set or setup) which
defines what each key does when pressed. Different overlay files are used for different programs
and different purposes.
• Overlay Editor. Overlay files are created using an overlay editor program. Most overlay
designer programs can also print out a paper overlay to match the overlay file.
Accessing Curriculum Software
There are several categories of educational software which are accessible with an overlay keyboard:
• Specifically designed software with driver for an overlay keyboard built in. Overlay files and
matching paper overlays are supplied with the program. Everything is supplied ready to use so no
programming is required. However, you are usually stuck with the overlays and activities offered
by the program and the content is generally fixed. ClarisWorks templates, some My World support
packs, Discover Curriculum Overlays and the IntelliKeys Hands-on programs are examples of
programs designed for overlay keyboards. Space does not permit a full listing of all the programs
that have an option of overlay keyboard access – see the MicroScope Concept Keyboard Special
issue and catalogues from the suppliers listed at the back of the book for reviews and programs.
• Content free software with optional overlay keyboard access. Usually a ‘starter set’ of overlay
files and overlays are supplied with an overlay editor. The Full-Phase+2 word processor from
SEMERC is one example.
• Keyboard drivers/emulators let you use the keyboard with any program running on the
computer. Once a suitable overlay file is created the driver program operates the computer as
though the ordinary keyboard or mouse were being used. These programs have considerable
flexibility and they are particularly useful in integrated settings where the overlay keyboard user
can get access to the same software that is being used by the rest of class. Creating overlays files
and overlays for individual pupils and curriculum tasks is time-consuming, although most
programs come with a selection of ready-made files and overlays.
Overlay keyboard Software Features
Price and supplier details of overlay keyboards are listed in Table 5-2; Table 5-3 gives the features of
each program:
• Text. All the programs can insert text into an application on the computer.
• Control, Modifier and Cursor keys. All can generate control key combinations – for example,
pressing ‘b-P’ to print a document.
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Chapter 5 Using Overlay Keyboards
• Sticky Keys. Most programs have Sticky Keys for people who cannot hold down two keys at
once: the Shift or Control key is pressed first, then a letter key pressed next (see Chapter 3 Accessing the Keyboard for a full description of sticky keys).
• Mouse Pointer Control. Control of the mouse pointer is a very useful feature as many pupils
who have difficulty with a standard keyboard also have problems with a mouse.
• Auditory Feedback. The keys on an overlay keyboard do not move or click when pressed so
there is little feedback that a key has actually been activated. Most keyboards or programs give
an auditory beep to confirm when a key is pressed. This is helpful for users with visual
impairments, learning difficulties, or physical access problems.
• Digitised sound. Some programs let you use the keyboard to play back digitised recordings or
sound or speech.
• Speech Output. Programs which can generate synthetic speech, instead of, or as well as, text
can be useful to support literacy and writing or for interpersonal communication.
• Keyboard Response. Sometimes it is important to be able to adjust the response of the
keyboard (see Chapter 3 Accessing the Keyboard for a description of the various adjustments),
so the table shows which facilities are offered with each program.
• Print-out Overlay. Programs with facilities for creating and printing paper overlays ready to be
used with new overlay files can save considerable time and effort.
Table 5-2 Overlay Keyboard drivers
DRIVER SOFTWARE Overlay
Acorn, Windows P C
Informax
Mac
Intercept
Windows PC
Concept Plus
Windows PC
Concept Plus
Multimedia
Mac, Windows PC
Intellikeys
Mac, Windows PC
Overlay Maker
Mac, Windows PC
IntelliPics
Mac
Discover/ Ke:nx
Refer to the suppliers’ c at alogues for further details
Keyboard
Concept
Keyboards
Concept
Keyboards
Concept
Keyboards
Concept
Keyboards
Intellikeys
Intellikeys
Intellikeys
Discover:Board
Ke:nx On:Board
Key Largo
Comment Price Guide Supplier
Flexible software with good
emulation features.
Similar to Designer, but has multiple
‘layers’ e.g. lower & upper case
For making and printing overlay fi l es
and overlays.
Concept Plus with sound, speech,
video and a multimedia presentation
program
Authoring program for designing
multimedia ac t i vities and matchi ng
overlays
Software for making custom overlays
for IntelliKeys.
Software for creating mult i media
activities for IntelliKeys keyboard
Very comprehensive emul at i on and
speech output features
£29 (free or
£4 if bought
with board)
£30
£60 (£14 if
bought with
board)
£95
free with
keyboard
(£239)
£49
£75
Supplied
with board
(boards from
£350)
SEMERC,
Inclusive
Technology
Concept
Keyboard Co.
AU
Enterprises
AU
Enterprises
KCS, Semerc,
Inclusive
Technology
KCS, Semerc,
Inclusive
Technology
KCS, Semerc,
Inclusive
Technology
Don Johnston
- 81-
Chapter 5 Using Overlay Keyboards
Table 5-3 Overlay Keyboard driver software features
DRIVER SOFTWARE
BBC
BBC Concept
Acorn
Conform+
Acorn, Windows P C
Informax
Mac
Intercept
Windows PC
Concept Plus
Windows PC
Concept Plus
Multimedia
Mac, PC
Intellikeys
Mac, PC
Overlay Maker
Mac
Ke:nx
Overlay
Keyboard
Text
Control, Modifier
& Cursor Keys
Mouse Control
Input Acceptance Filter
Concept
Keyboards
Concept
Keyboards
Concept
Keyboards
Concept
Keyboards
Concept
Keyboards
Concept
Keyboards
Intellikeys
Intellikeys
Key Largo,
Discover:Board
Ke:nx On:Board
Post Acceptance Filter
Repeat Filter
Sticky Keys
Auditory Feedback
Digitised sound output
Speech output
Print-out Overlay
Which overlay keyboard is best?
To choose an overlay keyboard you have to specify the functions needed by the user, the curriculum
and learning tasks, and then select the most appropriate combination of hardware and software. Cost,
the computer and software that you want to use, and the ease of use of the keyboard and software are
also key issues.
• Acorn
The most popular overlay keyboards for Acorn RiscOS computers are the Concept Keyboards with
either Informax or Conform+ software. If you wanted to create overlays for detailed pictures or maps
then the Informatrix with 4096 keys, with Informax software, would be the best choice.
It is possible to plug in the IntelliKeys device into A7000 or RiscPC machines as they have ‘PS/2’
keyboard connectors, but you can only use the standard overlays – the OverlayMaker software does
not run on Acorn RiscOS.
• Macintosh
If you were working on a particular curriculum topic and using a program like ClarisWorks
Templates on a Mac, then the Concept Universal might be most suitable as the Templates are
supplied with ready-made overlays, and the keyboard itself is cheap.
But if you wanted an overlay keyboard to work with all programs on the Mac, and replace all the
functions of the standard Macintosh keyboard and mouse, you might choose Intellikeys or
Discover:Board in preference to the Concept Keyboards with Intercept software, because the latter
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Chapter 5 Using Overlay Keyboards
has very limited features (it does not let you control the mouse pointer, for example).
Discover:Board has a more sophisticated set of computer control functions than IntelliKeys, while
IntelliKeys has better tools for designing overlays and associated activities (eg. IntelliPics &
OverlayMaker). Therefore, Discover:Board may be a better choice if you want a keyboard to give
the user independent control over the computer and easy access to common programs; while
IntelliKeys has the advantage for creating your own educational activities.
• Windows PC
A Concept Keyboard with Informax or Concept Plus software gives good computer control at a low
price. The infra-red versions of the Concept Universal Plus and Touch ‘N’ Go are good choices for
wheelchair users because no connecting cable is needed.
IntelliKeys has more facilities and features (switch sockets; better control over keyboard response),
but at a higher cost.
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Chapter 5 Using Overlay Keyboards
5.3 Further Information
Web Sites
Concept Keyboard Company http://www.conceptkey.co.uk The Concept Keyboard and accessories site.