Guidelines

Checklist for Computer Hardware

No significant benefits  Minor benefits  Major benefits
Controls
The surface of the controls does not contain any material which may cause an allergy
Controls are operable with one hand
Controls are placed so that they are easily reached by a person in a wheelchair
Controls are well spaced so that they are not activated by mistake
Controls are tactilely discernible without activating them
Controls are tactilely marked so that control setting is easily identified
Audio or tactile feedback is provided for activation of controls that do not have any physical travel
The size, shape and surface of controls are easily grasped
Labels are of high contrast, clear and as large as possible
Operation of a control should not require more than 2 Newtons*
Push button controls require less than 100 grams of pressure**
Keyboards and Keypads
All commands and option can be accessed by using the keyboard
The keyboard should be detachable and have a sufficiently long cable, so it can be placed according to user's needs
The keyboard is of low-profile type, i.e. the height of the key-row beginning A-S should not be greater than 30mm.
There is good friction between the keyboard and the desktop
The key tops are matt
The surface of the keytops is concave
The user receives tactile and audible feedback when pressing a key
Groups of keys are separated by distinct spaces
Groups of keys are distinguished by different colours
The F, J and 5 keys are marked with a tactile identification
Frequently used keys, such as Enter, Shift, Escape, Ctrl, Backspace etc. have a shape that differs from other keys
There is high contrast between the colour of the character and the background of the keytop
The height of the characters is not less than 4mm
The text on the keys should be printed in sans-serif font
Text is not printed in red or green
The user can customise the keyboard with respect to features such as repeat rate, key activation delay, delay between acceptance of two consecutive key presses, minimum time for pressing a key before the key repeat begins, and serial instead of multiple simultaneous keystrokes etc.
If key repeat is supported, the delay before repeat should be adjustable to at least 2 seconds per character
If sufficient space is available, shift keys (upper and lower case, ctrl, alt etc.) should be duplicated, one on each side of the keyboard, and be placed symmetrically
The system allows the connection of two keyboards, which could be used simultaneously
The power to press a key should be between 0.3 and 0.6 Newton***
Pointing devices
The user can execute pointing functions from the keyboard
The user can modify cursor speed, distance and double-click interval
Operation of a pointing device does not require two simultaneous hand movements
The power needed to operate a pointing device should be between 0.3 and 0.6 Newton
Drives and removable media
Mechanisms for inserting and removal of drives and removable media should require a minimum of muscular strength, range of motion, reach and movement precision
The user is alerted of incorrect insertion
Displays
Screens should have a frequency greater than 2Hz and lower than 55Hz to avoid flicker
The typeface should be clear and legible
The display has good contrast
Glare on the display is minimised
The display can be separated from the device so it can be placed in an accessibile position or replaced by another better suited to the user's needs
The display provides an easy mechanism for altering its angle, height etc.
Colour and contrast
Users can select and adjust the colours and contrast used on the display
Audio output
Audio output is supplemented by captioning or subtitles
Signals from the basic system, such as alarms, warnings, status lamps and error messages are available in alternative forms
The volume, pitch and frequency of signals from the basic system, such as alarms, warnings, status lamps and error messages are adjustable
The volume can be reset to a default level
Warnings and similar alert messages must remain stable for a sufficiently long time to be discovered by the user
Internal speaker units are located at the front of the computer and directed towards the user
An industry standard connector for headphones or personal listening devices is provided
External connections
Tactile indication is provided on any plug or insert and its corresponding connection point
A bevel around the slot or connection point is provided
Serial and parallel interface connectors, data buses, keyboard connectors and other data transfer mechanisms such as infrared technology or radio, follow existing standards or de facto standards
Connection points e.g. USB ports are located on the front of the computer
Peripheral devices
A system purchased with the expectation that it will now or in the future be used by a user who needs an assistive device should have the maximum number of serial ports, parallel ports and expansion slots
Instruction manuals / documentation
Simple, clear concise language is used
There is a table of contents and an index
The instructions are task orientated
Information is available in alternative formats
Documentation is provided in alternate modes of delivery (e.g. fax, Internet, email)
A good legible typeface is used
Information contained in pictures is also explained in the text

*According to the Nordic Cooperation on Disability (1998) operation of a control should not "require more power than 2 Newton". See Computer Hardware guideline for references.

** The Design Considerations Task Force of the Industry/Government Cooperative Initiative on Computer Accessibility (1988) states that push button controls should require "less than 100 grams of pressure". See Computer Hardware guideline for references.

***According to the Nordic Cooperation on Disability (1998) the power to press a key should be "between 0.3 and 0.6 Newton". See Computer Hardware guideline for references.

Checklist for Controls
Checklist for Displays
Checklist for Keys

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