Re: Vision impaired interface

From: Edward Cherlin <edward_dot_cherlin_at_etssg_dot_com>
Date: Fri Oct 31 2003 - 09:41:46 CST

On Thursday 30 October 2003 02:25 pm, Alan Dechert wrote:
> Jan,
> A lot of blind people know how to type. So we should have a
> regular keyboard (maybe there is a special one?) available so
> they can type in the names.

We will have to ask the specialists in the blind and visually
impaired community what they need, want, and expect. Shawn Casey
O'Brien, Executive Director, Unique People's Voting Project, is
our principal contact with that community, and a passionate
advocate for them. I also have contacts in the Peninsula Center
for the Blind and Visually Impaired, which I expect will be
delighted to provide testing facilities and test subjects, in
addition to expertise. (I have more than fifty years of family
and other background in this, through my aunt Mary Cherlin (no
longer with us) and a close family friend, Edna Bartram, who is
entirely blind from birth and runs a bed and breakfast in Rhode
Island. My father, my uncle, and my mentor in Buddhism went
blind with cataracts.)

Common Braille keyboards have six keys corresponding to the six
dots in ordinary Braille. Users type chords. There is also an
8-dot Braiile, and 8-key Braille keyboards such as the Braille
Light 40 from Freedom Scientific.

(Both the 6-dot braille symbols and the 8-dot Braille symbols are
in Unicode. Braille is a stateful writing system in which each
symbol has multiple interpretations depending on the current
mode. Single symbols can represent single characters, words, and
phrases in different contexts. The sets of interpretations and
even the sets of modes are different in the various national
Braille systems, especially those for non-Latin alphabets and
Chinese characters.)

The same key-per-dot technique can be used on a standard keyboard
by designating SDF JKL or ASDF JKL; (AOEU HTNS on a Dvorak
layout) as the Braille keys. This requires a low-level keyboard
driver that can handle up to six or eight keys pressed at once.
The driver needs to have appropriate logic to accumulate key
events, returning the key combination after the last key-down
event in a sequence, but waiting to do so until after all the
corresponding key-up events.

Duxbury's Megadots product is such a system for Windows.

"The braille keyboard (or Perkins keyboard) uses the keys
SDF--JKL as keys on a braillewriter keyboard. For example,
pressing down F and J simultaneously and then letting go enters
the character for dots 1-4, which is the letter 'c'. If you have
a top menu bar, you will notice a <6> in the upper right corner
when Perkins keyboard mode is on.

"Braille keyboard mode depends on a program called BKEYSDRV."

There are Braille "displays", too, on one-line or full page pin

Freedom Scientific

Products and Services
Personal notetaking, Braille embossing, computer Braille displays
and scanning & reading printed media.

> Alan D.

Edward Cherlin, Simputer Evangelist
Encore Technologies (S) Pte. Ltd.
Computers for all of us,
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Received on Fri Oct 31 23:17:06 2003

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