🚀 go-pugleaf

Dan_Jacobson@ATT.COM writes:

>Hello.  Has anybody got ideas for using mainframe UNIX or computers in
>general for a disabled person with use of only the right hand?  ...
> [ also asks about text editors ]

I think I'm getting Carpal Tunnel Syndrome, so I'm building myself
a chord keyboard.  This consists of 5 buttons on a flat mounting,
one for each digit.  I'm adding a space bar.  I'm mounting it in a
5"x7"x1" project box.  I'm interfacing it all to an IBM PC.

With an IBM PC parallel port, pull an open switch to ground and a closed
switch to 5V.  Run all 6 switches through a 7405 hex open-collector inverter,
wire-NOR all the outputs, and you get a switch-down interrupt line on 
the parallel port.  (The interrupt handler has to poll until a switch
goes up.  You can avoid this inefficiency with many chips instead of one:
debounce the switch inputs, sample&hold all switch-downs, any interrupt on
any switch-up.  I'm too lazy to do all this design & wiring.)

Now for graphics input:
Get a Konami Nintendo-compatible ZapGun Helmet ($40).  The Nintendo ZapGun is
a light pen with a narrow lens in the barrel.   The Konami Helmet puts
the lens in a monocle, and a binary switch in a microphone.  Any noise
closes the switch.  You also get stereo headphones.  You should be able
to interface the light pen to real, IBM-compatible Hercules, CGA, and EGA
display adapters.  One VGA chip manufacturer, Cirrus (Fremont, CA)
claims to support light pens.  I'm researching this one.

You won't be able to draw free-hand with such a head-mouse, but you should
be able to select screen buttons.

An alternative for graphics input is something underfoot, if the
disabled person has use of the peds.  The IBM joystick card gives
your 4 switch inputs and 4 resistor A-D inputs.

Dr. Douglas Englebart, inventor of the chord keyboard, mouse, 
WIMP interface, and many other things, claimed in a recent seminar
that the chord keyboard group ran a big experiment to determine the
difficulty of learning a chord keyboard.  They hired a bunch of
office temps and carefully did the whole experimental-control group
protocol.  One group got special hands-on training, the other group
got written instructions and were left alone.  Both groups were keying
away madly in 2 hours, and the experiment was a washout.  Chord keyboards
are easy.

Dr. Englebart sat there chording with his left hand, mousing with his
right, and talking simultaneously, showing off a really slick hypertext
system his group wrote 25 years ago.  It was very impressive.

Good luck,

Lance Norskog