"Tony Smith" writes:
>Actually, the big sellers are the ones who get both right, current example
>is the Apple iPod.

	I have thought a lot about the philosophy and technology of
design.  As one who was born blind in the early fifties, I well
remember life before things got as electronic as they are now.  It is
certainly a mixed bag.  Before the mid seventies, I knew I could
always use a telephone, tune a radio or television to the right
channel or operate any sort of home entertainment gear or AV equipment
since the controls and us formed a nice closed loop.  The TV channel
selector clicked once for each channel with the only possible problem
being that of finding the position at which one went from the
highest-numbered channel back to the lowest one.  In North America,
that was VHF Channel 13 with the next click being the UHF band or
Channel 2 on ancient television sets.

	AM and FM radios weren't any harder to work because the tuning
dial stopped at each end of the band and one could quickly get used to
where the stations were in town in relation to how far to turn the
knob.  One just tuned past all the dull stuff and found one of Tulsa's
two rock-and-roll stations and listened to the good stuff.

	I think the first time I ran across a piece of modern
electronics that had what would later be called accessibility problems
was in the early to mid seventies when I examined a VHF amateur radio
transceiver using a digital synthesizer and a primitive control
interface to set the operating frequency.  One pushed either the Up or
Down button and watched the display until it got close to the desired
frequency at which time, one needed to give the button a tap or two to
get it exactly right.  If one reached the high end of the band, the
next tap reset the counter back to the low end so there was absolutely
nothing to tell you what frequency the display was on at all.

	Unfortunately, that type of design has survived through 30
years of growing complexity and lots of gear uses that model.  It is
absolutely useless if you can't see the display and there is nothing
audible or tactile to let you know what just happened.  When the
device in question gets old and the buttons start failing to make good
contact or begin to bounce more than the de-bouncers can handle,
forget even trying to use it.

	Most televisions and VCR's do have direct numerical channel
entry and that is great, but there is the odd hotel television with
an Up and a Down button on the remote so it makes it hard to return to
say, CNN which may be Channel 43 if you don't know what channel it was
previously on.

	Digital thermostats in houses are a study in these kind of
human engineering problems if you can't see the display.  I beat that
one in my house by buying a thermostat that can be controlled via X10
commands.

	Control systems that blind people can use don't have to be
outrageously expensive or complex, but they do have to replace the
feedback we used to get from clicking wafer switches and pots whose
travel directly related to their settings.

	The biggest problem is that nobody ever thinks about these
issues until they bite.

	Where I work, we have some rooms protected by magnetic card
readers.  Some require both the mag card and a PIN number to be
entered on a touch pad.  Before the year 2000, our card readers had a
grid square pattern molded in to the plastic of the touch pad.  I
could enter my number with no trouble at all since the squares stood
for numbers in the same arrangement as those on a telephone key pad.
If they had been like a calculator, that wouldn't have been any worse
because it would have just meant counting in that order instead of the
telephone order.

	The readers, however, had a piece of firmware in them that
wasn't Y2K compliant and we had to replace them all.  The new readers
were made by the same company but the touch pad was now a featureless
square of plastic with no hint of where the buttons were except for
colored markings.

	When cheap meets ignorance in the engineering world, stand back!

Martin McCormick WB5AGZ  Stillwater, OK 
OSU Information Technology Division Network Operations Group
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist