IEEE Spectrum November, 2008 - 14

reflections

By roBerT w. Lucky

I

was considering buying
a new desktop computer,
and I thought I had found
the ideal model. That is, until
I noticed that one little thing
was missing-the activity
light for the hard drive. The
manufacturer probably
saved a few cents by leaving
it out, but that little light
was of some psychological
importance to me. How could
I possibly buy a computer
that was just going to sit there
and not give me any indication that it was working?
A very long time ago, not
long after the dinosaurs went
extinct, I was working on
modem design. At the Bell
System, we had designed
modems the way they were
supposed to be-big, heavy
clunkers with a telephone
handset and an embedded
rotary dial. They were just
24

what the users needed to
connect to their time-shared
mainframes. But one day, a
competitor came out with
a small modem that had
an array of LED lamps on
the front panel, indicating
control signals like clear-tosend as well as data activity.
"What user could possibly
care about such things?" we
joked among ourselves.
Well, it seemed that
people did care about such
things. That little company
sold a lot of modems, and
pretty soon we had indicator
lights on our modems too.
As a consequence, I learned
a key principle of design:
people want blinking lights.
Too many electronic
gadgets are inert steel boxes
with stickers on the bottom
that say something like
"no user-serviceable parts

na * ieee SpectRum * novembeR 2008

inside." Often, you have no
idea whether or not the gadget
is working. When it doesn't
do something you expect it to
do, you stare helplessly at the
box. "Are you alive in there?"
you ask plaintively. But such
entreaties are a waste of
breath. You'd think that the
box could at least hum or
vibrate to communicate life.
A blinking light makes
all the difference-even
though you have no idea
why it's blinking the way
it is. Over the millennia,
humans have evolved a
subconscious ability to recognize and categorize moving visual patterns, like the
flash of tiger fur seen through
dense foliage. So it is with the
activity light. I've had several
cable modems go bad, as well
as several routers, and in
every case I've recognized the
problem by the unfamiliar
blinking patterns of the
activity lights. "Aha," I say to
myself. "That box is sick."
Quite often there is no visible activity on my computer
screen, but I see the harddrive light blinking furiously.
What is it doing? I wonder.
At least the little light tells
me that it is alive, though I
worry about why it is so busy.
At such times I often wish
that there were a special key
labeled "What are you doing?"
I've always found the task
manager rather useless for
this purpose, and no human
being could possibly interpret
the gibberish that fills your

screen following the dreaded
"blue screen of death."
Instead of an unintelligible
binary dump, my imagined
key would give a simple
English explanation: "I'm
busy at the moment reformatting your hard drive," it might
say, "but I'll be through in a
jiffy." Or perhaps, "I'm just
finishing the installation of a
new virus."
Back when dinosaurs
ruled the planet, computers
had lots of indicator lights,
showing the activity on many
of the backplane signals.
When you walked past a
computer center, a dynamic
light show was taking place
inside. Tapes spun and
everything hummed. "Wow,
look at those things think!"
you said to yourself. But
now it seems that the only
indication of life is the roar of
air-conditioning.
So the computer I picked
out had joined the growing
legion of gray boxes devoid
of charisma, its only outward
manifestation of personality
having been sacrificed for
a few cents. Maybe I'm the
only one who cares about
that light now, but I'm not
buying that computer. Its
designers are probably
joking among themselves,
"What user could possibly care about such things?"
Well, I'm one who does.
For want of a cheap little
light, they lost a customer.
Hopefully, they'll put it back
in their next model.
o
www.SpectRum.ieee.oRg

Randi SilbeRman

The Blinking Light
http://www.SpectRum.ieee.oRg
Table of Contents for the Digital Edition of IEEE Spectrum November, 2008
