June 17, 1999
Reinvent the Wheel? This Software Engineer Deconstructs It
By KATIE HAFNER
hen the Sony Corporation put
Aibo, its $2,500 robotic dog, up for
sale on its Web site last month,
John Wharton was determined to get one.
After two hours of trying to get past the
congestion on the site, he finally placed his
Wharton has no plans to give his
mechanical-electronic dog away as a gift, to
keep it around the house as a virtual pet or
to preserve it as a collector's item. After a
period of clinical observation, Wharton
intends to apply screwdriver and pliers,
taking it apart chip by chip, motor by motor,
sensor by sensor.
Peter DaSilva for The New York Times
SECRETS OF FURBY - John Wharton ``reverse-engineers'' a Furby. At right, a partly dismantled Furby and an intact toy sit in front of a computer, which is used to analyze the design.
Wharton is a reverse engineer. For
pure pleasure, he has dissected VCR's, answering machines, floppy disk drives, cellular phones, camcorders and laser printers.
His most satisfying private project of late is
the painstaking dissection of Furby, the
electronics-laden toy, which Wharton
views as a tour de force in compact, highly
intricate yet cost-efficient engineering. To
date, he has dismantled five of them, all to
varying degrees, all with different technical
goals in mind.
Wharton, who is 44, supports himself,
and a handful of expensive and eccentric
hobbies, mostly by working as a highly paid
Wharton is hired as a high-tech detective by law firms whose corporate clients
are involved in patent disputes. They call on
Wharton to take a finished product and
trace it back through thousands of steps to
its original specifications to see where an
infringement may lie. In the last 10 years, he
has been hired to reverse-engineer video
game players, home health devices and
several variations on PC circuitry.
A bearded man with long graying hair,
Wharton has maintained a Zelig-like
presence in Silicon Valley for more than two
In 1978, as a 23-year-old engineer at Intel,
he was the architect of a computer chip
called the 8051. Along with its various offspring, the 8051 is the highest-volume microprocessor the company has ever introduced.
And in 1995, Wharton played a small
role in the capture of Kevin Mitnick, the
computer hacker who recently pleaded
guilty to charges of computer fraud and
In 1981, Wharton quit his job at Intel
and became a consultant, in part because he
was eagerly anticipating the debut of David
Letterman's show, which would be broadcast until 2 A.M. each night. Having to get up
in time to make the 8:10 A.M. sign-in at Intel
every day would deprive him of sufficient
Safeguarding patents by
retracing the inventor's
digital steps. ||
Wharton works from his house in Palo
Alto, Calif., where he lives with a cat named
Zero. "People ask me if I have a dog named
One," he said. (He does not.) His newest pet,
Roo-Roo, a gray and pink Furby with black
spots, is the only Furby to have escaped the
pliers. "He was my firstborn," Wharton
Wharton's name is on the short list of
engineers in Silicon Valley whom law firms
turn to when they need expert technical
help. He does not disguise his self-confidence. David Larson, a partner at Wilson
Sonsini Goodrich & Rosati, a Palo Alto law
firm that has on occasion retained
Wharton as its expert engineer, said that
behind his disheveled appearance was an
extraordinary intelligence, accompanied by
"the arrogance that comes with being so
knowledgeable about certain things."
Wharton's fees -- up to $350 an hour --
occasionally rival those of the lawyers who
But those who know Wharton's work
say he is worth every cent. "When John is
trying to incorporate a new fact about something he's reverse engineering, he can remember 10 other aspects of the design that
will be affected," said Brian Case, a fellow
reverse engineer who has worked with
Wharton on several technical projects.
arrives at his solution faster. That's where
his genius comes in."
The concept of reverse engineering can be
likened to being given a slice of cake,
Wharton said, then being told to unbake it
and to produce the recipe and a list of the
raw ingredients in the process. "Baking a
cake might take a lot of skill, but unbaking a
cake is a more interesting problem,"
In Wharton's view, reverse engineering is the ultimate puzzle. The electronic
age, he noted, has made the process of
ascertaining whether a patent has been
encroached upon much more difficult.
"It used to be that machines were physical," he said. "You could study the gears
and levers of a cotton gin and pretty much
figure out how it worked. But nowadays the
things that pass as machines are virtual.
Cams and levers and drive belts are replaced by source-code statements and subroutines and disk files."
Hence the need for hired guns like
Wharton, people who can extract the bits
and turn them back into a form that judges
and juries can understand.
To understand reverse engineering,
Wharton said, it helps to understand how
electronic products are designed in the first
The design process starts with a written
specification stating how the product works,
the calculations and decisions it has to
make, and how it interacts with the user.
Next, a hardware design engineer determines the circuit elements needed to perform the desired functions -- keyboards or
sensors for input, displays or actuators for
output, and memory for the program and
calculation variables -- and develops schematic diagrams showing how these devices
connect to the microprocessor, the central
Then a software designer writes the
source code, a program to read the relevant
inputs, perform the necessary calculations
and drive the corresponding outputs. Such a
a control program, Wharton said, may
consist of anywhere from 2,000 to 20,000
individual statements combined to form
hundreds of individual subroutines, or subprograms.
A master detective who
traces the evolution of
At this point, the source code consists of
instructions in an abbreviated English-like
form that people can read and modify.
before the program can be executed, it has
to be translated into a combination of bits
(ones and zeros) understandable to the
That translation, performed by programs called assemblers,
leaves the program in a form incomprehensible to humans. "It's as though one were to
flip 100,000 coins and try to make sense of
the pattern of heads and tails that result,"
This information, many tens of thousands
of bits, is loaded into the microprocessor's
memory when the system is manufactured
and causes the hardware circuitry to perform the functions and calculations for
which the product was designed.
In reverse engineering a product,
Wharton said, one goes through the same
steps in opposite order: The engineer removes the program bits from the chip's
memory, uses a disassembler to convert
them back into the program source code,
analyzes that source code to figure out what
the functions were and what they did, and
examines the electronic circuitry to understand how various signals are used. The
engineer can then produce a lengthy written
description of the product's functions, which
should be essentially the same as the manufacturer's original specifications.
With many of the patent projects
Wharton works on, he said, he seldom hears
how a case turns out. Nor does he particularly care to find out.
For Wharton derives much of his
satisfaction from the thrill of the puzzle
itself, like the inner workings of the Furby.
Apart from Dave Hampton, the inventor
and engineer who created Furby and whom
Wharton reveres, Wharton may
understand Furby's innards better than
anyone else. Although he and Hampton
are acquainted, Wharton would never
think to ask Hampton for a road map.
"That would be cheating," he said. "It
would be like asking the guy who wrote the
crossword puzzle for the answers."
One of Wharton's recent projects for
hire involved dissecting a home blood diagnostic instrument. In the middle of the assignment, he took an unexpected trip to
Sydney, Australia, so he hauled everything
with him, including a bag filled with soldering irons, precision knives, voltmeters,
jumper wires, pliers, clippers and screwdrivers, and sat for several evenings in his
hotel room in Sydney, taking the system
apart and studying its circuitry.
"One of the things that's curious about
this work is that it requires time and isolation, being away from distraction," he said.
When not in the thick of a technical
project, Wharton appears to be easily
distracted. A lover of movies, he is a regular
at film festivals, and he has invested in a
small film. He had a bit part in the recent
movie "Ed-TV." He has also witnessed each
solar eclipse visible from North America
since 1991, flying off to Mazatlan or Aruba at
a moment's notice.
Wharton has also been known to apply
his reverse engineering skills to other parts
of his life, with impressive results.
In 1996, when the Letterman show came
to San Francisco, Wharton made a
calculated effort to get noticed. He figured
out which seats the camera would be most
likely to focus on and made sure that he was
He made himself conspicuous
by undoing his ponytail and letting his hair
down and donning a tie-dyed shirt. He ended
up looking "just like the sort of San Francisco hippie" the show's producers would expect to see, he said.
It worked. Letterman himself strode
into the audience, asked Wharton his
name, then asked if he would agree to take a
shower in the host's dressing room -- an
ongoing gag of Letterman's. Wharton happily obliged. The cameras followed
Wharton, from his torso up, as he disrobed, stepped into the shower and lathered
up. On his way back into the audience, clad
in a white bathrobe, he managed to snatch a
copy of the script.
Those who knew Wharton well were
not at all surprised by the triumph.
Wharton was later immortalized on Internet discussion groups as "the Shower Guy"
and was even paid union scale for his appearance.
In fact, Wharton said, he was paid at
the rate for a speaking part because he said
two words on the air, "John" and "sure."
In a similarly well-plotted effort in 1984,
Wharton won a Porsche in a product
design contest after he figured out that the
sponsor, a chip manufacturer, would most
likely reward the entry that best suited its
marketing efforts, not necessarily the best
Reverse engineering, Wharton said, is
not unlike cryptography in that it involves
breaking codes. But cryptography no longer
interests him. "There are now algorithms in
place that cannot be broken," he said. "If
you're looking for difficult problems, you
have to look elsewhere, and reverse engineering is the closest I've found so far."