Dealers of Lightning (85 page)

Bitmap:
A
display in which each dot, or pixel, on the screen corre­sponds to one or more bits in computer memory. Thus turning on a
pattern of bits in memory
can create a
corresponding image on the
screen. Because of the speed at which it can be altered, the
bitmapped display is the essential element of graphical user inter­faces like those developed at
PARC.

Boolean functions:
The mathematical and logical elements at the
heart of digital computing. Boolean functions
are
based on two val­ues, usually represented as true
and
false.
An AND
function, or
AND
gate in a computers circuitry, for example, will return a "true"
value only if both of its inputs are "true," and a "false" value in all
other cases. The
NOT
function returns the converse of its input—•
"true" if the input is "false," and vice versa.
From
such trivial func­tions and their cousins machines can be built that add, subtract, mul­tiply, divide, and do much more.

Byte:
A
string of eight bits (by current convention) large enough to
encode a single character or symbol to
be
input to a computer or
output to its display.

Central processing unit:
The brains of a computer, which supervises
such other parts (or "peripherals") as the disk drives and printers and
controls their access to memory and display.

Internet:
Capitalized, the worldwide network of research and com­mercial computer sites that grew out of the
ARPANET. Lower
case,
any interconnection of discrete local networks.

Killer app:
Abridgment of "killer application."
Any
program that so
perfectly exploits its hardware that it radically speeds the hardware's
adoption. Examples include the Bravo word processing program,
which ran on the Alto, and VisiCalc, the digital spreadsheet that
made the Apple
II
computer a coveted business tool.

Kludge
(pronounced "klooge"): An overelaborate and frequently tem­peramental device or system, often one designed or built over time
to serve incrementally broadened or inconsistent goals. Think Rube
Goldberg.

LAN:
"Local
Area
Network."
A
network of adjacent and usually com­patible computers, often within a single building or a one-kilometer
radius. Numerous rival
LAN
designs emerged during the 1970s,
often promoted by individual computer companies to lock cus­
tomers
into using their proprietary machines (as with
IBM
and the
"token ring"). Ethernets standardization
after
1980 made it the
most common.

Moore
's
Law:
The principle articulated
by
Gordon
Moore
in 1965
that computing power would
exponentially
increase in performance
and diminish in cost over the
years
along
a
predictable curve, so that
digital memory costing $500,000 in
1965
would come all the way
down to a few hundred dollars
by 1998. This
is the force behind the
unprecedented influence technology
exerts
over modern life.

Second system:
From Frederick
Brooks's
The
Mythical Man-Month.
The
often-unsuccessful sequel to a
successful
first project, whether
this is a machine, program,
novel,
or
building. As
Brooks noted, sec­ond systems tend to incorporate all
the extras
that a creative team
was forced by penury or haste
to
leave
out of
their first.
The
result is
a product that is overly complicated,
overly
expensive, and late.

TCP/IP:
"Transmission Control Protocol
over
Internet Protocol." The
set of standardized rules for
the transmission
of data over networks
that allows disparate computer
systems to
remain synchronized
enough to communicate
reliably with each
other. The
"IP"
element
grew out of PARC's development of
the PUP,
or
"PARC
Universal
Packet," which allowed
Xerox
offices
with
incompatible computers
to
communicate with each
other.

Time-sharing:
A
system allowing
several users
to run programs simul­taneously on one computer without interfering with each other.
When computers were costly
and centralized
machines, this was the
standard means of accessing
computer
resources. Technologies such
as the personal computer made
time-sharing
obsolete.

VLSI:
"Very Large Scale Integration."
The
incorporation of millions of
transistors in a single integrated
circuit, or
chip, to provide comput­ing power a quantum leap beyond
that
previously available.
VLSI's
offspring include the Pentium
family of
chips powering many of
today's personal computers and laptops. The design principles of
VLSI
were pioneered by researchers working at
PARC
and the Cali­fornia Institute of Technology.

WYSIWYG
:
'What you see is what you get." Describes a system in
which the computer user interacts with the machine visually through
a screen display that offers instant feedback to inputs such as mouse
clicks and keystrokes. Also refers to programs whose screen
images
—
a document page, for example
—
can be exactly duplicated
by a printer.

Bibliography

Books

Biermann, Alan W.
Great Ideas in Computer Science.
Cambridge,
iMass.: MIT Press, 1990.

Brand, Stewart.
The Media Lab.
New York: Viking, 1987.

Brooks, Frederick P., Jr.
The Mythical Man-Month
(Anniversary Edi­tion). New York: Addison-Wesley, 1995.

Cringely, Robert X.
Accidental Empires: How the Boys of Silicon Val­ley Make Their Empires, Battle Foreign Competition, and Still Can't
Get a Date.
Menlo Park, Calif.: Addison-Wesley, 1992.

DeLamarter, Richard Thomas.
Big Blue: IBM's Use and Abuse of
Power.
New York: Dodd, Mead, 1986.

Dessauer, John H.
My Years with Xerox: The Billions Nobody Wanted.
Garden City, N.Y.: Doubleday, 1971.

Feynmann, Richard I.
The Feynmann Lectures on Computing
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Freiberger, Paul, and Michael Swaine.
Fire in the Valley: The Making
of the Personal Computer.
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1984.

Gelernter, David.
Machine Beauty: Elegance and the Heart of Technol­ogy.
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Gleick, James.
Genius: The Life and Science of Richard I. Feynmann.
New York: Pantheon Books, 1992.

Goldberg, Adele, ed. A
History of Personal Workstations.
Reading,
Mass.: ACM Press, 1988.

Hafner, Katie, and John Markoff.
Cyberpunk: Outlaws and Hackers on
the Computer Frontier.
New York: Simon & Schuster, 1992.

Hafner, Katie, and Matthew Lyon.
Where Wizards Stay up Late: The
Origins of the Internet.
New York: Simon & Schuster, 1996.

Hodges, Andrew.
Alan Turing: The Enigma.
New York: Simon &
Schuster, 1983.

Jackson, Tim.
Inside Intel.
New York: Dutton, 1997.

Jacobson, Gary, and John Hillkirk.
Xerox: American Samurai.
New
York: Macmillan, 1986.

Kearns, David T., and David A. Nadler.
Prophets in the Dark.
New
York: HarperBusiness, 1992.

Kidder, Tracy.
The Soul of a New Machine.
Boston: Little, Brown,
1981.

Lammers, Susan.
Programmers at Work.
Redmond, Wash.: Microsoft
Press, 1986.