Bell’s Law accounts for the formation, evolution, and
death of computer classes based on logic technology
evolution beginning with the invention of the computer
and the computer industry in the first-generation, vac-uum-tube computers (1950–1960), second-generation,
transistor computers (1958–1970), through the invention and evolution of the third-generation Transistor-Transistor Logic (TTL) and Emitter-coupled Logic
(ECL) bipolar integrated circuits (ICs) from
1965–1985. The fourth-generation MOS and CMOS
ICs enabling the microprocessor (1971) represents a
“break point” in the theory because it eliminated the
other early, more slowly evolving technologies. Moore’s
Law [ 6] is an observation about integrated circuit semiconductor process improvements or evolution since the
first IC chips, and in 2007 Moore extended the predic-
one as a wireless sensor network class. Field Programmable Logic Array chips with tens to hundreds of millions of cells exist as truly universal devices for building
nearly anything.
tion for 10– 15 more years, as expressed in Equation 1.
The evolutionary characteristics of disks, networks,
displays, user interface technologies, and programming environments will not be discussed here.
However, for classes to form and evolve, all technologies must evolve in scale, size, and performance
at their own—but comparable—rates [ 5].
In the first period, the mainframe, followed by minimal computers, smaller mainframes, supercomputers,
and minicomputers established themselves as classes in
the first and second generations and evolved with the
third-generation integrated circuits circa 1965–1990.
In the second or current period, with the fourth generation, marked by the single processor-on-a-chip,
evolving large-scale integrated circuits (1971–present)
CMOS became the single, determinant technology
for establishing all computer classes. By 2010, scalable
CMOS microprocessors combined into powerful,
multiple processor clusters of up to one million independent computing streams are likely. Beginning in
the mid-1980s, scalable systems have eliminated and
replaced the previously established, more slowly evolving classes of the first period that used interconnected
bipolar and ECL ICs. Simultaneously smaller, CMOS
system-on-a-chip computer evolution has enabled
low-cost, small form factor (SFF) or cell-phone-sized
devices (CFSD); PDA, cell phone, personal audio
(and video) devices (PADs), GPS, and camera convergence into a single platform will become the worldwide personal computer, circa 2010. Dust-sized chips
with relatively small numbers of transistors enable the
creation of ubiquitous, radio networked, implantable,
sensing platforms to be part of everything and every-
BELL’S LAW
A computer class is a set of computers in a particular
price range defined by: a programming environment
such as Linux or Windows to support a variety of
applications; a network; and user interface for communication with other information processing systems and people. A class establishes a horizontally
structured industry composed of hardware components through operating systems, languages, application programs and unique content including
databases, games, images, songs, and videos that serves
a market through various distribution channels.
The universal nature of stored-program computers is such that a
computer may be programmed to
replicate function from another class. Hence, over
time, one class may subsume or kill off another class.
Computers are generally created for one or more basic
information processing functions—storage, computation, communication, or control. Market demand for
a class and among all classes is fairly elastic. In 2010,
the number of units sold in classes will vary from tens
for computers costing around $100 million to billions
for SFF devices such as cell phones selling for under
$100. Costs will decline by increasing volume through
manufacturing learning curves (doubling the total
number of units produced results in cost reduction of
10%–15%). Finally, computing resources including
processing, memory, and network are fungible and can
be traded off at various levels of a computing hierarchy
(for example, data can be held personally or provided
globally and held on the Web).
The class creation, evolution, and dissolution
process can be seen in the three design styles and price
trajectories and one resulting performance trajectory
that threatens higher-priced classes: an established
class tends to be re-implemented to maintain its price,
providing increasing performance; minis or minimal-cost computer designs are created by using the technology improvements to create smaller computers
used in more special ways; supercomputer design (the
largest computers at a given time come into existence
by competing and pushing technology to the limit to
meet the unending demand for capability); and the
inherent increases in performance at every class,
including constant price, threaten and often subsume
higher-priced classes.
All of the classes taken together that form the com-