architecture (Or "micro") A computer whose entire
CPU is
The important characteristics of a microprocessor are the
The first commercial microprocessor was the
Intel 4004 which
appeared in 1971. This was the CPU member of a set of four
originally designed for use in a calculator but was marketed
as "programmable controller for logic replacement". The 4004
is referred to as a 4-bit microprocessor since it processed
only 4 bits of data at a time. This very short word size is
due mainly to the limitations imposed by the maximum
integrated circuit density then achievable.
As integrated circuit densities increased with the rapid
development of integrated circuit manufacturing technology,
the power and performance of the microprocessors also
increased. This is reflected in the increase in the CPU word
size to 4, 8, 16, and by mid-1980s, 32 bits. The smaller
nevertheless suitable as controllers for a very wide range of
applications such as car engines and microwave ovens.
The larger, more recent microprocessors families have
gradually acquired most of the features of large computers.
As the microprocessor industry has matured, several families
of microprocessors have evolved into de facto industrial
standards with multiple manufacturers and numerous "support"
A single chip microprocessor may include other components such
The one-chip microcomputer is in many respects, a landmark
development in computer technology because it reduces the
computer to a small, inexpensive, and easily replaceable
design component.
Microcomputers have given rise to a new class of
are small low cost computers that are designed to sit on an
ordinary office desk or to be portable and fuelled the
computer boom of the late 1980s. The most widespread example
range of personal computers, as have several other companies.
(2002-07-16)